diff --git a/misc/git_notes.txt b/misc/git_notes.txt
index efeaa83..0c7dec8 100644
--- a/misc/git_notes.txt
+++ b/misc/git_notes.txt
@@ -3,3 +3,7 @@ to cache my Github username
 
 git config --global user.name "Warren Toomey"
 git config --global user.email wkt@tuhs.org
+
+To bring your own ocal repository up to date with Github:
+ git fetch origin 
+ git merge origin/master
diff --git a/scans/Makefile b/scans/Makefile
new file mode 100644
index 0000000..8d6b259
--- /dev/null
+++ b/scans/Makefile
@@ -0,0 +1,4 @@
+AS7=../tools/as7
+
+system:
+	$(AS7) s?.s sop.s > output
diff --git a/scans/Readme b/scans/Readme
index 2a67a55..08dc3e8 100644
--- a/scans/Readme
+++ b/scans/Readme
@@ -1,4 +1,4 @@
-This area contains the OCR'd version of the PDP-7 scans that are at
+This area contains the OCR'd versions of the PDP-7 scans that are at
 http://www.tuhs.org/Archive/PDP-11/Distributions/research/McIlroy_v0/0*.pdf
 The files should be unaltered versions of the scanned pages.
 
@@ -6,5 +6,30 @@ For modified versions of these files, look in src/cmds and src/sys.
 
 Details of the files:
 
-s1.s: pages 2-3    of 01-s1.pdf, incomplete and with some cruft at the end
+s1.s: pages 2-5    of 01-s1.pdf
+s2.s: pages 7-12   of 01-s1.pdf
+s3.s: pages 14-19  of 01-s1.pdf
+s4.s: pages 21-26  of 01-s1.pdf
+s5.s: pages 28-32  of 01-s1.pdf
+s6.s: pages 34-38  of 01-s1.pdf
+s7.s: pages 41-46  of 01-s1.pdf
+s8.s: pages 48-51  of 01-s1.pdf
+s9.s: pages 53-54  of 01-s1.pdf
+sop.s pages 62-63  of 01-s1.pdf
+sx.s: temp additional symbol defns
+maksys.s: page 64  of 01-s1.pdf
+trysys.s: page 65  of 01-s1.pdf
+
+bc.s:  pages 7-11  of 06-5-12.pdf
+bi.s:  pages 12-19 of 06-5-12.pdf
+bl.s:  pages 3-6   of 06-5-12.pdf
+cas.s: pages 1-17 of 04-cas.pdf
 cat.c: pages 21-23 of 06-5-12.pdf
+
+ind.b:   page 2 of 08-rest.pdf
+lease.b: page 4 of 08-rest.pdf
+
+as.s: pages 32-48 of 05-1-4.pdf
+
+ed1.s: pages 7-20 of 08-rest.pdf
+ed2.s: pages 21-29 of 08-rest.pdf
diff --git a/scans/as.s b/scans/as.s
new file mode 100644
index 0000000..42a6c1b
--- /dev/null
+++ b/scans/as.s
@@ -0,0 +1,980 @@
+" as
+
+   jms init1
+
+assm1:
+   lac eofflg
+   sza
+   jmp assm2
+   lac passno
+   sza
+   jmp finis
+   jms init2
+
+assm2:
+   jms gchar
+   sad d4
+   jmp assm1
+   sad d5
+   jmp assm1
+   lac char
+   dac savchr
+   jms gpair
+   lac rator
+   jms betwen; d1; d6
+   jmp assm3
+   jms expr
+   lac passno
+   sza
+   jms process
+   isz dot+1
+   nop
+   lac dot+1
+   and o17777
+   sad dot+1
+   jmp assm1
+   jms error; >>
+   dzm dot+1
+   jmp assm1
+
+assm3:
+   lac rand
+   sad d2
+   jmp assm4
+   sza
+   jmp assm6
+   lac rator
+   sza
+   jmp assm6
+   lac rand+1
+   jms betwen; dm1; d10
+   jmp assm6
+   dac name
+   tad fbxp
+   dac lvrand
+   lac i lvrand
+   dac name+1
+   isz i lvrand
+   lac o146
+   dac name+2
+   dzm name+3
+   jms tlookup
+   -1
+   dac fbflg
+assm4:
+   lac rand+1
+   tad d4
+   dac lvrand
+   lac rator
+   sza
+   jmp assm5
+   lac dot
+   dac r
+   lac dot+1
+   dac r+1
+   jmp 1f
+
+assm5:
+   jms gpair
+   jms expr
+1:
+   lac r
+   dac i lvrand
+   isz lvrand
+   lac r+1
+   dac i lvrand
+   lac fbflg
+   sna
+   jmp assm1
+   dzm fbflg
+   dzm name+1
+   lac o142
+   dac name+2
+   jms lookup
+   jmp assm4
+
+assm6:
+   jms error; x>
+   jmp assm1
+
+init1: 0
+   lac d1
+   sys write; 1f; 2f-1f
+   dzm passno
+   lac o56040
+   dac dot-4
+   lac o56056
+   dac cmflx-4
+   lac o40040
+   dac dot-3
+   dac dot-2
+   dac dot-1
+   dac cmflx-3
+   dac cmflx-2
+   dac cmflx-1
+   dzm iof
+   jms init
+   jmp i init1
+1:
+   0111012
+2:
+
+init2: 0
+   lac d1
+   dac passno
+   sys write; 1f; 2f-1f
+   jms init
+   lac o17
+   sys creat; 2f
+   dac bfo
+   sys open; 2f; 0
+   dac bfi
+   dzm bufadd
+   jms copyz; buf; 64
+   jmp i init2
+1:
+   0111111;012000
+2:
+   0141056;0157165;0164040;040040
+
+init: 0
+   lac i 017777
+   dac narg
+   lac 017777
+   tad d1
+   dac fname
+   -1
+   dac eofflg
+   jms ioinit
+   dzm savchr
+   dzm comflg
+   lac d1
+   dac dot
+   dzm dot+1
+   dzm cmflx
+   lac d4096
+   dac cmflx+1
+   dzm fbflg
+   jms copyz; fbxp: fbx; 10
+   jmp i init
+
+finis:
+   lac iof
+   sys close
+   jms bufwr
+   lac bfi
+   sys close
+   lac bfo
+   sys close
+   -1
+   tad namsiz
+   cma
+   rcl
+   dac char
+   rcl
+   tad char
+   dac 1f
+   lac o17
+   sys creat; n.out
+   dac bfi
+   sys write; namlst; 1: 0
+   lac bfi
+   sys close
+   sys exit
+
+n.out:
+   0156056;0157165;0164040;040040
+
+process: 0
+   lac dot+1
+   dac lvrand
+   lac dot
+   sad d3
+   jmp proc4
+   sza
+   jmp proc1
+   -1
+   tad cmflx+1
+   cma
+   tad lvrand
+   dac lvrand
+
+proc1:
+   lac lvrand
+   spa
+   jmp proc4
+   and o17700
+   sad bufadd
+   jmp proc2
+   jms bufwr
+   jms copyz; buf; 64
+   lac lyrand
+   and o17700
+   dac bufadd
+   dac 1f
+   lac bfi
+   sys seek; 1: 0; 0
+   spa
+   jmp proc2
+   lac bfi
+   sys read; buf; 64
+
+proc2:
+   lac lyrand
+   and o77
+   jms betwen; dm1; maxsto
+   dac maxsto
+   tad bufp
+   dac lvrand
+   lac r
+   sna
+   jmp proc3
+   sad d3
+   jmp proc5
+   lac cmflx+1
+   tad r+1
+   dac r+1
+
+proc3:
+   lac r+1
+   dac i lvrand
+   jmp i process
+
+proc4:
+   jms error; .>
+   lac d1
+   dac dot
+   dzm dot+1
+   jmp skip
+
+proc5:
+   jms error; u>
+   jmp proc3
+
+bufwr: 0
+   lac bfo
+   sys seek; bufadd: 0; 0
+   isz maxsto
+   lac bfo
+   sys write; bufp: buf; maxstp: -1
+   -1
+   dac maxsto
+   jmp i bufwr
+
+Xnumber: 0
+   dac 3f
+   lac d1000
+   dac 2f
+1:
+   lac 3f
+   cll
+   idiv; 2: 0
+   dac 3f
+   lacq
+   tad o60
+   dac i 8
+   iac 2b
+   cll
+   idiv; 10
+   lacq
+   dac 2b
+   sza
+   jmp 1b
+   jmp i number
+3: 0
+
+getsc: 0
+   lac i getsc
+   dac sctalp
+   isz getsc
+   lac i sctalp
+   dac sctal
+   add o400000
+   dac i sctalp
+   ral
+   lac i sctal
+   szl
+   lrss 9
+   and o177
+   jmp i getsc
+
+putsc: 0
+   and o177
+   lmq
+   lac i putsc
+   dac sctalp
+   isz putsc
+   lac i sctalp
+   dac sctal
+   add o400000
+   dac i sctalp
+   sma cla
+   jmp 1f
+   llss 27
+   dac i sctal
+   lrss 9
+   jmp i putsc
+
+1:
+   lac i sctal
+   omq
+   dac i sctal
+   lacq
+   jmp i putsc
+
+sctalp: 0
+sctal: 0
+
+betwen: 0
+   dac 2f
+   lac i betwen
+   dac 3f
+   isz betwen
+   lac i 3f
+   cma
+   tad 2f
+   spa
+   jmp 2f
+   lac i betwen
+   dac 3f
+   isz betwen
+   lac i 3f
+   cma
+   tad d1
+   tad 2f
+   spa
+1:
+   isz betwen
+   lac 2f
+   jmp i betwen
+2: 0
+3: 0
+
+copyz: 0
+   -1
+   tad i copyz
+   dac 8
+   isz copyz
+   lac i copyz
+   cma
+   tad d1
+   dac 2f
+   isz copyz
+1:
+   dzm i 8
+   isz 2f
+   jmp 1b
+   jmp i copyz
+2: 0
+
+error: 0
+   lac passno
+   sza
+   jmp 1f
+   isz error
+   jmp i error
+1:
+   -1
+   tad mesp
+   dac 8
+   lac i error
+   dac i 8
+   lac o40
+   dac i 8
+   lac rator
+   sad d5
+   jmp 1f
+   lac savchr
+   sad o12
+   jmp 1f
+   lac lineno
+   jmp 2f
+1:
+   -1
+   tad lineno
+2:
+   jms number
+   lac o12
+   dac i 8
+   -2
+   tad mesp
+   cma
+   tad 8
+   dac 1f
+   lac d1
+   sys write; mesp: mes; 1: 0
+   isz error
+   jmp i error
+
+skip:
+   lac rator
+   sad d5
+   jmp assm1
+1:
+   jms gchar
+   sad d5
+   jmp assm1
+   jmp 1b
+
+ioinit: 0
+   jms copyz; iobuf; 64
+   lac iof
+   sys read; iobufp: iobuf; 64
+   sna
+   jms nextfil
+   lac iobufp
+   dac tal
+   -129
+   dac talc
+   jmp i ioinit
+
+nextfil: 0
+   lac d1
+   dac lineno
+   lac iof
+   sza
+   sys close
+nf1:
+   lac narg
+   sad d4
+   skp
+   jmp 1f
+   dzm eofflg
+   jmp i nextfil
+1:
+   tad dm4
+   dac narg
+   lac fname
+   tad d4
+   dac fname
+   sys open; frame: 0; 0
+   dac iof
+   sma
+   lac passno
+   sna
+   jmp nextfil i
+   lac fname
+   dac 1f
+   lac d1
+   sys write; 1; 0; 4
+   lac iof
+   sma
+   jmp 1f
+   lac d1
+   sys write; emes; 2
+   sys exit
+1:
+   lac d1
+   sys write; emes+1; 1
+   jmp i nextfil
+emes:
+   040077;012000
+
+gchar: 0
+   lac savchr
+   dzm savchr
+   sza
+   jmp gch3
+   lac eofflg
+   sza
+   jmp 1f
+   lac o12
+   jmp gch3
+1:
+   isz talc
+   skp
+   jms ioinit
+   jms getsc; tal
+   sna
+   jmp gchar+1
+   sad o177
+   jmp gchar+1
+   sad o12
+   skp
+   jmp 1f
+   dzm comflc
+   isz lineno
+1:
+   sad o42
+   dac comflc
+   dac char
+   lac comflc
+   sza
+   jmp gchar+1
+   lac char
+
+gch3:
+   dac char
+   jms betwn; d0; o200
+   cla
+   tad lactab
+   dac .+1
+   lac 0
+   jmp i gchar
+
+gsymb: 0
+   jms gchar
+   dac rator
+   tad jmpsw1
+   dac 1f
+   lac char
+   sad o74
+   jmp lqot
+   dac namc
+   jms gchar
+   lac char
+   sad o76
+   jmp rqot
+   dac savchr
+   lac namc
+   dac char
+1:
+   jmp 0
+
+jmpsw1:
+   jmp .+1
+   jmp i gsymb
+   jmp i gsymb
+   jmp i gsymb
+   jmp i gsymb
+   jmp gs1
+   jmp i gsymb
+   jmp gs2
+   jmp gs3
+
+badchr:
+   jms error; g>
+1:
+   jms gchar
+   lac char
+   sad o12
+   skp
+   jmp 1b
+   dac savchr
+   jmp gsymb+1
+
+lqot:
+   jms gchar
+   lac o40
+   dac savchr
+   lac char
+   alss 9
+   jmp 1f
+
+rqot:
+   lac namc
+1:
+   dac rand+1
+   lac d7
+   dac rator
+   jmp i gsymb
+
+gs1:
+   jms gchar
+   sad d4
+   jmp gs1
+   lac char
+   dac savchr
+   jmp i gsymb
+
+gs2:
+   lac namep
+   dac tal1
+   -7
+   dac tal1c
+   lac char
+   jms putsc; tal1
+
+gnam1:
+   jms gchar
+   jms betwen; d5; d8
+   jmp gnam3
+   lac char
+   jms putsc; tal1
+   isz tal1c
+   jmp gnam1
+
+gnam2:
+   jms gchar
+   jms betwen; d5; d8
+   skp
+   jmp gnam2
+   lac char
+   dac savchr
+   jms lookup
+   jmp i gsymb
+
+gnam3:
+   lac char
+   dac savchr
+1:
+   lac o40
+   jms putsc; tal1
+   isz tal1c
+   jmp 1b
+   jms lookup
+   jmp i gsymb
+
+gs3:
+   dzm rand+1
+   lac char
+   sad o60
+   jmp 1f
+   lac d10
+   jmp 2f
+1:
+   lac d8
+2:
+   dac num2
+
+num1:
+   lac rand+1
+   cll
+   mul
+num2: 0
+   lacq
+   tad char
+   tad dm48
+   dac rand+1
+   jms gchar
+   sad d7
+   jmp num1
+   lac char
+   dac savchr
+   lac rand+1
+   jms betwen; dm1; d10
+   jmp i gsymb
+   dac name
+   tad fbxp
+   dac name+1
+   lac i name+1
+   dac name+1
+   lac savchr
+   sad o146
+   jmp 1f
+   sad o142
+   skp
+   jmp i gsymb
+   dzm name+1
+1:
+   dac name+2
+   dzm name+3
+   lac d6
+   dac rator
+   jms lookup
+   dzm savchr
+   jmp i gsymb
+
+tlookup: 0
+      jmp 1f
+lookup: 0
+      dzm tlookup
+1:
+   -1
+   tad namlstp
+   dac 8
+   lac namsiz
+   dac namc
+lu1:
+   lac i 8
+   sad name
+   jmp 1f
+   lac d5
+lu2:
+   tad 8
+   dac 8
+   isz namc
+   jmp lu1
+      lac tlookup
+      sna
+      jmp 2f
+      lac fnamep
+      dac rand+1
+      jmp i tlookup
+2:
+   lac name
+   dac i 8
+   lac 8
+   dac rand+1
+   lac name+1
+   dac i 8
+   lac name+2
+   dac i 8
+   lac name+3
+   dac i 8
+   lac d3
+   dac i 8
+   dzm i 8
+   -1
+   tad namsiz
+   dac namsiz
+   jmp i lookup
+1:
+   lac i 8
+   sad name+1
+   jmp 1f
+   lac d4
+   jmp lu2
+1:
+   lac i 8
+   sad name+2
+   jmp 1f
+   lac d3
+   jmp lu2
+1:
+   lac i 8
+   sad name+3
+   jmp 1f
+   lac d2
+   jmp lu2
+1:
+   -3
+   tad 8
+   dac rand+1
+      lac tlookup
+      sza
+      jmp i tlookup
+   jmp i lookup
+namep: name
+
+gpair: 0
+   jms gsymb
+   lac rator
+   sad d4
+   jmp gpair+1
+   jms betwen; dm1; d6
+   jmp gp1
+   dzm rand
+   dzm rand+1
+   jmp i gpair
+gp1:
+   sad d7
+   lac d4
+   tad dm4
+   dac rand
+   jms gsymb
+   lac rator
+   sad d4
+   jmp gp2
+   jms betwen; dm1; d6
+   skp
+   jmp i gpair
+   jms error; x>
+   jmp skip
+gp2:
+   jms gchar
+   jms betwen; d5; d8
+   jmp gp3
+   lac char
+   dac savchr
+   jmp i gpair
+gp3:
+   lac char
+   dac savchr
+   jms gsymb
+   jmp i gpair
+
+expr: 0
+   jms grand
+   -1
+   dac srand
+exp5:
+   lac rand
+   dac r
+   lac rand+1
+   dac r+1
+exp1:
+   lac rator
+   jms betwen; d1; d5
+   jmp exp3
+   dac orator
+   jms gpair
+   jms grand
+   lac orator
+   sad d4
+   jmp exp2
+   jms oper; rand
+   jmp exp1
+exp2:
+   jms pickup
+   lac r
+   dac srand
+   lac r+1
+   dac srand+1
+   jmp expb
+exp3:
+   sad d5
+   jmp exp4
+   jms error; x>
+   smp skip
+exp4:
+   jms pickup
+   jmp i expr
+
+pickup: 0
+   lac srand
+   spa
+   jmp i pickup
+   lac d4
+   jms oper; srand
+   jmp i pickup
+
+grand: 0
+   lac rand
+   sad d2
+   skp
+   jmp i grand
+   lac rand+1
+   tad d4
+   dac rand+1
+   lac i rand+1
+   dac rand
+   isz rand+1
+   lac i rand+1
+   dac rand+1
+   jmp i grand
+
+oper: 0
+   tad opsw
+   dac oper1
+   -1
+   tad i oper
+   dac 8
+   isz oper
+   lac r
+   sad d3
+   jmp oper2
+   lac i 8
+   sad d3
+   jmp oper2
+oper1:
+   jmp 0
+opsw:
+   jmp .-1
+   jmp oplus
+   jmp ominus
+   tad r
+   dac r
+   lac r+1
+   lmq
+   lac i 8
+   omq
+   jmp oret
+oplus:
+   tad r
+   dac r
+   lac r+1
+   tad i 8
+   jmp oret
+ominus:
+   cma
+   tad d1
+   tad r
+   dac r
+   -1
+   tad i 8
+   cma
+   tad r+1
+oret:
+   dac r+1
+   lac r
+   jms betwen; dm1; d2
+   skp
+   jmp i oper
+   jms error; r>
+   lac d1
+   dac r
+   jmp i oper
+oper2:
+   dac r
+   dzm r+1
+   jmp i oper
+
+d0: 0
+d1: 1
+d4096: 4096
+d2: 2
+d3: 3
+d4: 4
+d5: 5
+d6: 6
+d7: 7
+d8: 8
+o12: d10: 10
+dm1: -1
+o40: 040
+o60: 060
+dm48: -48
+o400000: 0400000
+o177: 0177
+dm4: -4
+o200: 0200
+o42: 042
+o142: 0142
+o40040: 040040
+o56056: 056056
+o56040: 056040
+o146: 0146
+o17777: 017777
+d1000: 1000
+o17: 017
+o17700: 017700
+o77: 077
+o74: 074
+o76: 076
+
+namsiz: -2
+namistp: namlst
+fnamep: fakename
+lactab: lac .+1
+8;8;8;8;8;8;8;8
+8;4;5;8;8;8;8;8
+8;8;8;8;8;8;8;8
+8;8;8;8;8;8;8;8
+4;8;8;8;8;8;8;8
+8;8;6;2;4;3;6;8
+7;7;7;7;7;7;7;7
+7;7;0;5;8;1;8;8
+8;6;6;6;6;6;6;6
+6;6;6;6;6;6;6;6
+6;6;6;6;6;6;6;6
+6;6;6;8;8;8;8;8
+8;6;6;6;6;6;6;6
+6;6;6;6;6;6;6;6
+6;6;6;6;6;6;6;6
+6;6;6;8;8;8;8;8
+
+fbflg: .=.+1
+tal: .=.+1
+talc: .=.+1
+tal1: .=.+1
+tal1c: .=.+1
+narg: .=.+1
+lvrand: .=.+1
+eofflg: .=.+1
+namc: .=.+1
+passno: .=.+1
+char: .=.+1
+savchr: .=.+1
+comflg: .=.+1
+rator: .=.+1
+orator: .=.+1
+rand: .=.+2
+srand: .=.+2
+r: .=.+2
+name: .=.+4
+buf: .=.+64
+iobuf: .=.+64
+fbx: .=.+10
+mes: .=.+20
+iof: .=.+1
+bfi: .=.+1
+bfo: .=.+1
+lineno: .=.+1
+
+fakename: .=.+6
+namlst:
+.=.+4
+dot:
+.=.+6
+cmflx:
\ No newline at end of file
diff --git a/scans/bc.s b/scans/bc.s
new file mode 100644
index 0000000..b176f2b
--- /dev/null
+++ b/scans/bc.s
@@ -0,0 +1,288 @@
+" bc
+
+   jmp start
+rinit:
+   jms initio
+   jmp .+1 i
+initio: 0
+   lac inter-1
+   dac fetch
+   jmp rinit
+   jms inter
+inter: 0
+   las
+   and o17
+   sza
+   jms trace
+   lac pc i
+   dac instr
+   lac pc
+   and o10000
+   sna
+   jmp badpc
+   lac sp
+   and o17700
+   sad o17700
+   jmp badsp
+   and o10000
+   sna
+   jmp badsp
+   lac instr
+   sad insasg
+   skp
+   jmp inter i
+   -4
+   tad sp
+   dac t1
+   lac t1 i
+   and o10000
+   sna
+   jmp badasgn
+   lac instr
+   jmp inter i
+
+trace: 0
+   and d1
+   sza
+   jms dtrace
+   las
+   and d2
+   sza
+   jms ddisp
+   las
+   and d4
+   sza
+   jms histog
+   las
+   and d8
+   sza
+   jmp stop
+   jmp trace i
+
+itrace: 0
+   lac pc
+   dac 8
+   lac 8 i
+   dac instr
+   lac 8
+   jms octal; -4
+   law 040
+   jms putc
+   lac instr
+   cll; lrs 14
+   tad lacop
+   dac .+1
+   lac ..
+   jms putc
+   law 040
+   jms putc
+   lac instr
+   jms octal; -4
+   
+   lac instr
+   sad inslitr
+   skp
+   jmp 1f
+   law 040
+   jms putc
+   lac 8 i
+   jms octal; -6
+1:
+   law 012
+   jms putc
+   jms flush
+   jmp dtrace i
+
+ddisp: 0
+   jms dspinit
+   lac dspbp
+   dac 8
+   lac dp
+   sad olddp
+   skp
+   jms dspblk
+   lac pc
+   jms dspnt
+   lac sp
+   jms dspnt
+   lac lastv
+   jms dspnt
+   -1
+   dac B i
+   lac pbs i
+   sza
+   jmp .-2
+   jmp ddisp i
+
+dspblk: 0
+   lac dspbuf
+   dac 8
+   lac dp
+   dac t1
+   dzm t2
+1:
+   lac t1
+   sna
+   jmp 1f
+   lac o216000 " dx -20
+   dac 8 i
+   lac t2
+   tad o20
+   dac t2
+   lac t1
+   tad d1
+   dac t3
+   lac t3 i
+   jms dspnt
+   lac t1 i
+   dac t1
+   jmp 1b
+1:
+   lac o160020 " sx 20
+   tad t2
+   dac dspbuf i
+   dac 8 i
+   lac 8
+   dac dspbp
+   jmp dspblk i
+
+dspnt: 0
+   and o7777
+   lrss 2
+   xor o164000 " sy 0
+   dac 8 i
+   lac o17010
+   dac 8 i
+   jmp dspnt i
+
+dspinit: 0
+   -1
+   tad dspinit
+   dac dspinit
+   -300
+   tad lastv
+   dac lastv
+   dac dspbuf
+   -1
+   dac dspinit i
+   dac dspbuf i
+   dzm olddp
+   lac dspbuf
+   sys capt
+   law 13
+   sys sysloc
+   dac pbs
+   jmp dspinit i
+
+histog: 0
+   jms hisinit
+   lac pc
+   lrs 6
+   and o77
+   tad histbuf
+   dac t1
+   isz t1 i
+   jmp histog i
+   jmp .
+
+hisinit: 0
+   -1
+   tad hisinit
+   dac hisinit
+   -1
+   dac hisinit i
+   -64
+   dac t1
+   tad lastv
+   dac lastv
+   dac histbuf
+   tad dm1
+   dac 8
+1:
+   dsm 8 i
+   isz t1
+   jmp 1b
+   jmp hisinit i
+
+histbuf: 0
+olddp: 0
+dspbuf: 0
+dspbp: 0
+instr: 0
+obs: 0
+inslitr: n 5
+insasg: b 1
+o17: 017
+d8: 8
+o77: 077
+o10000: 010000
+d5: 5
+o60: 060
+o7777: 07777
+o216000: 0216000
+o160020: 0160020
+o20: 020
+o164000: 0164000
+o17010: 017010
+o17700: 017700
+d2: 2
+
+lacop: lac .
+   a>;b>;c>;f>;n>;s>;t>;u>;x>;y>
+
+badpc:
+   jms flush
+   lac d1
+   sys write; mpc; mpcs
+   jmp stop
+badsp:
+   jms flush
+   lac d1
+   sys write; msp; msps
+   jmp stop
+badasgn:
+   jms flush
+   lac d1
+   sys write; mas; mass
+   jmp stop
+mpc:
+   012;<pc>;012
+mpcs = .-mpc
+msp:
+   012;<sp>;012
+msps = .-msp
+mas:
+   012;<as>;012
+mass = .-mas
+
+octal: 0
+   lmq
+   lac d5
+   tad octal i
+   cma
+   dac 2f
+   sna
+   jmp 3f
+1:
+   llss 3
+   isz 2f
+   jmp 1b
+3:
+   lac octal i
+   dac 2f
+   lacq
+   dac 2f+1
+1:
+   lac 2f+1
+   lmq
+   ecla llss 3
+   tad o60
+   jms putc
+   lac 2f+1
+   alss 3
+   dac 2f+1
+   isz 2f
+   jmp 1b
+   isz octal
+   jmp octal i
+2: 0;0
diff --git a/scans/bi.s b/scans/bi.s
new file mode 100644
index 0000000..322163f
--- /dev/null
+++ b/scans/bi.s
@@ -0,0 +1,433 @@
+" bi
+
+start:
+   jms initio
+   -1
+   tad .main
+   dac pc
+
+fetch:
+   lac pc i
+   imq
+   and o17777
+   dac addr
+   ecla lls 4
+   tad .+3
+   dac .+1
+   jmp .. i
+   jmp . i
+   autop; binop; consop; ifop; etcop; setop; traop
+   unaop; extop; aryop
+
+
+ifop:
+   -2
+   tad sp
+   dac sp
+   lac sp i
+   dac t1
+   lac t1 i
+   sza
+   jmp fetch
+   -1
+   tad addr i
+   dac pc
+   jmp fetch
+
+autop:
+   lac addr
+   tad dp
+   dac sp i
+   isz sp
+   isz sp
+   jmp fetch
+
+binop:
+   -2
+   tad sp
+   dac sp
+   tad dm1
+   dac t4
+   tad dm1
+   dac t3
+   lac t3 i
+   dac t1
+   lac sp i
+   dac t2
+   lac t4
+   dac t3 i
+   lac addr
+   tad .+3
+   dac .+1
+   jmp .. i
+   jmp . i
+   basg; bor; band; beq; bne; ble; blt; bge; bgt; brsh; blsh
+   badd; bmin; bmod; bmul; bdiv
+
+basg:
+   lac t2 i
+   dac t1 i
+   dac t4 i
+   jmp fetch
+
+bor:
+   lac t1 i
+   lmq
+   lac t2 i
+   omq
+   dac t4 i
+   jmp fetch
+
+band:
+   lac t2 i
+   and t2 i
+   dac t4 i
+   jmp fetch
+
+beq:
+   lac t1 i
+   xor t2 i
+   sna cla
+   lac d1
+   dac t4 i
+   jmp fetch
+
+bne:
+   lac t1 i
+   xor t2 i
+   sza
+   lac d1
+   dac t4 i
+   jmp fetch
+
+ble:
+   lac t2 i
+   cma
+   tad t1 i
+   spa cla
+   lac d1
+   dac t4 i
+   jmp fetch
+
+blt:
+   lac t1 i
+   cma
+   tad t2 i
+   sma cla
+   lac d1
+   dac t4 i
+   jmp fetch
+
+bge:
+   lac t1 i
+   cma
+   tad t2 i
+   spa cla
+   lac d1
+   dac t4 i
+   jmp fetch
+
+bgt:
+   lac t2 i
+   cma
+   tad t1 i
+   sma cla
+   lac d1
+   dac t4 i
+   jmp fetch
+
+brsh:
+blsh:
+   hlt
+
+badd:
+   lac t1 i
+   tad t2 i
+   dac t4 i
+   jmp fetch
+
+bmin:
+   lac t1 i
+   cma
+   tad t2 i
+   cma
+   dac t4 i
+   jmp fetch
+
+bmod:
+   lac t2 i
+   dac .+4
+   lac t1 i
+   cll; idiv; ..
+   dac t4 i
+   jmp fetch
+
+bmul:
+   lac t2 i
+   dac .+4
+   lac t1 i
+   cll; mul; ..
+   lacq
+   dac t4 i
+   jmp fetch
+
+bdiv:
+   lac t2 i
+   dac .+4
+   lac t1 i
+   cll; idiv; ..
+   lacq
+   dac t4 i
+   jmp fetch
+
+consop:
+   lac sp
+   tad d1
+   dac sp i
+   isz sp
+   iac addr
+   dac sp i
+   isz sp
+   jmp fetch
+
+etcop:
+   lac addr
+   tad .+3
+   dac .+1
+   jmp .. i
+   jmp . i
+   mcall; mark; call; vector; litrl; goto; retrn; escp
+
+mcall:
+   -2
+   tad sp
+   dac t1
+   lac t1 i
+   dac t2
+   -1
+   tad t2 i
+   imq
+   lac dp
+   dac t1 i
+   lac t1
+   dac dp
+   isz t1
+   iac pc
+   dac t1 i
+   lacq
+   dac pc
+   jmp fetch
+
+mark:
+   -1
+   tad sp
+   dac t2
+   tad dm1
+   dac t1
+   lac t1 i
+   dac t3
+   lac t3 i
+   dac t2 i
+   lac ap
+   dac t1 i
+   lac t1
+   dac ap
+   jmp fetch
+
+call:
+   lac ap
+   tad d1
+   dac 8
+   dac 9
+1:
+   lac 8 i
+   dac t1
+   lac t1 i
+   dac 9 i
+   isz 8
+   -1
+   tad sp
+   sad B
+   skp
+   jmp 1b
+   lac ap i
+   img
+   lac dp
+   dac ap i
+   lac ap
+   dac dp
+   isz ap
+   -1
+   tad ap i
+   dac t1
+   lac pc
+   dac ap i
+   lacq
+   dac ap
+   lac t1
+   dac pc
+   jmp fetch
+
+vector:
+   -2
+   tad sp
+   dac sp
+   tad dm2
+   dac t1
+   lac sp i
+   dac t2
+   lac t1 i
+   dac t3
+   lac t3 i
+   tad t2 i
+   dac t1 i
+   jmp fetch
+
+litrl:
+   lac sp
+   tad d1
+   dac sp i
+   isz sp
+   lac pc i
+   dac sp i
+   isz sp
+   jmp fetch
+
+goto:
+   -2
+   tad sp
+   dac sp
+   lac sp i
+   dac t1
+   -1
+   tad t1 i
+   dac pc
+   jmp fetch
+   
+retrn:
+   -2
+   tad sp
+   dac sp
+   lac sp i
+   dac t1
+   lac t1 i
+   lmq
+   lac dp
+   dac sp
+   dac t1
+   lac sp i
+   sna
+   jmp stop
+   dac dp
+   isz sp
+   lac sp
+   dac t1 i
+   lac sp i
+   dac pc
+   lacq
+   dac sp i
+   isz sp
+   jmp fetch
+
+escp:
+   law 2
+   tad pc
+   dac t1
+   jmp t1 i
+
+setop:
+   lac addr
+   tad dp
+   dac sp
+   jmp fetch
+
+traop:
+   -1
+   tad addr
+   dac pc
+   jmp fetch
+
+unaop:
+   -1
+   tad sp
+   dac t3
+   tad dm1
+   dac t2
+   lac t2 i
+   dac t1
+   lac t3
+   dac t2 i
+   lac addr
+   tad .+3
+   dac .+1
+   jmp .. i
+   jmp . i
+   uadr; umin; uind; unot
+
+badr:
+   lac t1
+   dac t3 i
+   jmp fetch
+
+bmin:
+   -1
+   tad t1 i
+   cma
+   dac t3 i
+   jmp fetch
+
+bind:
+   lac t1 i
+   dac t2 i
+   jmp fetch
+
+bnot:
+   lac t1 i
+   sna cla
+   lac d1
+   dac t3 i
+   jmp fetch
+
+extop:
+   lac addr
+   dac sp i
+   isz sp
+   isz sp
+   jmp fetch
+
+aryop:
+   lac addr
+   tad dp
+   dac t1
+   tad d1
+   dac t1 i
+   jmp fetch
+
+a = 040000
+b = a+a
+c = b+a
+f = c+a
+n = f+a
+s = n+a
+t = s+a
+u = t+a
+x = u+a
+f = x+a
+
+d1: 1
+dm1: -1
+dm2: -2
+o17777: 017777
+
+:1: 0
+:2: 0
+:3: 0
+:4: 0
+:ddr: 0
+
+pc = 017
+
+sp: stack
+dp: stack
+ip: stack
+stack: 0
\ No newline at end of file
diff --git a/scans/bl.s b/scans/bl.s
new file mode 100644
index 0000000..95111f1
--- /dev/null
+++ b/scans/bl.s
@@ -0,0 +1,194 @@
+" bl
+
+jmp start
+
+.array: .+1
+   s 2
+   n 8
+   n 7
+   -1
+   tad sp i
+   cma
+   tad lastv
+   dac lastv
+   imq
+   lac sp
+   tad d1
+   dac sp i
+   isz sp
+   lacq
+   dac sp i
+   isz sp
+   jmp fetch
+
+.read: .+1
+   s 2
+   n 8
+   n 7
+   lac sp
+   tad d1
+   dac sp i
+   isz sp
+   jms getc
+   dac sp i
+   isz sp
+   jmp fetch
+
+.write: .+1
+   s 2
+   n 8
+   n 7
+   lac sp i
+   dac t1
+   lrss 9
+   jms putc
+   lac t1
+   jms putc
+   jmp fetch
+
+.flush: .+1
+   n 8
+   n 7
+   jms flush
+   jmp fetch
+
+getc: 0
+   lac iflg
+   dzm iflg
+   sza
+   jmp getc i
+   lac cibufp
+   sad eibufp
+   jmp 1f
+   lac cibufp i
+   and o777
+   dac iflg
+   lac cibufp i
+   isz cibufp
+   lrss 9
+   jmp getc i
+1:
+   lac .fin
+   sys read; ibufp: ..; 64
+   sna spa
+   jmp 1f
+   tad ibufp
+   dac eibufp
+   lac ibufp
+   dac cibufp
+   jmp getc+1
+1:
+   lac 0o4
+   jmp getc i
+
+putc: 0
+   and 0777
+   sna
+   jmp putc i
+   imq
+   lac oflg
+   sza
+   jmp 1f
+   lacq
+   alss 9
+   dac cobufp i
+   dac oflg
+   jmp putc i
+1:
+   lac cobufp i
+   omq
+   dac cobufp i
+   dac cobufp i
+   dzm oflg
+   isz cobufp
+   lac cobufp
+   sad eobufp
+   skp
+   jmp putc i
+   lac .fout
+   sys write; obufp: ..; 64
+   lac obufp
+   dac cobufp
+   jmp putc i
+
+stop:
+   jms flush
+   las
+   sma
+   sys save
+   sys exit
+
+flush: 0
+   lac oflg
+   sza
+   isz cobufp
+   lac cobufp
+   cma
+   tad obufp
+   cma
+   sna
+   jmp flush i
+   dac 1f+1
+   lac obufp
+   dac 1f
+   lac .fout
+   sys write; 1: :.; ..
+   lac obufp
+   dac cobufp
+   dzm oflg
+   jmp flush i
+
+initio: 0
+   lac 017777 i
+   sad d4
+   jmp 2f
+   sad d8
+   jmp 1f
+
+   law 9
+   tad 017777
+   dac .+3
+   law 017
+   sys creat; ..
+   spa
+   jmp stop
+   dac .fout
+1:
+   law 5
+   tad 017777
+   dac .+2
+   sys open; ..; 0
+   spa
+   jmp stop
+   dac .fin
+2:
+   lac lastv
+   dac eibufp
+   dac cibufp
+   -64
+   tad lastv
+   dac lastv
+   dac ibufp
+   lac lastv
+   dac eobufp
+   -64
+   tad lastv
+   dac lastv
+   dac obufp
+   dac cobufp
+   dzm oflg
+   jmp initio i
+
+.fin: 0
+.fout: 1
+eibufp: 0
+cibufp: 0
+iflg: 0
+eobufp: 0
+cobufp: 0
+oflg: 0
+lastv: 017770
+
+o777: 0777
+d4:o4: 4
+d8: 8
\ No newline at end of file
diff --git a/scans/cas.s b/scans/cas.s
new file mode 100644
index 0000000..f4e61fc
--- /dev/null
+++ b/scans/cas.s
@@ -0,0 +1,1059 @@
+"** 04-cas.pdf page 1
+" cas
+
+   narg = i 017777
+
+   lac 017777
+   tad d5
+   dac name1
+   tad d4
+   dac name 2
+   lac narg
+   sad d4
+   jmp 1f
+   sad d8
+   jmp 2f
+   jmp 3f
+1:
+   law ttyout
+   dac name1
+2:
+   law ttyin
+   dac name2
+3:
+   sys open; name2: 0; 0
+   sma
+   jmp 1f
+   lac name2
+   dac 2f
+   lac d1
+   sys write; 2: 0; 4
+   lac d1
+   sys write; mes; 2
+   sys exit
+1:
+   sys open; name1: 0; 1
+   sma
+   jmp 1f
+   lac name1
+   dac 2f
+   lac o17
+   sys creat; 2: 0
+   sma
+   jmp 1f
+   lac name1
+   dac 2f
+   lac d1
+   sys write; 2: 0; 4
+   lac d1
+   sys write; mes; 2
+   sys exit
+mes:
+   040077;012
+1:
+   dzm nchar
+   dzm x
+   dzm y
+   dzm parflg
+   dzm nins
+   dzm nwds
+   lac bufp
+   dac 10
+
+advanc:
+"** 04-cas.pdf page 2
+   lac nchar
+   dzm nchar
+   sza
+   jmp adv1
+   lac d2
+   sys read; char; 1
+   sna
+   jmp done
+   lac char
+   and o777
+   dac nchar
+   lac char
+   lrss 9
+
+adv1:
+   sna
+   jmp advanc
+   dac char
+   lac labflg
+   sna
+   jmp 2f
+   lac char
+   sad o12
+   skp
+   jmp 1f
+   dzm labflg
+   dac i 11
+   jmp advanc
+1:
+   dac i 11
+   jmp advanc
+2:
+   lac parflg
+   sza
+   jmp atoz
+   lac char
+   sad o12
+   jmp advanc
+   sad o72
+   skp
+   jmp 1f
+   -4
+   dac labflg
+   dac mod3
+   jms wbuf "???
+   lac lbufp
+   dac 11
+   lac o170072
+   dac i 10
+   lac o12
+   dac i 10
+   lac o60
+   dac i 10
+   isz nwds
+   isz nwds
+   isz nwds
+   jmp advanc
+1:
+   sad o170
+   skp
+   jmp 1f
+"** 04-cas.pdf page 3
+   dzm vis
+   jmp advanc
+1:
+   sad o166
+   skp
+   jmp 1f
+   lac visbit
+   dac vis
+   jmp advanc
+1:
+   sad 0162
+   skp
+   jmp letr
+   isz mod3
+   skp
+   jmp 2f
+   lac o60060
+1:
+   dac i 10
+   isz nwds
+   isz mod3
+   jmp 1b
+2:
+   lac o12
+   dac i 10
+   isz nwds
+   lac lbufp
+   dac 11
+    1: "???
+   lac i 11
+   sad o12
+   jmp 1f
+   dac i 10
+   isz nwds
+   jmp 1b
+1:
+   lac o75170
+   dac i 10
+   isz nwds
+   lac ob1
+   dac i 10
+   isz nwds
+   lac sp
+   dac i 10
+   isz nwds
+   lac nins
+   dzm nins
+   tad o100
+   lmq
+   llss 10
+   cla
+   llss 3
+   alss 6
+   llss 3
+   tad o60060
+   dac i 10
+   cla
+   llss 3
+   alss 6
+   llss 3
+   tad o60060
+"** 04-cas.pdf page 4
+   dac i 10
+   cla
+   llss 3
+   alss 6
+   llss 3
+   tad o60060
+   dac i 10
+   lac nwds
+   tad d4
+   dac nwds
+   lac o12012
+   dac i 10
+   dzm x
+   dzm y
+   jmp advanc
+letr:
+   tad om141 "???
+   spa
+   jmp error
+   tad dm16
+   sma "???
+   jmp error
+   cma "???
+   tad dm3
+   dac ny
+   -1
+   dac parflg
+   jmp advanc
+
+atoz:
+   lac char
+   tad om141
+   spa
+   jmp error
+   tad dm14
+   sma
+   jmp error
+   tad d14
+   dac nx
+
+loop:
+   -1
+   tad x
+   cma
+   tad nx
+   dac delx
+   -1
+   tad y
+   cma
+   tad ny
+   dac dely
+   " generate direction
+
+   lac delx
+   sna
+   jmp c1
+   spa
+   jmp c2
+   lac dely  ;"dx ,gr, 0
+   sna
+   jmp c3
+"** 04-cas.pdf page 5
+   spa
+   jmp c4
+   lac d1
+   jmp b
+c3:
+   lac d2
+   jmp a
+c4:
+   lac d3
+   jmp b
+
+c1:
+   lac dely
+   sna
+   jmp out
+   spa
+   jmp c5
+   cla
+   jmp a
+c5:
+   lac d4
+   jmp a
+c2:
+   lac dely
+   sna
+   jmp c6
+   spa
+   jmp c7
+   lac d7
+   jmp b
+c6:
+   lac d6
+   jmp a
+c7:
+   lac d5
+   jmp b
+   "
+   "
+a:
+   dac direc
+   lac delx
+   sma
+   jmp 1f
+   cma
+   tad d1
+   dac delx
+1:
+   lac dely
+   sma
+   jmp 1f
+   cma
+   tad d1
+1:
+   tad dlex
+   tad dm4
+   sma
+   cla
+   tad d3
+   dac dist
+   tad incxp
+   dac tmp
+"** 04-cas.pdf page 6
+   lac i tmp
+   dac incx
+   lac dist
+   tad incyp
+   dac tmp
+   lac i tmp
+   dac incy
+   jmp com
+   "
+b:
+   dzm dist
+   dac direc
+   lac incxt
+   dac incx
+   lac incyt
+   dac incy
+   "
+com:
+   isz nins
+   lac dist
+   alss 4
+   xor vis
+   xor direc
+   isz mod3
+   skp
+   jmp 1f
+2:
+   lmq
+   llss 12
+   cla
+   llss 3
+   alss 6
+   llss 3
+   tad o60060
+   dac i 10
+   isz nwds
+   jmp 3f
+1:
+   dac tmp
+   lac o12060
+   dac i 10
+   isz nwds
+   -3
+   dac mod3
+   lac tmp
+   jmp 2b
+3:
+   lac direc
+   tad incx
+   dac tmp
+   lac i tmp
+   tad x
+   dac x
+   lac direc
+   tad incy
+   dac tmp
+   lac i tmp
+   tad y
+   dac y
+   jmp loop
+"** 04-cas.pdf page 7
+out:
+   lac nx
+   dac x
+   lac ny
+   dac y
+   dzm parflg
+   jmp advanc
+
+done:
+   lac d2
+   sys close
+   jms wbuf
+   lac d3
+   sys close
+   sys exit
+
+error:
+   lac d1
+   sys write; char; 1
+   lac d1
+   sys write; mes; 2
+   dzm parflg
+   dzm labflg
+   jmp advanc
+
+wbuf: 0
+   lac nwds
+   dac 1f
+   lac d3
+   sys write; buf; 1f: 0; "???
+   dzm nwds
+   lac bufp
+   dac 10
+   jmp i wbuf
+
+d1: 1
+d2: 2
+d3: 3
+d4: 4
+d5: 5
+d6: 6
+d7: 7
+d8: 8
+o12: 012
+o75170: 075170
+ob1: 055142
+
+sp: 053060
+o60: 060
+o60060: 060060
+o73: 073
+d6: 6 "seems like a dupe
+d14: 14
+dm14: -14
+dm16: -16
+om141: -0141 "???
+dm3: -3
+dm4: -4
+o162: 0162
+o166: 0166
+"** 04-cas.pdf page 8
+o17: 017
+o777: 0777
+o72: 072
+o170: 0170
+o10000: 010000
+o20000: 020000
+o200000: 0200000
+o41: 041
+ttyin:
+   0164164;0171151;0156040;040040
+ttyout:
+   0164164;0171157;0165164;040040
+
+char: .=.+1
+parflg: .=.+1
+labflg: .=.+1
+obuf: .=.+8
+x: .=.+1
+y: .=.+1
+nx: .=.+1
+ny: .=.+1
+vis: .=.+1
+nchar: .=.+1
+   "
+incxp:incxt
+incyp:incyt
+incxt: x1;x2;x3;x4
+incyt: y1;y2;y3;y4
+   "
+x1: 0;1;1;1;0;-1;-1;-1
+x2: 0;2;2;2;0;-2;-2;-2
+x3: 0;3;3;3;0;-3;-3;-3
+x4: 0;4;4;4;0;-4;-4;-4
+y1: 1;1;0;-1;-1;-1;0;1
+y2: 2;2;0;-2;-2;-2;0;2
+y3: 3;3;0;-3;-3;-3;0;3
+y4: 4;4;0;-4;-4;-4;0;4
+delx: .=.+1
+dely: .=.+1
+incx: .=.+1
+incy: .=.+1
+direc: .=.+1
+dist: .=.+1
+visbit: 010
+mod3: .=.+1
+tmp: .=.+1
+buf: .=.+500
+bufp: buf-1
+lbuf: .=.+10
+lpbufp: lbuf-1
+nwds: .=.+1
+o1770072: 0170072
+nins: .=.+1
+o100: 0100
+o12012: 012012
+o12060: 012060
+
+
+
+
+
+"** 04-cas.pdf page 9
+:ca
+v
+af
+nl "???
+x
+hd
+v
+hi
+x
+mn
+r
+
+:cb
+x
+ga
+v
+gi
+ik
+kk
+mi "???
+ma
+aa
+ai
+ck
+ek
+gi
+x
+mn
+r
+
+:cc
+x
+kk
+v
+mi "???
+mc
+ka
+ca
+ac
+ai
+dl
+x
+mn
+r
+
+:cd
+v
+aa
+ai
+ck
+kk
+mi
+ma
+x
+mn
+r
+
+:ce
+x
+mk
+v
+ma
+"** 04-cas.pdf page 10
+aa
+ak
+x
+gh
+v
+ga
+x
+mn
+r
+
+:cf
+v
+aa
+ak
+x
+gh
+v
+ga
+x
+mn
+r
+
+:cg
+x
+gf
+v
+gk
+nk
+x
+kk
+v
+mi
+mc
+ka
+ca
+ac
+ai
+dl
+x
+mn
+r
+
+:ch
+x
+aa
+v
+na
+x
+gb "???
+v
+gk
+x
+ak
+v
+nk
+x
+mn
+r
+
+:ci
+x
+"** 04-cas.pdf page 11
+md
+v
+mi
+x
+lf
+v
+af
+x
+ad
+v
+ai
+x
+mn
+r
+
+:cj
+x
+ka
+v
+mc
+mg
+ki
+ai "???
+x
+ag
+v
+al "???
+x
+mn
+r
+
+:ck
+x
+aa
+v
+na
+x
+ak
+v
+ia
+x
+mk
+v
+fe
+x
+mn
+r
+
+:cl
+x
+aa
+v
+ma
+mk
+x
+mn
+r
+
+:cm
+v
+aa
+"** 04-cas.pdf page 12
+hf
+ak
+nk
+x
+mn
+r
+
+:cn
+x
+ak
+v
+mk
+aa
+na
+x
+mn
+r
+
+:co
+x "???
+ai
+v
+ch
+ei
+ck
+ai
+ac
+ca
+ka
+mc "???
+mi
+kk
+ck
+x
+mn
+r
+
+:cp
+v
+aa
+ai
+ck
+ek
+gi
+ga
+x
+mn
+r
+
+:cq
+x
+mc
+v
+ka
+ca
+ac
+ai
+ck
+kk
+mi
+mc
+"** 04-cas.pdf page 13
+x
+jh
+v
+nl
+x
+mn
+r
+
+:cr
+v
+aa
+ai
+ck
+ek
+gi
+ga
+x
+mk
+v
+gf
+x
+mn
+r
+
+:cs
+x
+ka
+v
+mc
+mi
+kk
+ik
+gi
+gc
+ea
+ca
+ac
+ai
+dl
+x
+mn
+r
+
+:ct
+x
+aa
+v
+al
+x
+mf
+v
+af
+x
+mn
+r
+
+:cu
+x
+aa
+v
+ka
+"** 04-cas.pdf page 14
+mc
+ml "???
+kk
+x
+ak
+v
+lk
+x
+mn
+r
+
+:cv
+x
+aa
+v
+mf
+x
+ak
+v
+mf
+x
+mn
+r
+
+:cw
+x
+aa
+v
+mc
+af
+x
+ak
+v
+mi
+af
+x
+mn
+r
+
+:cx
+v
+gf
+x
+ak
+v
+gf
+x
+aa
+v
+nl
+x
+mn
+r
+
+:cy
+x
+aa
+v
+if
+x
+ak
+"** 04-cas.pdf page 15
+v
+if
+nf
+x
+mn
+r
+
+:cz
+x
+aa
+v
+ak
+ma
+ml
+x
+mn
+r
+
+:c0
+x
+ck
+v
+ai
+ac
+ca
+ka
+mc
+mi
+kk
+ck
+x
+mn
+r
+
+:c1
+x
+ce
+v
+af
+mf
+x
+md
+v
+mi
+x
+mn
+r
+
+:c2
+x
+ca
+v
+ac
+ai
+ck
+ek
+gi
+gc
+ia
+ma
+ml "???
+"** 04-cas.pdf page 16
+mc
+mi
+kk
+hk
+fi
+fc
+ha
+x
+mn
+r
+
+:c7
+x
+aa
+v
+ak
+nb
+x
+mn
+r
+
+:c8
+x
+gc
+v
+ea
+ca
+ac
+ai
+ck
+ek
+gi
+gc
+ia
+ka
+mc
+mi
+kk
+ik
+gi
+x
+mn
+r
+
+:c9
+x
+ka
+v
+mc
+mi
+kk
+ck
+ai
+ac
+ca
+fa
+hc
+hi
+fk
+x
+mn
+"** 04-cas.pdf page 17
+x
+mn
+r
+
+:c3
+x
+aa
+v
+ak
+fe
+fi
+hk
+kk
+mi
+mc
+x
+ka
+v
+nd
+x
+mn
+r
+
+:c4
+x
+mh
+v
+ah
+ia
+ll
+x
+mn
+r
+
+:c5
+x
+ak
+v
+aa
+fa
+fi
+hk
+kk
+mi
+mc
+x
+ka
+v
+nd
+x
+mn
+r
+
+:c6
+x
+ck
+v
+ai
+ac
+ca
+ka
+
+" The end of file seems abrupt, every other :cX section ends with:
+" x
+" mn
+" r
diff --git a/scans/ed1.s b/scans/ed1.s
new file mode 100644
index 0000000..20bde48
--- /dev/null
+++ b/scans/ed1.s
@@ -0,0 +1,771 @@
+"** 08-rest.pdf page 8
+"[handwritten page number top right of scan - 1]
+" ed1
+   lac d1
+   sys write; 1f; 3
+   lac o17
+   sys creat; tname
+   spa
+   sys save
+   dac sfo
+   sys open; tname; 0
+   spa
+   sys save
+   dac sfi
+   -1
+   tad lnodp
+   dac zermp
+   tad d1
+   dac zerop
+   dac dot
+   tad d1
+   dac eofp
+   dzm i eofp
+   dzm i zerop
+   dzm lastre
+   dzm fbuf
+   lac d1
+   dac dskadr
+   dac wrlfg
+   dzm diskin
+ "o------------> [scan markup]
+   jmp advanc
+1:
+   <ed>; <it>; 012
+advanc:
+   jms rline
+   lac linep
+   dac tal
+   dzm adrflg
+   jms addres
+   jmp comand
+   -1
+   dac adrflg
+   lac addr
+   dac addr1
+   dac addr2
+1:
+   lac char
+   sad o54
+   jmp 2f
+   sad o73
+   skp
+   jmp chkwrp
+   lac addr
+   dac dot
+2:
+   jms addres
+   jmp error
+   lac addr2
+   dac addr1
+   lac addr
+   dac addr2
+   jmp 1b
+"** 08-rest.pdf page 9
+"[handwritten page number top right of scan - 2]
+chkwrp:
+   -1
+   tad addr1
+   jms betwen; d1; addr2
+   jmp error
+
+comand:
+   lac char
+   sad o141
+   jmp ca
+   sad o143
+   jmp cc
+   sad o144
+   jmp cd
+   sad o160
+   jmp cp
+   sad o161
+   jmp cq
+   sad o162
+   jmp cr
+   sad o163
+   jmp cs
+   sad o167
+   jmp cw
+   sad o12
+   jmp cnl
+   sad o75
+   jmp ceq
+   jmp error
+ca:
+   jms newline
+   jms setfl
+   lac addr2
+   dac dot
+ca1:
+   jms rline
+   lac line
+   sad o56012
+   jmp advanc
+   jms append
+   jmp ca1
+
+cc: cd:
+   jms newline
+   jms setdd
+   lac addr1
+   sad zerop
+   jmp error
+   dac dot
+   tad dm1
+   dac 9
+   lac addr2
+   dac 8
+2:
+   lac i 8
+   dac i 9
+   sza
+   jmp 2b
+"??? illegible line cut off - dac 0, lac 0, something else???
+"** 08-rest.pdf page 10
+"[handwritten page number top right of scan - 3]
+   dac eofp
+   lac char
+   sad o144
+   jmp advanc
+   -1
+   tad dot
+   dac dot
+   jmp ca1
+
+cp:
+   jms newline
+cp1:
+   jms setdd
+   lac addr1
+   sad zerop
+   jmp error
+1:
+   lac addr1
+   dac dot
+   lac i addr1
+   jms gline
+   dac 2f
+   lac d1
+   sys write; line; 2: 0
+   lac addr1
+   sad addr1
+   jmp advanc
+   tad d1
+   dac addr1
+   jmp 1b
+
+cq:
+   jms newline
+   lac adrflg
+   sza
+   jmp error
+   sys exit
+
+cr:
+   jms setfl
+   lac addr2
+   dac dot
+   jms rname
+ "------------>  [scan markup]
+   sys open; fbuf; 0
+   spa
+   jmp error
+   dac tfi
+   lac linep
+   dac tal
+   dzm num
+1:
+   lac tfi
+   sys read; tbuf; 64
+   sza
+   jmp 2f
+   lac tfi
+   sys close
+   jms number
+   jmp advanc
+2:
+"??? illegible line cut off - cma, sma, something else?
+"** 08-rest.pdf page 11
+"[handwritten page number top right of scan - 4]
+   tad d1
+   rcl
+   dac c1
+   lac tbufp
+   dac tal1
+2:
+   jms getsc; tal1
+   sna
+   jmp 3f
+   jms putsc; tal
+   isz num
+   sad o12
+   skp
+   jmp 3f
+   lac tal
+   add o400000
+   and o17777
+   cma
+   tad linep
+   cma
+   dac linsiz
+   jms append
+   lac linep
+   dac tal
+3:
+   isz c1
+   jmp 2b
+   jmp 1b
+cw:
+   jms setfl
+   lac i addr1
+   sna
+   jmp error
+   jms rname
+   lac o17
+   sys creat; fbuf
+   spa
+   jmp error
+   dac tfi
+   -128
+   dac c2
+   lac tbufp
+   dac tal1
+   dzm num
+1:
+   lac i addr1
+   jms gline
+   rcl
+   cma
+   tad d1
+   dac c1
+   lac linep
+   dac tal
+2:
+   jms getsc; tal
+   sna
+   jmp 3f
+   isz num
+   jmp putsc; tal1
+   isz c2 "???
+"** 08-rest.pdf page 12
+"[handwritten page number top right of scan - 5]
+   jmp 3f
+   lac tfi
+   sys write; tbuf; 64
+   -128
+   dac c2
+   lac tbufp
+   dac tal1
+3:
+   isz c1
+   jmp 2b
+   lac addr1
+   sad addr2
+   jmp 1f
+   isz addr1
+   jmp 1b
+1:
+   lac tal1
+   sma cla
+   jmp 1f
+   jms putsc; tal1
+1:
+   -1
+   tad tufp
+   cma
+   tad tal1
+   dac 1f
+   lac tfi
+   sys write; tbuf; 1: 0
+   lac tfi
+   sys close
+   jms number
+   jmp advanc
+
+cn1:
+   lac adrflg
+   sna
+   jmp 1f
+   lac addr2
+   dac addr1
+   jmp cp1
+1:
+   lac dot
+   tad d1
+   sad eofp
+   jmp error
+   dac dot
+   jmp cp1
+
+ceq:
+   jms newline
+   jms setfl
+   lac addr2
+   dac dot
+   cma
+   tad zerop
+   cma
+   dac num
+   jms number
+   jmp advanc
+
+setdd: 0
+"** 08-rest.pdf page 13
+"[handwritten page number top right of scan - 6]
+   lac adrflg
+   sza
+   jmp i setdd
+   lac dot
+   dac addr1
+   dac addr2
+   jmp i setdd
+
+setfl: 0
+   lac adrflg
+   sza
+   jmp i setfl
+   lac zerop
+   tad d1
+   dac addr1
+   -1
+   tad eofp
+   dac addr2
+   jmp i setfl
+
+newline: 0
+   jms getsc; tal
+   sad o12
+   jmp i newline
+   jmp error
+
+addres: 0
+   dzm minflg "..) [stray scan mark?]
+   -1
+   dac addr
+ad1:
+   jms getsc; tal
+ad2:
+   jms betwen; d47; d56
+   skp
+   jmp numb
+   sad o40 "[o40 circled in scan]
+   jmp ad1 "[hand drawn check mark follows operand in scan]
+   sad o11
+   jmp ad1 "[hand drawn check mark follows operand in scan]
+           "[check mark underlined in scan]
+   sad o55
+   jmp amin "[hand drawn check mark follows operand in scan]
+   sad o56
+   jmp adot "[hand drawn check mark follows operand in scan]
+   sad o53
+   jmp ad1 "[hand drawn check mark follows operand in scan]
+   sad o44
+   jmp adol "[hand drawn check mark follows operand in scan]
+   sad o57
+   jmp fsrch "[hand drawn check mark follows operand in scan]
+   sad o77
+   jmp bsrch "[hand drawn check mark follows operand in scan]
+   dac char
+   lac minflg
+   sza
+   jmp error
+   lac addr
+   sma
+   isz addres
+   jmp i addres
+"** 08-rest.pdf page 14
+"[handwritten page number top right of scan - 7]
+adot:
+   lac minflg
+   sza
+   jmp error
+   lac addr
+   sma
+   jmp error
+   lac dot
+   dac addr
+   jmp ad1
+
+adol:
+   lac minflg
+   sza
+   jmp error
+   lac addr
+   sma
+   jmp error
+   -1
+   tad eofp
+   dac addr
+   jmp ad1
+
+amin:
+   -1
+   dac minflg
+   jmp ad1
+
+numb:
+   dac char
+   sad o60
+   jmp 1f
+   lac d10
+   jmp 2f
+1:
+   lac d8
+2:
+   dac 2f
+   dzm num
+1:
+   lac num
+   cll; mul; 2: 0
+   lacq
+   tad char
+   tad dm48
+   dac num
+   jms getsc; tal
+   dac char
+   jms betwen; d47; d58
+   skp
+   jmp 1b
+   lac minflg
+   sna
+   jmp 1f
+   -1
+   tad num
+   cma
+   dac num
+   dzm minflg
+1:
+   lac addr
+"** 08-rest.pdf page 15
+"[handwritten page number top right of scan - 8]
+   spa
+   lac zerop
+   tad num
+   dac addr
+   jms betwen; zermp; eofp
+   jmp error
+   lac char
+   jmp ad2
+
+number: 0
+   lac d100000
+   dac n1
+   law tbuf-1
+   dac 8
+n0:
+   lac num
+   cll; idiv; n1: 0
+   dac num
+   lacq
+   tad d48
+   dac i 8
+   lac n1
+   cll; idiv; 10
+   lacq
+   dac n1
+   sza
+   jmp n0
+   lac o12
+   dac i 8
+   law tbuf-1
+   dac 8
+   dac 9
+   -5
+   dac n1
+n2:
+   lac i 8
+   sad d48
+   skp
+   jmp n3
+   dzm i 9
+   isz n1
+   jmp n2
+n3:
+   lac d1
+   sys write; tbuf; 7
+   jmp i number
+
+rname: 0
+   lac fbufp
+   dac tal1
+   -8
+   dac c1
+1:
+   jms getsc; tal
+   sad o40
+   jmp 1b
+   sad o12
+   jmp 1f
+   jms putsc; tal1
+   isz c1
+   jmp 1b
+"** 08-rest.pdf page 16
+"[handwritten page number top right of scan - 9]
+   jmp i rname
+1:
+   lac tal1
+   sad fbufp
+   skp
+   jmp 1f
+   lac fbuf
+   sna
+   jmp error
+   jmp i rname
+1:
+   lac o40
+   jms putsc; tal1
+   isz c1
+   jmp 1b
+   jmp i rname
+
+gline: 0
+   dac glint1
+   jms getdsk
+   lac glint1 " [these 6 lines were surrounded by a box
+   adn o17777 " that was Xed out with an arrow pointing to it]:
+   tad dskbfp " --
+   dac ital   "|\/|
+   lac linep  "|/\|<---
+   dac otal   " --
+1:
+   lac ital
+   sad edskbfp
+   skp
+   jmp 2f
+   lac diskin
+   tad d1024
+   jms getdsk
+   lac dskbfp
+   dac ital
+2:
+   jms getsc; ital
+   jms putsc; otal
+   sad o12
+   skp
+   jmp 1b
+   lac otal
+   sma
+   jmp 1f
+   cla
+   jms putsc; otal
+1:
+   lac linpm1
+   cma
+   tad otal
+   jmp i gline
+
+rline: 0
+   lac linep
+   dac tal
+
+1:
+   cla
+   sys read; char; 1
+   lac char
+"** 08-rest.pdf page 17
+"[handwritten page number top right of scan - 10]
+   lrss 9
+   jms esc
+   lac char
+   and o777
+   jms esc
+   jmp 1b
+
+esc: 0
+   sna
+   jmp i esc
+   jms putsc; tal
+   sad o12
+   jmp 2f
+   sad o100
+   jmp 1f
+   sad o43
+   skp
+   jmp i esc
+   -1
+   tad tal
+   dac tal
+   and o17777
+   sad linpm1
+   jmp 1f
+   jmp i esc
+
+1:
+   lac linep
+   dac tal
+   jmp i esc
+
+2:
+   lac tal
+   sma cla
+   jmp 1f
+   jms putsc; tal
+1:
+   -1
+   tad linep
+   cma
+   tad tal
+   dac linsiz
+   jmp i rline
+
+getsc: 0
+   lac i getsc
+   dac sctalp
+   isz getsc
+   lac i sctalp
+   dac sctal
+   add o400000
+   dac i sctal
+   ral
+   lac i sctal
+   szl
+   lrss 9
+   and o777
+   jmp i getsc
+
+putsc: 0
+   and o777
+"** 08-rest.pdf page 18
+"[handwritten page number top right of scan - 11]
+   lmq
+   lac i putsc
+   dac sctalp
+   isz putsc
+   lac i sctalp
+   dac sctal
+   add o400000
+   dac i sctalp
+   sma cla
+   jmp 1f
+   llss 27
+   dac i sctal
+   lrss 9
+   jmp i putsc
+
+1:
+   lac i sctal
+   and o777000
+   omq
+   dac i sctal
+   lacq
+   jmp i putsc
+
+append: 0
+   -1
+   tad eofp
+   dac 8
+   cma
+   tad dot
+   dac apt1
+1:
+   lac i 8
+   dac i 8
+   -3
+   tad 8
+   dac 8
+   isz apt1
+   jmp 1b
+   isz eofp
+   dzm i eofp
+   isz dot
+   jms addline
+   jmp i append
+
+addline: 0
+   lac dskadr
+   dac i dot
+   jms getdsk "[line crossed out - scan markup]
+   -1
+   tad linsiz
+   cma
+   dac apt1
+   law line-1
+   dac 8
+   lac dskadr "[line crossed out - scan markup]
+   and o1777  "[line crossed out - scan markup]
+   tad dskbfp "[line crossed out - scan markup]
+   dac otal   "[line crossed out - scan markup]
+   lac dskadr "[line crossed out - scan markup]
+   tad linsiz "[line crossed out - scan markup]
+   dac dskadr "[line crossed out - scan markup]
+"** 08-rest.pdf page 19
+"[handwritten page number top right of scan - 12]
+1:
+   lac otal    " [these 9 lines were surrounded by a box
+   sad edskbfp " that was Xed out]:
+   skp         " --
+   jmp 2f      "|\/|
+   lac diskin  "|/\|
+   tad d1024   " --
+   jms getdsk  "
+   lac dskbfp  "
+   dac otal    "
+2: "[line crossed out - scan markup]
+   lac i 8
+   dac i otal "[line crossed out and a note that looks like *jous prtwrd*]
+   isz otal
+   dzm wrflg "[line crossed out - scan markup]
+   isz apt1
+   jmp 1b
+   jmp i addline
+
+
+getdsk: 0                  "[the entire getdsk procedure was surrounded
+   and o776000             " by a box that was Xed out]:
+   sad diskin              " --
+   jmp i getdsk            "|\/|
+   dac 2f                  "|/\|
+   lac wrflg               " --
+   sza                     "
+   jmp 3f                  "
+   lac diskin              "
+   dac 1f                  "
+   lac sfo                 "
+   sys seek; 1: 0; 0       "
+   lac sfo                 "
+   sys write; dskbuf; 1024 "
+   lac d1                  "
+   dac wrflg               "
+3:                         "
+   lac 2f                  "
+   dac diskin              "
+   lac sfi                 "
+   sys seek; 2: 0; 0       "
+   spa                     "
+   jmp i getdsk            "
+   lac sfi                 "
+   sys read; dskbuf; 1024  "
+   jmp i getdsk            "
+
+betwen: 0
+   dac bett1
+   lac i betwen
+   dac bett2
+   isz betwen
+   lac i bett2
+   cma
+   tad bett1
+   spa
+   jmp 1f
+   lac i betwen
+   dac bett2
+   isz betwen
+   -1
+   tad i bett2
+"** 08-rest.pdf page 20
+"[handwritten page number top right of scan - 13]
+   cma
+   tad bett1
+   spa
+1:
+   isz betwen
+   lac bett1
+   jmp i betwen
+
+error:
+   lac d1
+   sys write; 1f; 1
+   jmp advanc
+1:
+   077012
\ No newline at end of file
diff --git a/scans/ed2.s b/scans/ed2.s
new file mode 100644
index 0000000..3345e98
--- /dev/null
+++ b/scans/ed2.s
@@ -0,0 +1,519 @@
+"** 08-rest.pdf page 21
+"[handwritten page number top right of scan - 14]
+" ed2
+
+cs:
+   jsm getsc; tal
+   sad o40
+   jmp cs
+   sad o12
+   jmp error
+   dac delim
+   jms compile
+   lac tbufp
+   dac tal1
+1:
+   jms getsc; tal
+   sad delim
+   jmp 1f
+   sad o12
+   jmp error
+   jms putsc; tal1
+   jmp 1b
+1:
+   lac o12
+   jms putsc; tal1
+   jms newline
+   jms setdd
+   lac addr1
+   sad zerop
+   jmp error
+1:
+   dac addr1
+   lac i addr1
+   jms execute
+   jmp 2f
+   lac addr1
+   dac dot
+   law line-1
+   dac 8
+   law nlist-1
+   dac 9
+   -64
+   dac c1
+3:
+   lac i 8
+   dac i 9
+   isz c1
+   jmp 3b
+   -1
+   tad fchrno
+   dac linsiz
+   rcr
+   szl
+   xor o400000
+   tad linep
+   dac tal1 "???
+   lac tbufp
+   dac tal
+3:
+   jms getsc; tal
+   sad o12
+   jmp 3f
+   jms putsc; tal1
+   isz linsiz "???
+"** 08-rest.pdf page 22
+"[handwritten page number top right of scan - 15]
+   jmp 3b
+3:
+   -1
+   tad lcrhno
+   rcr
+   szl
+   xor o400000
+   tad nlistp
+   dac tal
+3:
+   jms getsc; tal
+   jms putsc; tal1
+   isz linsiz
+   sad o12
+   skp
+   jmp 3b
+   jms addline
+2:
+   lac addr1
+   sad addr2
+   jmp advanc
+   tad d1
+   jmp 1b
+
+fsrch:
+   dac delim
+   jms compile
+   jms srcsav
+   lac dot
+floop:
+   tad d1
+   dac addr
+   lac i addr
+   sza
+   jmp 1f
+   lac zerop
+   dac addr
+   jmp 2f
+1:
+   jms execute
+   jmp 2f
+   jms srcres
+   jmp ad1
+2:
+   lac addr
+   sad dot
+   jmp error
+   jmp floop
+
+bsrch:
+   dac delim
+   jms compile
+   jms srcsav
+   lac dot
+   dad zerop
+   lac eofp
+bloop:
+   tad dm1
+   dac addr
+   lac i addr
+"** 08-rest.pdf page 23
+"[handwritten page number top right of scan - 16]
+   sza
+   jmp 1f
+   lac eofp
+   dac addr
+   jmp 2f
+1:
+   jms execute
+   jmp 2f
+   jms srcres
+   jmp ad1
+2:
+   lac addr
+   sad dot
+   jmp error
+   jmp bloop
+
+srcsav: 0
+   lac minflg
+   sza
+   jmp error
+   lac addr
+   sma
+   jmp error
+   law line-1
+   dac 8
+   law tbuf-1
+   dac 9
+   -64
+   dac c1
+1:
+   lac i 8
+   dac i 9
+   isz c1
+   jmp 1b
+   jmp i srcsav
+
+srcres: 0
+   law tbuf-1
+   dac 8
+   law line-1
+   dac 9
+   -64
+   dac c1
+1:
+   lac i 8
+   dac i 9
+   isz c1
+   jmp 1b
+   jmp i srcres
+
+compile: 0
+   law compbuf-1
+   dac 8
+   dzm prev
+   dzm compflg
+
+cadvanc:
+   jms getsc; tal
+   sad delim
+   jmp cdone
+   dac compflg "???
+"** 08-rest.pdf page 24
+"[handwritten page number top right of scan - 17]
+   dzm lastre
+   sad o12
+   jmp error
+   "sad o133
+   "jmp chrcls
+   sad o136 "???
+   jmp beglin
+   sad o44
+   jmp endlin
+   "sad o52
+   "jmp clsure
+   dac 1f
+   jmp comp
+   1; jms matchar; 1: 0; 0
+   jmp cadvanc
+
+cdone:
+   lac compflg
+   sna
+   jmp 1f
+   dac lastre
+   jms comp
+   1; jms found; 0
+   jmp i compile
+1: "???
+   lac lastre
+   sna
+   jmp error
+   jmp i compile
+
+chrcls:
+  jmp error
+
+beglin: "???
+   jms comp
+   1; jms matbol; 0
+   dzm prev
+   jmp cadvanc
+
+endlin: "???
+   jms comp
+   1; jms mateol; 0
+   dzm prev
+   jmp cadvanc
+
+clsure:
+   lac prev
+   sna
+   jmp error
+   tad d1
+   dac 1f
+   jms comp
+   1; jms matclo; 1: 0; 0
+   dzm prev
+   jmp cadvanc
+
+comp: 0 "???
+   -1
+   tad comp
+   dac 9
+   lac 8 "???
+"** 08-rest.pdf page 25
+"[handwritten page number top right of scan - 18]
+   dac prev
+1: "???
+   lac i 9
+   sna
+   jmp i 9
+   dac i 8
+   jmp 1b
+
+execute: 0
+   jms gline
+   lac linep
+   dac tal1
+   dzm charno
+   dzm fchrno
+   dzm lchrno
+   lac jmpclist
+   dac trvect
+   lac jmpnlist
+   dac trvect+1
+   lac jmpxchg
+   dac i trvect+1
+   jmp 1f
+
+exchg: "???
+   lacq
+   sad o12
+   jmp i execute
+   lac jmpxchg
+   dac i 8
+1: "???
+   lac trvect
+   lmq
+   lac trvect+1
+   dac trvect
+   lacq
+   dac trvect+1
+   tad dm1
+   dac 8
+   jms getsc; tal1
+   lmq
+   isz charno
+   jms compbuf
+charno:
+   0
+trvect:
+   0;0
+
+matchar: 0 "???
+   -2
+   tad matchar
+   dac exret
+   lac i exret
+   dac exret
+   lacq
+   sad i matchar
+   skp
+   jmp 1f
+   lac matchar
+   adn o17777
+   tad jms1
+   dac i 8 "??? [unreadable page cutoff]
+"** 08-rest.pdf page 26
+"[handwritten page number top right of scan - 19]
+   lac i exret
+   dac i 8
+1: "???
+   isz exret
+   jmp i exret
+
+found: 0
+   -2
+   tad found
+   dac exret
+   lac i exret
+   dac exret
+   lac fchrno
+   sza
+   jmp 1f
+   isz execute
+   jmp 2f
+1: "???
+   sad i exret
+   jmp 1f
+   cma
+   tad i exret
+   spa
+   jmp 2f
+   jmp 3f
+1: "???
+   lac charno
+   cma
+   tad charno
+   spa
+   jmp 3f
+2: "???
+   lac i exret
+   dac fchrno
+   lac charno
+   dac lchrno
+3: "???
+   isz exret
+   jmp i exret
+
+matbol: 0 "???
+   lac charno
+   sad d1
+   jmp 1f
+   lac matbol
+   jmp 2f
+1: "???
+   lac matbol
+   jmp 3f
+
+mateol: 0 "???
+   lacq
+   sad o12
+   jmp 1f
+   lac mateol
+2: "???
+   tad dm2
+   dac exret
+   lac i exret
+   dac 9
+   "??? [line is cut off in scan, maybe lac i 8 or jmp i 9]
+"** 08-rest.pdf page 27
+"[handwritten page number top right of scan - 20]
+1: "???
+   lac mateol
+3: "???
+   tad dm3
+   dac 9
+   lac i 9
+   isz 9
+   dac i 9
+   jmp i 9
+
+matclo: 0 "???
+   -2
+   tad matclo
+   dac exret
+   lac i exret
+   dac cloret
+   lac i cloret
+   dac 1f
+   dac 2f
+   lac i matclo
+   dac exret
+   jms i exret; 1: 0
+   isz matclo
+   jms i matclo; 2: 0
+   isz cloret
+   jmp i cloret
+
+"??? the remainder of this scan had an unreadable first character
+"??? I did the best I could to recreate the characters appropriately
+o1: 1
+o133: 0133
+dm3: -3
+o136: 0136
+dm2: -2
+o52: 052
+o57: 057
+o77: 077
+o40: 040
+o12: 012
+d47: 47
+d58: 58
+dm48: -48
+d10: 10
+d8: 8
+d48: o60: 060
+d100000: 100000
+o44: 044
+o53: 053
+o56: 056
+o55: 055
+o11: 011
+o400000: 0400000
+o17777: 017777
+o144: 0144
+dm1: -1
+o56012: 056012
+o777: 0777
+o100: 0100
+o43: 043
+o777000: 0777000
+o75: 075
+o167: 0167
+o161: 0161
+"** 08-rest.pdf page 28
+"[handwritten page number top right of scan - 21]
+o160: 0160
+o143: 0143
+o141: 0141
+o1777: 01777
+d1024: 1024
+o776000: 0776000
+o162: 0162
+o163: 0163
+o73: 073
+o54: 054
+o17: 017
+
+tname:
+   0145056;0164155;0160040;040040
+tbufp: tbuf
+linep: line
+nlistp: nlist
+fbufp: fbuf
+dskbfp: dskbuf "[line crossed out - scan markup]
+edskbfp: dskbuf+1024 "[line crossed out - scan markup]
+lnodp: lnodes
+linpm1: line-1
+jmpclist: jmp clist
+jmpnlist: jmp nlist
+jmpxchg: jmp xchg
+jms1: jms 1
+tal: .=.+1
+exret: .=.+1
+cloret: .=.+1
+delim: .=.+1
+prev: .=.+1
+compflg: .=.+1
+tal1: .=.+1
+c1: .=.+1
+ital: .=.+1
+otal: .=.+1
+diskin: .=.+1
+glint: .=.+1
+c2: .=.+1
+num: .=.+1
+zermp: .=.+1
+minflg: .=.+1
+adrflg: .=.+1
+dot: .=.+1
+addr: .=.+1
+addr1: .=.+1
+addr2: .=.+1
+eofp: .=.+1
+zerop: .=.+1
+dskadr: .=.+1
+linsiz: .=.+1
+tfi: .=.+1
+fchrno: .=.+1
+lchrno: .=.+1
+lastre: .=.+1
+bett1: .=.+1
+bett2: .=.+1
+wrflg: .=.+1
+apt1: .=.+1
+"[page cuts off one label]
+"** 08-rest.pdf page 29
+"[handwritten page number top right of scan - 22]
+sfo: .=.+1
+sctal: .=.+1
+sctalp: .=.+1
+char: .=.+1
+fbuf: .=.+4  "not sure if this is fbuf, but
+tbuf: .=.+64 "there is a write; tbuf; 64 call
+line: .=.+64
+nlist: .=.+50
+"??? ?list: .=.+50, unable to determine label
+compbuf: .=.+100
+dskbuf: .=.+1 "[line crossed out - scan markup]
+lnodes: .=.+1000
diff --git a/scans/ind.b b/scans/ind.b
new file mode 100644
index 0000000..151be09
--- /dev/null
+++ b/scans/ind.b
@@ -0,0 +1,26 @@
+main $(
+   extrn read, write;
+   auto i, c, state, line 100;
+
+loop:
+   state = i = 0;
+loop1:
+   c = read();
+   if(c==4) return;
+   if(c==';' & state==0) state = 2;
+   if((c<'0' ^ c>'9'&c<'a' ^ c>'z') & state==0) state = 1;
+   line[i] = c;
+   i = i+1;
+   if(c!=012) goto loop1;
+   if(state==2 ^ i==1) goto noi;
+   write('  ');
+   write(' ');
+noi:
+   i = 0;
+loop3:
+   c = line[i];
+   write(c);
+   i = i+1;
+   if(c!=012) goto loop3;
+   goto loop;
+$)
diff --git a/scans/lease.b b/scans/lease.b
new file mode 100644
index 0000000..df6c6df
--- /dev/null
+++ b/scans/lease.b
@@ -0,0 +1,20 @@
+main $(
+   auto ch;
+   extrn read, write;
+
+   goto loop;
+   while (ch != 04)
+      $( if (ch > 0100 & ch < 0133)
+            ch = ch + 040;
+      if (ch==015) goto loop;
+      if (ch==014) goto loop;
+      if (ch==011)
+       $( ch = 040040;
+          write(040040);
+          write(040040);
+          $)
+      write(ch);
+   loop:
+      ch = read()&0177;
+      $)
+  $)
\ No newline at end of file
diff --git a/scans/maksys.s b/scans/maksys.s
new file mode 100644
index 0000000..e04585a
--- /dev/null
+++ b/scans/maksys.s
@@ -0,0 +1,52 @@
+"** 01-s1.pdf page 64 -- handwritten maksys
+" copy a.out to disk track 18x
+" where x is the argument
+
+   lac 017777 i; sad d8; skp; jmp error
+   lac 017777; tad d5; dac track
+   lac i track; lrss 9; tad om60
+   spa; jmp error; dac track
+   tad dm10; sma; jmp error
+
+   sysopen; a.out; 0
+   spa; jmp error
+   sys read; bufp; buf; 3072
+   sad .-1
+   jmp error
+
+   dscs
+   -3072; dslw
+   lac bufp; dslm
+   lac track; alss 8; xor o300000; dsld
+   lac o30000; dsls
+   dssf; jmp .-1
+   dsrs; spa; jmp error
+   -1024; dslw
+   lac d3072; dslm
+   lac track; alss 8; xor o300110; dsld
+   lac o3000; dsls
+   dssf; jmp .-1
+   dsrs; spa; jmp error
+   sys exit
+
+error:
+   lac d1; sys write; 1f; 2
+   sys exit
+1: 077077;012
+
+dm10: -10
+dm5: 5
+om60: -060
+o300000: 0300000
+o300100: 0300110
+d8: 8
+d3072: 3072
+o3000: 03000
+d1: 1
+a.out:
+   <a.>;<ou>;<t 040;040040
+
+track: .=.+1
+
+buf:
+
diff --git a/scans/s1.s b/scans/s1.s
index 355c501..3a8fead 100644
--- a/scans/s1.s
+++ b/scans/s1.s
@@ -102,31 +102,94 @@ swap: 0
    dac u.ulistp i
    ion
    jmp dskswap; 07000
+   lac u.dspbuf
+   sna
+   jmp 2f
+   law dspbuf
+   jms movdsp
+2:
+   iof
+   lac o600000
+   tad 9f+t i
+   dac 9f+t i
+   ion
+   jms dskswap; 06000
+   lac u.swapret
+   dac swap
+   lac o20
+   dac maxquant
+   lac u.dspbuf
+   sza
+"** 01-s1.pdf page 4
+   jms movdsp
+3:
+   dzm uquant
+   iof
+   jmp swap i
+t = t+1
 
-" For now, this stuff is defined so that
-" the assembler doesn't complain about it
+swp:
+   jmp .
+   .save; .getuid; .open; .read; .write; .creat; .seek; .tell
+   .close; .link; .unlink; .setuid; .rename; .exit; .time; .intrp
+   .chdir; .chmod; .chown; badcal; .sysloc; badcal; .capt; .rele
+   .status; badcal; .smes; .rmes; .fork
+swn:
+    .-swp-1 i
 
+.intrp:
+   lac u.ac
+   dac u.intflg
+   jmp okexit
+
+.sysloc:
+   lac u.ac
+   and o17777
+   jms betwen; d1; locn
+      jms error
+   tad locsw
+   dac .+1
+   lac ..
+   dac u.ac
+   jmp sysexit
+
+locsw:
+   lac .
+   iget; inode; userdata; sysdata; copy; copyz; betwen; dskrd
+   dskwr; dskbuf; dpdata; namei; pbsflgs; alloc; free; dspdata
+   crdata
+locn:
+   .-locsw-1
 
-pibreak: 23
-u.ac: 100
-u.mq: 3
-u.rq: 3
-copy: 7
-.savblk: 0
-.insys: 0
-uquant: 0
-betwen: 0
-maxquant: 0
-laci: 0
-swp: 0
-badcal: 0
-coldentry: 0
-halt: 0
-dskio: 0
-sysdata: 0
-dskbuf: 0
-o7000: 07000
-o20001: 020001
 chkint: 0
-.save: 0
-lookfor: 0
+   lac .insys
+   sza
+   jmp chkint i
+   lac .int1
+   sna
+   jmp 1f
+   sad u.ofiles+2
+   jmp 2f
+1:
+   lac .int2
+   sna
+   jmp chkint i
+   sad chkint i
+   sad u.ofiles+2
+   skp
+   jmp chkint i
+   dzm .int2
+   jmp 1f
+2:
+   dzm .int1
+1:
+"** 01-s1.pdf page 5
+   lac u.intflg
+   sza
+   jmp chkint i
+   -1
+   dac .insys
+   ion
+   isz chkint
+   jmp chkint i
+
diff --git a/scans/s2.s b/scans/s2.s
new file mode 100644
index 0000000..3847776
--- /dev/null
+++ b/scans/s2.s
@@ -0,0 +1,334 @@
+"** 01-s1.pdf page 7
+" s2
+
+.status:
+   jms arg
+   dac .+5
+   jms arg
+   dac .+6
+   lac u.cdir
+   jms namei; ..
+      jms error
+   jms namei; ..
+      jms error
+   jms iget
+   lac u.ac
+   and o17777
+   jms betwen; o10000; o17762
+      jms error
+   dac .+3
+   jms copy; inode; ..; 12
+   dac 9 i
+   jmp okexit
+
+.capt:
+   lac u.ac
+   dac u.dspbuf
+   jms movdsp
+   jmp sysexit
+
+.rele:
+   dzm u.dspbuf
+   law dspbuf
+   jms movdsp
+   jmp sysexit
+
+.chmod:
+   jms isown
+   lac u.ac
+   and o17
+   lmq
+   lac i.flags
+   and o777760
+   omq
+   dac i.flags
+   jms iput
+   jmp okexit
+
+.chown:
+   jms isown
+   lac u.ac
+   dac i.uid
+   jms iput
+   jmp okexit
+
+.getuid:
+   lac u.uid
+   dac u.ac
+   jmp sysexit
+
+.seek:
+   jms seektell
+   tad u.base
+"** 01-s1.pdf page 8
+   spa
+   jms error
+   lmq
+   lac f.flags
+   and d1
+   sna
+   jms 1f
+   lacq
+   jms betwen; d0; i.size
+      jms dacisize
+   jmp 2f
+1:
+   lacq
+   jms betwen; d0; i.size
+      lac i.size
+2:
+   dac f.badd
+   dac u.ac
+   jms fput
+   jmp sysexit
+
+.tell:
+   jms seektell
+   cma
+   tad d1
+   tad u.base
+   dac u.ac
+   jmp sysexit
+
+.link:
+   jms arg
+   dac 0f
+   jms arg
+   dac 1f
+   jms arg
+   dac 2f
+   lac d4
+   jms namei; 0:0
+      jms error
+   jms namei; 1:0
+      jms error
+   dac u.base
+   jms copy; 2:0; name; 4
+   lac u.cdir
+   jms namei; name
+      skp
+   jms error
+   lac d1
+   dac mode
+   jms access
+   jms dslot
+   lac u.base
+   jms iget
+   lac ii
+   dac d.i	"** ??
+   jms copy; name; d.name; 4
+   lac i.uniq
+   dac d.uniq
+   -1
+   tad i.nlks
+   dac i.nlks
+"** 01-s1.pdf page 9
+   jms iput
+   jms dput
+   jms okexit
+
+.unlink:
+   jms argname
+   dac u.base
+   lac d1
+   dac mode
+   jms access
+   dac d.i
+   jms dput
+   lac u.base
+   jms u.base
+   jms iget
+   isz i.nlks
+   jmp 1f
+   jms itrunc
+   dzm i.flags
+1:
+   jms iput
+   jmp sysexit
+
+.setuid:
+   lac u.uid
+   sma
+   jms error
+   lac u.ac
+   dac u.uid
+   jmp sysexit
+
+.rename:
+   jms arg
+   dac 0f
+   jms arg
+   dac 1f
+   lac u.cdir
+   jms namei; 0:0
+      jms error
+   lac d1
+   dac mode
+   jms access
+   jms copy; 1:0; d.name; 4
+   jmp okexit
+
+.time:
+   lac s.tim
+   dac u.ac
+   lac s.tim+1
+   dac u.mq
+   jmp sysexit
+
+.chdir:
+   jms argname
+   jms iget
+   lac i.flags
+   and o20
+   sna
+   jms error
+   lac ii
+   dac u.cdir
+"** 01-s1.pdf page 10
+   jmp okexit
+
+.open:
+   jms arg
+   dac 0f
+   jms arg
+   sza
+   lac d1
+   sna
+   lac d2
+   dac mode
+   lac u.cdir
+   jms namei; 0:0
+      jms error
+   jms iget
+   jms access
+   lac i.flags
+   and o20
+   sna
+   jmp open1
+   lac mode
+   and d1
+   sna
+   jmp open1
+   lac u.uid
+   sma
+   jms error
+   jmp open1
+
+.creat:
+   lac d1
+   dac mode
+   jms arg
+   dac .+2
+   jms copy; ..; name; 4
+   lac u.cdir
+   jms namei; name
+      jmp 1f
+   jms iget
+   jms access
+   lac i.flags
+   and o20
+   sna
+   jmp .+4
+   lac u.uid
+   sma
+   jms error
+   jms itrunc
+   cla
+   jms dacisize
+   jmp open1
+1:
+   jms access
+   lac u.ac
+   and o17
+   jms icreat
+open1:
+   jms fassign
+      jms error
+   jmp sysexit
+
+"** 01-s1.pdf page 11
+.close:
+   jms finac
+   dzm f.flags
+   jms fput
+   jmp sysexit
+
+.read:
+   jms arg
+   and o17777
+   dac u.base
+   jms arg
+   dac u.count
+   lac u.base
+   jms betwen; o10000; o17777
+      jms error
+   tad u.count
+   jms betwen; u.base; o17777
+      jms error
+   dac u.limit
+1:
+   jms finac
+   lac f.flags
+   and d1
+   sza
+   jms error
+   lac i.flags
+   and o40
+   sna
+   jmp 1f
+   iof
+   lac ii
+   tad swr
+   dac .+1
+   jmp .. i
+1:
+   lac u.base
+   dac 1f+1
+   lac u.count
+   dac 1f+2
+   lac f.badd
+1:
+   jms iread; ..; ..
+   jmp exitrw
+
+.write:
+   jms arg
+   and o17777
+   dac u.base
+   jms arg
+   dac u.count
+   tad u.base
+   jms betwen; u.base; o17777
+      jms error
+   dac u.limit
+   jms finac
+   lac f.flags
+   and d1
+   sna
+   jms error
+   lac i.flags
+   and o40
+"** 01-s1.pdf page 12
+   sna
+   jmp 1f
+   iof
+   lac ii
+   tad sww
+   dac .+1
+   jmp .. i
+1:
+   lac u.base
+   dac 1f+1
+   lac u.count
+   dac 1f+2
+   lac f.badd
+1:
+   jms iwrite; ..; ..
+
+exitrw:
+   dac u.ac
+   tad f.badd
+   dac f.badd
+   jms iput
+   jms fput
+    jmp sysexit
diff --git a/scans/s3.s b/scans/s3.s
new file mode 100644
index 0000000..742c0a3
--- /dev/null
+++ b/scans/s3.s
@@ -0,0 +1,355 @@
+"** 01-s1.pdf page 14
+" s3
+
+searchu: 0
+   lac searchu i
+   dac 9f+t+1
+   -mnproc
+   dac 9f+t
+   law ulist-1
+   dac 8
+1:
+   lac 8 i
+   dac lu
+   lac 8 i
+   dac lu+1
+   lac 8 i
+   dac lu+2
+   lac 8 i
+   dac lu+3
+   jms 9f+t+1 i
+   isz 9f+t
+   jmp 1b
+   isz searchu
+   jmp searchu i
+
+lookfor: 0
+   jms searchu; 1f
+   isz lookfor
+   isz lookfor
+   jmp lookfor i
+1: 0
+   lac lu
+   rtl; rtl; and o7
+   sad lookfor i
+   skp
+   jmp 1b i
+   -3
+   tad 8
+   and o17777
+   isz lookfor
+   jmp lookfor i
+
+.fork:
+   jms lookfor; 0 " not-user
+      skp
+      jms error
+   dac 9f+t
+   isz uniqpid
+   lac uniqpid
+   dac u.ac
+   law sysexit
+   dac u.swapret
+   lac o200000
+   tad u.ulistp i
+   dac u.ulistp i
+   jms dskswap; 07000
+   lac 9f+t
+   dac u.ulistp
+   lac o100000
+   xor u.ulistp i
+   dac u.ulistp i
+   lac u.pid
+"** 01-s1.pdf page 15
+   dac u.ac
+   lac uniqpid
+   dac u.pid
+   isz 9f+t
+   dac 9f+t i
+   isz u.rq+8
+   dzm u.intflg
+   jmp sysexit
+t= t+1
+
+badcal:
+   clon
+   -1
+   dac 7
+.save:
+   lac d1
+   jms iget
+   cla
+   jms iwrite; 4096; 4096
+   jms iwrite; userdata; 64
+   jms iput
+
+.exit:
+   lac u.dspbuf
+   sna
+   jmp .+3
+   law dspbuf
+   jms movdsp
+   jms awake
+   lac u.ulistp i
+   and o77777
+   dac u.ulistp i
+   isz u.ulistp
+   dzm u.ulistp i
+   jms swap
+
+.rmes:
+   jms awake
+   lac o100000
+   tad u.ulistp i
+   dac u.ulistp i
+   law 2
+   tad u.ulistp
+   dac 9f+t
+   -1
+   dac 9f+t i
+   jms swap
+   law 2
+   tad u.ulistp
+   dac 9f+t
+   lac 9f+t i
+   cma
+   dac u.ac
+   dzm 9f+t i
+   isz 9f+t i
+   lac 9f+t i
+   dac u.mq
+   dzm 9f+t i
+   jmp sysexit
+t = t+1
+
+"** 01-s1.pdf page 16
+.smes:
+   lac u.ac
+   sna spa
+   jms error
+   jms searchu; 1f
+   law 2
+   tad u.ulistp
+   dac 9f+t
+   dzm 9f+t i
+   jms error
+1: 0
+   lac lu+1
+   sad u.ac
+   skp
+   jmp 1b i
+   lac lu+2
+   sad dm1
+   jmp 1f
+   lac o100000
+   tad u.ulistp i
+   dac u.ulistp i
+   law 2
+   tad u.ulistp
+   dac 9f+t
+   lac u.ac
+   dac 9f+t i
+   jms swap
+   law 2
+   tad u.ulistp
+   dac 9f+t
+   dzm 9f+t i
+   jmp .smes
+1:
+   -3
+   tad 8
+   dac 9f+t
+   lac o700000
+   tad 9f+t i
+   dac 9f+t i
+   isz 9f+t
+   isz 9f+t
+   lac u.pid
+   cma
+   dac 9f+t i
+   isz 9f+t
+   lac u.mq
+   dac 9f+t i
+   jmp okexit
+t = t+1
+
+awake: 0
+   jms searchu; 1f
+   jmp awake i
+1: 0
+   lac u.pid
+   sad lu+2
+   skp
+   jmp 1b i
+   -3
+   tad 8
+   dac 9f+t
+"** 01-s1.pdf page 17
+   lac o700000
+   tad 9f+t i
+   dac 9f+t i
+   jmp 1b i
+t = t+1
+
+swr:
+sww:
+   jmp .-4 i
+   .halt; rttyi; rkbdi; rppti; .halt
+   .halt; wttyo; wdspo; wppto
+
+.halt: jms halt
+
+rttyi:
+   jms chkint1
+   lac d1
+   jms getchar
+      jmp 1f
+   and o177
+   jms betwen o101; o132
+   skp
+   tad o40
+   alss 9
+   jmp passone
+1:
+   jms sleep; sfiles+0
+   jms swap
+   jmp rttyi
+
+wttyo:
+   jms chkint1
+   jms forall
+   sna
+   jmp failr
+   lmq
+   lac sfiles+1
+   spa
+   jmp 1f
+   xor 0400000
+   dac sfiles+1
+   lacq
+   tls
+   sad o12
+   jms putcr
+   jmp failr
+1:
+   lacq
+   dac char
+   lac d2	"** written: d6 ttyout
+   jms putchar
+      skp
+   jmp failr
+   jms sleep; sfiles+1
+   jms swap
+   jmp wttyo
+
+rkbdi:
+   jms chkint1
+   lac d2
+   jms getchar
+"** 01-s1.pdf page 18
+      jmp 3f
+   lmq
+   and o155
+   sad o55
+   jmp 1f
+   lacq
+   and o137
+   sad o134
+   lacq
+   xor o40
+   lmq
+   jmp 2f
+1:
+   lacq
+   xor o20
+   lmq
+2:
+   lacq
+   dac u.limit
+1:
+   jms chkint1
+   lac u.limit
+   jms dspput
+      jmp 1f
+   jms sleep; sfiles+6
+   jms swap
+   jmp 1b
+1:
+   lac u.limit
+   alss 9
+   jmp passone
+3:
+   jms sleep; sfiles+2
+   jms swap
+   jmp rkbdi
+
+wdspo:
+   jms chkint1
+   jms forall
+   jms dspput
+      jmp failr
+   jms sleep; sfiles+6
+   jms swap
+   jmp wdspo
+
+
+rppti:
+   lac d4
+   jms getchar
+      jmp .+3
+   alss 9
+   jmp passone
+   lac sfiles+3
+   sma
+   rsa
+1:
+   jms sleep; sfiles+3
+   jms swap
+   jmp rppti
+"** 01-s1.pdf page 19
+
+wppto:
+   jms forall
+   sna
+   jmp failr
+   lmq
+   lac sfiles+4
+   spa
+   jmp 1f
+   xor o400000
+   dac sfiles+4
+   lacq
+   psa
+   jmp failr
+1:
+   lacq
+   dac char
+   lac d5
+   jms putchar
+      skp
+   jmp failr
+   jms sleep; sfiles+4
+   jms swap
+   jmp wppto
+
+passone:
+   sad o4000
+   jmp okexit
+   dac u.base i
+   lac d1
+   dac u.ac
+   jmp sysexit
+
+error: 0
+   -1
+   dac u.ac
+   jmp sysexit
+
+chkint1: 0
+   dzm .insys
+   jmp chkint
+      skp
+   jmp .save
+   -1
+   dac .insys
+   jmp chkint1 i
diff --git a/scans/s4.s b/scans/s4.s
new file mode 100644
index 0000000..e1e406f
--- /dev/null
+++ b/scans/s4.s
@@ -0,0 +1,343 @@
+"** 01-s1.pdf page 21
+" s4
+
+alloc: 0
+   -1
+   tad s.nfblks
+   spa
+   jmp 1f
+   dac s.nfblks
+   tad fblksp
+   jms laci
+   dac 9f+t
+   jms copyz; dskbuf; 64
+   lac 9f+t
+   jms dskwr
+   dzm .savblk
+   lac 9f+t
+   jmp alloc i
+1:
+   lac s.nxfblk
+   sna
+   jms halt " OUT OF DISK
+   dac s.fblks
+   jms dskrd
+   lac dskbuf
+   dac s.nxfblk
+   jms copy; dskbuf+1; s.fblks+1; 9
+   lac d10
+   dac s.nfblks
+   jmp alloc-1
+
+free: 0
+   lmq
+   lac s.nfblks
+   sad d10
+   jmp 1f
+   tad fblksp
+   dac 9f+t
+   lacq
+   dac 9f+t i
+   dzm .savblk
+   isz s.nfblks
+   jmp free i
+1:
+   lac s.nxfblk
+   dac dskbuf
+   jms copy; s.fblks+1; dskbuf+1; 9
+   lacq
+   dac s.nxfblk
+   jms dskwr
+   dzm .savblk
+   lac d1
+   dac s.nfblks
+   jmp free i
+t = t+1
+
+laci: 0
+   and o17777
+   tad o200000
+   dac .+1
+   lac ..
+   jmp laci i
+
+"** 01-s1.pdf page 22
+
+betwen: 0
+   lmq cmq
+   lac betwen i
+   dac 9f+t
+   lacq
+   tad 9f+t i
+   sma
+   jmp 1f
+   lac betwen i
+   dac 9f+t
+   isz betwen
+   lacq
+   tad 9f+t i
+   cma
+   spa sna
+1:
+   isz betwen
+   lacq
+   cma
+   jmp betwen i
+
+copy: 0
+   -1
+   tad copy i
+   dac 8
+   isz copy
+   -1
+   tad copy i
+   dac 9
+   isz copy
+   -1
+   tad copy i
+   cma
+   dac 9f+t
+   isz copy
+1:
+   lac 8 i
+   dac 9 i
+   isz 9f+t
+   jmp 1b
+   jmp copy i
+
+copyz: 0
+   -1
+   tad copyz i
+   dac 8
+   isz copyz
+   -1
+   tad copyz i
+   cma
+   dac 9f+t
+   isz copyz
+1:
+   dzm 8 i
+   isz 9f+t
+   jmp 1b
+   jmp copyz i
+t = t+1
+
+putchar: 0
+"** 01-s1.pdf page 23
+   dac 9f+t
+   cla
+   jms takeq
+      jmp putchar i
+   tad o40001
+   dac .+4
+   lac 9f+t
+   jms putq
+   lac char
+   lac q2+1 ..
+   isz putchar
+   jmp putchar i
+t = t+1
+
+getchar: 0
+   jms takeq
+      jmp i getchar
+   tad o200001
+   dac .+3
+   cla
+   jms putq
+   lac q2+1 ..
+   isz getchar
+   jmp i getchar
+
+takeq: 0
+   rcl
+   tad lacq1
+   dac .+7
+   tad o640000
+   dac .+17
+   tad d1
+   dac .+14
+   tad o500000
+   dac .+5
+   lac q1 ..
+   sna
+   jmp takeq i
+   dac lnkaddr
+   sad q1+1 ..
+   jmp .+5
+   tad o200000
+   dac .+1
+   lac q2 ..
+   jmp .+3
+   cla
+   dac q1+1 ..
+   dac q1 ..
+   isz takeq
+   lac lnkaddr
+   jmp i takeq
+
+putq: 0
+   rcl
+   tad dacq1
+   dac .+14
+   tad d1
+   dac .+13
+   tad o140000
+   dac .+1
+   lac q1-1 ..
+"** 01-s1.pdf page 24
+   sna
+   jmp .+6
+   tad o40000
+   dac .+2
+   lac lnkaddr
+   dac q2 ..
+   jmp .+3
+   lac lnkaddr
+   dac q1 ..
+   dac q1+1 ..
+   jmp putq i
+
+srcdbs: 0
+   lmq		"** written (printed chars obscured)
+   -ndskbs
+   dac 9f+t
+   law dskbs	"* -1 dac 8 written
+   dac 9f+t+1
+1:
+   lac 9f+t+2	"** crossed out
+   sad 9f+t+1	"** isz 8 written
+   jmp srcdbs i
+   law 65	"** crossed out
+   tad 9f+t+1	"** crossed out isz 8 written
+   isz 9f+t+1
+   isz 9f+t
+   jmp 1b
+   isz srcdbs
+   jmp srcdbs i
+
+collapse: 0
+   cla
+   jms srcdbs
+      jmp 1f
+   law dskbs
+   dac 9f+t+1	"** 9f+t+1 crossed out: 8 written in
+1:
+   lac 9f+t+1	"** 9f+t+1 crossed out: 8 written in
+   dac 0f+1
+   tad d2	"** crossed out: original obscured
+   dac 0f
+   cma
+   tad d1
+   tad edskbsp
+   and o17777
+   sna
+   jmp 0f+3
+   dac 0f+2
+   jms copy; 0:..; ..; ..
+   -65
+   tad edskbsp
+   dac 9f+t
+   tad d1
+   dac 0f
+   lac dskaddr
+   dac 9f+t i
+   jms copy; dskbuf; 0:..; 64
+   jmp collapse i
+
+dskrd: 0
+   jms betwen; d2; d7999
+
+"** 01-s1.pdf page 25
+      jms halt
+   sad dskaddr
+   jmp dskrd i
+   dac dskaddr
+   jms srcdbs
+      jmp 1f
+   lac dskaddr
+   jms dskio; 06000
+   jmp 1f
+1:
+   dzm 9f+t+1 i
+   law 1
+   tad 9f+t+1
+   dac .+2
+   jms copy; ..; dskbuf; 64
+2:
+   jms collapse
+   jmp dskrd i
+
+dskwr: 0
+   jms betwen; d2; d7999
+      jms halt
+   jms dskio; 07000
+   lac dskaddr
+   jms srcdbs
+      dzm 9f+t+1 i
+   jms collapse
+   jmp dskwr i
+t = t+3
+
+dskio: 0
+   dac dskaddr
+   cll; idiv; 80
+   dac 9f+t
+   lacq
+   idiv; 10
+   dac 9f+t+1
+   lls 22
+   xor 9f+t+1
+   als 8
+   dac 9f+t+1
+   lac 9f+t
+   idiv; 10
+   dac 9f+t
+   lls 22
+   xor 9f+t
+   jms dsktrans; -64; dskbuf; 9f+t; dskio
+   isz dskio
+   jmp dskio i
+t = t+1
+
+dsktrans: 0
+   -10
+   dac 9f+t
+1:
+   -1
+   tad dsktrans
+   dac 12
+"** 01-s1.pdf page 26
+   dscs
+   lac 12 i
+   dslw
+   lac 12 i
+   dslm
+   lac 12 i
+   jms laci
+   dsld
+   dzm .dskb
+   lac 12 i
+   jms laci
+   jms laci
+   dsls
+   lac .dskb
+   sna
+   jmp .-2
+   lac .dske
+   sma
+   jmp 12 i
+   isz 9f+t
+   jmp 1b
+   jms halt " 10 disk errors
+t = t+1
+
+halt: 0
+   isz 9f+t
+   jmp .-1
+   iof
+   hlt
+   jms copy; law; 4096; 4096
+   hlt; jmp .-1
+t = t+1
+
diff --git a/scans/s5.s b/scans/s5.s
new file mode 100644
index 0000000..8f12620
--- /dev/null
+++ b/scans/s5.s
@@ -0,0 +1,277 @@
+"** 01-s1.pdf page 28
+" s5
+
+dskswap: 0
+   cll; als 3
+   dac 9f+t
+   jms dsktrans; -64; userdata; 9f+t; dskswap
+   lac 9f+t
+   tad o20
+   dac 9f+t
+   jms dsktrans; -4096; 4096; 9f+t; dskswap
+   isz dskswap
+   jmp dskswap i
+
+t = t+1
+
+access: 0
+   lac i.flags
+   idunno	"** ???
+   lac u.uid
+   spa
+   jmp access i
+   sad i.uid
+   lrs 2
+   lacq
+   and mode
+   sza
+   jmp access i
+   jms error
+
+fassign: 0
+   -1
+   dac 9f+t
+1:
+   lac 9f+t
+   tad d10
+   jms fget
+      jms halt  " will not happen
+   lac f.flags
+   sma
+   jmp 1f
+   isz 9f+t
+   jmp 1b
+   jmp fassign i
+1:
+   lac mode
+   xor o400000
+   dac f.flags
+   lac ii
+   dac f.i
+   lac 9f+t
+   tad d10
+   dac u.ac
+   dzm f.badd
+   jms fput
+   isz fassign
+   jmp fassign i
+t = t+1
+
+fget: 0
+   jms betwen; d0; d9
+      jmp fget i
+   cll; mul; 3
+   lacq
+"** 01-s1.pdf page 29
+
+   tad ofilesp
+   dac 9f+t
+   dac .+2
+   jms copy; ..; fnode; 3
+   isz fget
+   jmp fget i
+
+fput: 0
+   lac 9f+t
+   dac .+3
+   jms copy; ; fnode; ..; 3
+   jmp fput i
+t = t+1
+
+forall: 0
+   lac u.base
+   sad u.limit
+   jmp 1f
+   lac u.base
+   ral
+   lac u.base i
+   snl
+   lrs 9
+   and o777
+   jmp forall i
+failr:
+   lac u.base
+   add o400000
+   dac u.base
+   jmp forall+1
+1:
+   lac u.count
+   dac u.ac
+   jmp sysexit
+
+sleep: 0
+   law ulist-1
+   dac 8
+   lac o200000
+   lmq		"** ???
+1:
+   lac u.ulistp i
+   sad 8 i
+   jmp 1f
+   isz 8
+   isz 8
+   isz 8
+   cla; lrs 1
+   jmp 1b
+1:
+   tad o100000
+   dac u.ulistp i
+   lac sleep i
+   dac 9f+t
+   lac 9f+t i
+   isz sleep
+   jmp sleep i
+t = t+1
+
+"** 01-s1.pdf page 30
+
+dslot: 0
+   dzm di
+   skp
+1:
+   isz di
+   lac di
+   jms dget
+   lac d.i
+   sza
+   jmp 1b
+   jmp dslot i
+
+icreat: 0
+   dac 9f+t
+   jms dslot
+   lac o20
+   dac ii
+1:
+   isz ii
+   lac ii
+   jms iget
+   lac i.flags
+   spa
+   jmp 1b
+   lac ii
+   dac d.i
+   jms copy; name; d.name; 4
+   isz s.uniq
+   lac s.uniq
+   dac d.uniq
+   dac i.uniq
+   lac 9f+t
+   xor o400000
+   dac i.flags
+   lac u.uid
+   dac u.uid
+   -1
+   dac i.nlks
+   dzm i.size
+   jms copyz; i.dskps; 7
+   jms iput
+   jms dput
+   jmp icreat i
+t = t+1
+
+dspput: 0
+   and o177
+   sna
+   jmp i dspput
+   sad o14
+   jmp 1f
+   lmq
+   sad o12
+   jmp dspnl
+   lac dsploc i
+   sad o400000
+   jmp dspleft
+   omq
+   dac dsploc i
+   isz dsploc
+   jmp i dspput
+
+"** 01-s1.pdf page 31
+
+1:
+   jms dspinit
+   jmp dspput i
+
+dspleft:
+   lac dsploc
+   sad edspbuf
+   jmp 1f
+   dac 8
+   lac o400000
+   dac 8 i
+   cla; llss 18+7
+   dac dsploc i
+   jmp dspput i
+
+dspnl: 0
+   lac dsplno
+   sad d33
+   jmp 1f
+   isz dsplno
+   jmp dspnl i
+1:
+   lac o2000
+   wbl
+   isz dspput
+   jmp dspput i
+
+dspinit: 0
+   lac dspbuf+3
+   dac dsploc
+   lac o300000
+   dac dspbuf+3
+   dzm dsplno
+   jmp dspinit i
+
+movdsp: 0
+   iof
+   caf
+   dac dspbufp
+   -1
+   dac .dspb
+   ion
+   jmp movdsp i
+
+arg: 0
+   lac u.rq+8 i
+   isz u.rq+8
+   jmp arg i
+
+argname: 0
+   jms arg
+   dac .+2
+   jms copy; ..; name; 4
+   lac u.cdir
+   jms namei; name
+      jms error
+   jmp argname i
+
+seektell: 0
+   jms arg
+   dac u.base
+
+"** 01-s1.pdf page 32
+   jms arg
+   dac u.limit
+   jms finac
+   lac u.limit
+   sna
+   jmp seektell i
+   sad d1
+   jmp .+3
+   lac i.size
+   jmp seektell i
+   lac f.badd
+   jmp seektell i
+
+isown: 0
+   jms argname
+   jms iget
+   lac u.uid
+   sma
+   sad i.uid
+   skp
+   jms error
+   jmp isown i
+
diff --git a/scans/s6.s b/scans/s6.s
new file mode 100644
index 0000000..e3855c8
--- /dev/null
+++ b/scans/s6.s
@@ -0,0 +1,341 @@
+"** 01-s1.pdf page 34
+" S6
+
+itrunc: 0
+   -7
+   dac 9f+t
+   lac idskpp
+   dac 9f+t+1
+1:
+   lac 9f+t+1 i
+   sna
+   jmp 4f
+   lac i.flags
+   and o200000
+   sna
+   jmp 3f
+   -64
+   dac 9f+t+2
+   lac dskbufp
+   dac 9f+t+3
+2:
+   lac 9f+t+1 i
+   jms dskrd
+   lac 9f+t+3 i
+   sza
+   jms free
+   isz 9f+t+3
+   isz 9f+t+3
+   jmp 2b
+3:
+   lac 9f+t+1 i
+   jms free
+   dzm 9f+t+1 i
+4:
+   isz 9f+t+1
+   isz 9f+t
+   jmp 1b
+   lac i.flags
+   and o577777
+   dac i.flags
+   jmp itrunc i
+t = t+4
+
+namei: 0
+   jms iget
+   -1
+   tad namei i
+   dac 9f+t+1
+   isz namei
+   lac i.flags
+   and o20
+   sna
+   jmp namei i
+   -8
+   tad i.size
+   cma
+   lrss 3
+   dac 9f+t
+   sna
+   jmp namei i
+   dzm di
+1:
+   lac di
+
+"** 01-s1.pdf page 35
+
+   jms dget
+   lac d.i
+   sna
+   jmp 2f
+   lac 9f+t+1
+   dac 8
+   lac d.name
+   sad 8 i
+   skp
+   jmp 2f
+   lac d.name+1
+   sad 8 i
+   skp
+   jmp 2f
+   lac d.name+2
+   sad 8 i
+   skp
+   jmp 2f
+   lac d.i
+   isz namei
+   jmp namei 1
+2:
+   isz di
+   isz 9f+t
+   jmp 1b
+   jmp namei i
+t = t+2
+
+iget: 0
+   dac ii
+   cll; idiv; 5
+   dac 9f+t
+   tad d2
+   dac 9f+i+1
+   jms dskrd
+   lac 9f+t
+   cll; mul; 12
+   lacq
+   tad dskbufp
+   dac 9f+t
+   dac .+2
+   jms copy; ..; inode; 12
+   jmp iget i
+
+iput: 0
+   lac 9f+t+1
+   jms dskrd
+   law inode-1
+   dac 8
+   -1
+   tad 9f+t
+   dac 9
+   -12
+   dac 9f+t+2
+1:
+   lac 8 i
+
+"** 01-s1.pdf page 36
+
+   sad 9 i
+   skp
+   jmp 2f
+   isz 9f+t+2
+   jmp 1b
+   jmp iput i
+2:
+   -1
+   tad 8
+   dac 8
+   -1
+   tad 9
+   dac 9
+1:
+   lac 8 i
+   dac 9 i
+   isz 9f+t+2
+   jmp 1b
+   lac 9f+t+1
+   jms dskwr
+   jmp iput i
+t = t+3
+
+dget: 0
+   dac di
+   alss 3
+   dac 9f+t
+   jms pget
+   dac 9f+t+1
+   jms dskrd
+   lac 9f+t
+   and o77
+   tad dskbufp
+   dac 9f+t+2
+   dac .+2
+   jms copy; ..; inode; 8
+   lac 9f+t
+   tad d8
+   jms betwen; d0; i.size
+      skp
+   jmp dget i
+   jms dacisize
+   dzm d.i
+   jmp dget i
+
+dput: 0
+   lac 9f+t+1
+   jms dskrd
+   lac 9f+t+2
+   dac .+3
+   jms copy; inode; ..; 8
+   lac 9f+t+1
+   jms dskwr
+   jmp dput i
+
+t = t+3	"** first t not there (hole from hole punch?)
+
+pget: 0
+   lrss 6
+   dac 9f+t
+   lac i.flags
+
+"** 01-s1.pdf page 37
+
+   and o200000
+   sza
+   jmp 2f
+   lac 9f+t
+   jms betwen; d0; d6
+      jmp 1f
+   tad idskpp
+   dac 9f+t
+   lac 9f+t i
+   sna
+   jms alloc
+   dac 9f+t i
+   jmp pget i
+1:
+   jms alloc
+   dac 9f+t+1
+   jms copy; i.dskps; dskbuf; 7
+   jms copyz; dskbuf+7; 64-7	"** NUMBER UNCLEAR
+   lac 9f+t+1
+   jms dskwr
+   lac 9f+t+1
+   dac i.dskps
+   jms copyz; i.dskps+1; 6
+   lac i.flags
+   xor o200000
+   dac i.flags
+2:
+   lac 9f+t
+   lrss 7
+   jms betwen; d0; d6
+      jms halt " file too big
+   tad idskpp
+   dac 9f+t+1
+   lac 9f+t+1 i
+   sna
+   jms alloc
+   dac 9f+t+1 i
+   dac 9f+t+2
+   jms dskrd
+   lac 9f+t
+   and o77
+   tad dskbufp
+   dac 9f+t+1
+   lac 9f+t+1 i
+   sza
+   jmp pget i
+   jms alloc
+   dac 9f+t
+   lac 9f+t+2
+   jms dskrd
+   lac 9f+t
+   jmp pget i
+t = t+3
+
+iwrite: 0
+   dac 9f+t
+   lac iwrite
+
+"** 01-s1.pdf page 38
+
+   dac iread
+   lac cskp
+   dac iwrite
+   jmp 1f
+
+iread: 0
+   dac 9f+t
+   lac cnop
+   dac iwrite
+1:
+   -1
+   tad iread i
+   dac 10
+   dac 11
+   isz iread
+   lac iread i
+   dac 9f+t+1
+   isz iread
+   lac o70000
+   xct iwrite
+   lac i.size
+   cma
+   tad 9f+t
+   cma
+   jms betwen; d0; 9f+t+1
+      lac 9f+t+1
+   dac 9f+t+2
+   cma
+   tad d1
+   sna
+   jmp iread i
+   dac 9f+t+1
+1:
+   lac 9f+t
+   jms pget
+   dac 9f+t+3
+   jms dskrd
+   lac 9f+t
+   and o77
+   tad dskbufp
+   tad dm1
+   xct iwrite
+   jmp .+3
+   dac 10
+cskp:
+   skp
+   dac 11
+2:
+   lac 11 i
+   dac 10 i
+   isz 9f+t
+   isz 9f+t+1
+   jmp 3f
+      xct iwrite
+      jmp 4f
+      lac 9f+t
+      jms betwen; d0; i.size
+         dac i.size
+      lac 9f+t+3
+   4:
+"** 01-s1.pdf page 38
+      lac 9f+t+2
+      jmp iread i
+
+3:
+   lac 9f+t
+   and o77
+   sza
+   jmp 2b
+   xct iwrite
+   jmp 1b
+   lac 9f+t+3
+   jms dskwr
+   jmp 1b
+t = t+4
+
+finac: 0
+   lac u.ac
+   jms fget
+      jms error
+   lac f.flags
+   sma
+   jms error
+   lac f.i
+   jms iget
+   jms finac i
+
+dacisize: 0
+   dac i.size
+   jms iput
+   lac i.size
+   jmp dacisize i
diff --git a/scans/s7.s b/scans/s7.s
new file mode 100644
index 0000000..6d12062
--- /dev/null
+++ b/scans/s7.s
@@ -0,0 +1,368 @@
+"** 01-s1.pdf page 41
+" s7
+
+pibreak:
+   dac .ac	"** CROSSED OUT....
+
+   dpsf
+   jmp 1f
+
+   dpcf
+   dprs
+   dac dpstat
+   sma ral
+   jmp 2f
+   dprc
+   dac dpchar
+   -1
+   dac dpread
+   lac dpstat
+   ral
+2:
+   sma
+   jmp piret
+   -1
+   dac dpwrite
+   jmp piret	"** END OF CROSSOUT
+
+1: clsf
+   jmp 1f
+
+   lpb
+   dac pbsflgs
+   isz s.tim+1
+   skp
+   isz s.tim
+   isz uquant
+	"** written: ttydelay -> ttyd1
+	"** written: ttyrestart -> ttyres1
+cnop:
+   nop
+   -1
+   dac 7
+   clon
+   lac ttydelay
+   spa
+   isz ttydelay
+   skp
+   jms ttyrestart
+   lac .dspb	"** START CROSSED OUT: written: lac tty
+   sna
+   jmp piret
+   isz .dsptm
+   skp
+   jmp dsprestart
+   sad d3
+   jmp piret
+   isz .dspb
+   jmp piret
+   jmp dsprestart "** END CROSSED OUT
+
+1: dssf
+   jmp 1f
+
+   -1
+   dac .dskb
+
+"** 01-s1.pdf page 42
+
+   dsrs
+   dac .dske
+   dscs
+   jmp piret
+
+1: lds		"** BEGIN CROSSED OUT
+   sma ral
+   jmp 1f
+   cdf
+   lac .dspb
+   sna
+   jmp piret
+   tad dm3
+   sna
+   jmp dsprestart
+   dac .dspb
+   jmp piret
+dsprestart:
+   lac d1
+   dac .dspb
+   lac dspbufp
+   beg		"** ???
+   -10
+   dac .dsptm
+   jmp piret
+
+1: sna ral
+   jmp .+3
+   racf
+   jmp piret
+   sma
+   jmp 1f
+   lda
+   dac .lpba
+   rlpd
+   jmp piret
+
+1: ksf
+   jmp 1f
+
+   lac ttydelay
+   sma
+   isz ttydelay
+   krb
+   dac char
+   sad o375
+   jmp intrp1
+   lac d1
+   jms putchar
+      dzm char
+   lac sfiles+0
+   jms wakeup
+   dac sfiles+0
+   lac char
+   sad o212
+   skp
+   jmp piret
+   lac sfiles+1
+   sma
+   xor o400000
+   dac sfiles+1
+
+"** 01-s1.pdf page 43
+
+   jms putcr
+   jms ttyrestart
+   jmp piret
+
+1: tsf
+   jmp 1f
+
+   tcf
+   jms ttyrestart
+   jmp piret
+
+ttyrestart: 0
+   lac ttydelay
+   spa
+   jmp ttyrestart i
+   lac nttychar
+   dzm nttychar
+   sza
+   jmp 3f
+   isz ttydelay
+   lac d2
+   jms getchar
+      jmp 2f
+3:
+   tls
+   sad o12
+   jms putcr
+   sad o15
+   skp
+   jmp ttyrestart i
+   lac ttydelay
+   tad o20
+   rcr
+   cma
+   dac ttydelay
+   jmp ttyrestart i
+2:
+   lac sfiles+1
+   jms wakeup
+   dac sfiles+1
+   jmp ttyrestart i	"** written arrow up 2 copies
+
+1: sck			"** BEGIN CROSSED OUT
+   jmp 1f
+
+   cck
+   lck
+   dac char
+   sad o33
+   jmp intrp2
+   lac d3
+   jms putchar
+      nop
+   lac sfiles+2
+   jms wakeup
+   dac sfiles+2
+   jmp piret
+
+1: rsf
+   jmp 1f
+
+
+"** 01-s1.pdf page 44
+
+   lac npptchar
+   sna
+   jmp .+5
+   dac char
+   rrb
+   dac npptchar
+   jmp .+3
+   rrb
+   dac char
+3:
+   lac char
+   sna
+   jmp 2f
+   lac d4
+   jms putchar
+      jmp 3f
+   lac char
+   sad d4
+   jmp 4f
+2:
+   lac npptchar
+   sna
+   jmp .+4
+   dac char
+   dzm npptchar
+   jmp 3b
+   rsa
+   lac sfiles+3
+   jms wakeup
+   xor o400000
+   dac sfiles+3
+   jmp piret
+3:
+   lac char
+   dac npptchar
+4:
+   lac sfiles+3
+   jms wakeup
+   dac sfiles+3
+   jmp piret
+
+1: psf
+   jmp 1f
+
+   pcf
+   lac d5
+   jms getchar
+   jmp .+3
+   psa
+   jmp piret
+   lac sfiles+4
+   jms wakeup
+   dac sfiles+4
+   jmp piret
+
+1: spb		"** BEGIN CROSSED OUT
+   jmp 1f
+
+   cpb
+   lpb
+   dac pbsflgs+1
+
+"** 01-s1.pdf page 45
+
+   and o2000
+   sna
+   jmp piret
+   jms dspinit
+   lac sfiles+6
+   jms wakeup
+   dac sfiles+6
+   cla
+   wbl
+   jmp piret	"** END CROSSED OUT
+
+1: crsf
+   jmp 1f
+
+   crrb
+   dac crchar
+   -1
+   dac crread
+   jmp piret
+
+1: crrb
+
+piret:
+   lac 0
+   ral
+   lac .ac
+   ion
+   jmp 0 i
+
+wakeup: 0
+   dac 9f+t
+   -mnproc
+   dac 9f+t+1
+   lac tadu
+   dac 2f
+   lac dacu
+   dac 2f+1
+1:
+   lac 9f+t
+   ral
+   dac 9f+t
+   sma
+   jmp 2f+2
+   lac o700000
+2: tad ..
+   dac ..
+   lac 2b
+   tad d4
+   dac 2b
+   lac 2b+1
+   tad d4
+   dac 2b+1
+   isz 9f+t+1
+   jmp 1b
+   cla
+   jmp wakeup i
+
+t = t+2
+
+putcr: 0
+   lac o15
+   dac nttychar
+
+"** 01-s1.pdf page 46
+
+   cla
+   jmp putcr i
+
+intrp1:
+   lac d5
+   dac .int1
+   lac d1
+   jms getchar
+      skp
+   jmp .-3
+   lac d2
+   jms getchar
+      skp
+   jmp .-3
+   lac sfiles+0
+   jms wakeup
+   dac sfiles+0
+   lac sfiles+1
+   jms wakeup
+   dac sfiles+1
+   jms chkint
+      jmp piret
+   jmp 1f
+intrp2:
+   lac d7
+   dac .int2
+   lac d3
+   jms getchar
+      skp
+   jmp .-3
+   lac sfiles+2
+   jms wakeup
+   dac sfiles+2
+   lac sfiles+6
+   jms wakeup
+   dac sfiles+6
+   jms chkint
+      jmp piret
+1:
+   lac 0
+   dac 020
+   lac .ac
+   jmp 021
diff --git a/scans/s8.s b/scans/s8.s
new file mode 100644
index 0000000..88ad5f4
--- /dev/null
+++ b/scans/s8.s
@@ -0,0 +1,213 @@
+"** 01-s1.pdf page 48
+
+" s8
+
+" manifests
+mnproc = 10
+dspbsz = 270
+ndskbs = 4
+
+" flags
+.insys: 0
+.int1: 0
+.int2: 0
+.ac: 0
+.savblk: 0
+.dsptm: 0
+.dskb: 0
+.dske: 0
+
+" pointers
+tadu: tad ulist
+dacu: dac ulist
+maxquant: 30
+ofilesp: u.ofiles
+idskpp: i.dskps
+dskbufp: dskbuf
+edspbuf: dspbuf+dspbsz
+fblksp: s.fblks
+dacq1: dac q1
+lacq1: lac q1
+q2p: q2
+
+" strings
+initf:
+   <i>n;<i>t;< > ;< > "
+
+" constants
+d0: 0
+d1: 1
+d2: 2
+d3: 3
+d4: 4
+d5: 5
+d6: 6
+d7: o7: 07
+d8: 8
+d9: 9
+o12: d10: 10
+o14: 014
+o15: 015
+o17: 017
+o20: 020
+o33: 033
+o40: 040
+o55: 055
+o77: 077
+d65:o101: 0101
+d33: 33
+o132: 0132
+o134: 0134
+o137: 0137
+o155: 0155
+o177: 0177
+"** 01-s1.pdf page 49
+o212: 0212
+o375: 0375
+o777: 0777
+o2000: 02000
+o4000: 04000
+d7999: 7999
+o10000: 010000
+o17762: 017762
+o17777: 017777
+o20001: 020001
+o40000: 040000
+o40001: 040001
+o70000: 070000
+o77777: 077777
+o100000: 0100000
+o140000: 0140000
+o200000: 0200000
+o200001: 0200001
+o300000: 0300000
+o400000: 0400000
+o500000: 0500000
+o577777: 0577777
+o600000: 0600000
+o640000: 0640000
+o700000: 0700000
+o777700: 0777700
+o777760: 0777760
+dm3: -3
+dm1: -1
+
+9: .=.+t
+c1: .=.+1
+q1: q2;q2+90
+   .=.+14
+q2:
+   .+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0
+   .+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0
+   .+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0
+   .+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0
+   .+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0
+dsploc: .=.+1
+dsplno: .=.+1
+dspbuf:
+   0065057;0147740;0160000
+   .=.+30
+coldentry:
+   dzm 0100 " not re-entrant
+   caf
+   ion
+   clon
+   law 3072
+   wcga
+   jms dspinit
+   law dspbuf
+   jms movdsp
+   cla
+   jms dskio; 06000
+   jms copy; dskbuf; sysdata; ulist-sysdata
+   lac d3
+   jms namei; initf
+      jms halt
+"** 01-s1.pdf page 50
+   jms iget
+   cla
+   jms iread; 4096; 4096
+   jmp 4096
+   . = dspbuf+dspbsz+3
+dskbuf = 07700
+dskbs: .=.+65+65+65+65
+edskbsp: .
+uquant: .=.+1
+dspbufp: .=.+1
+pbsflgs: .=.+2
+mode: .=.+1
+nttychar: .=.+1
+npptchar: .=.+1
+ttydelay: .=.+1
+name: .=.+4
+lnkaddr: .=.+1
+char: .=.+1
+dskaddr: .=.+1
+uniqpid: 1
+lu: .=.+4
+sfiles: .=.+10
+dpdata:
+   dpstat: .=.+1
+   dpread: .=.+1
+   dpwrite: .=.+1
+   dpchar: .=.+1
+dspdata:
+   .dspb: .=.+1
+   .lpba: .=.+1	"** 4 written on listing
+crdata:
+   crread: .=.+1
+   crchar: .=.+1
+sysdata:
+   s.nxfblk: .=.+1
+   s.nfblks: .=.+1
+   s.fblks: .=.+10
+   s.uniq: .=.+1
+   s.tim: .=.+2
+ulist:
+   0131000;1;0;0
+   0031040;0;0;0
+   0031100;0;0;0
+   0031140;0;0;0
+   0031200;0;0;0
+   0031240;0;0;0
+   0031300;0;0;0
+   0031340;0;0;0
+   0031400;0;0;0
+   0031440;0;0;0
+userdata:
+   u.ac: 0
+   u.mq: 0
+   u.rq: .=.+9
+   u.uid: -1
+   u.pid: 1
+   u.cdir: 3
+   u.ulistp: ulist
+   u.swapret: 0
+   u.base: 0
+   u.count: 0
+"** 01-s1.pdf page 51
+   u.limit: 0
+   u.ofiles: .=.+30
+   u.dspbuf: 0
+   u.intflg: 1
+      .=userdata+64
+ii: .=.+1
+inode:
+   i.flags: .=.+1
+   i.dskps: .=.+7
+   i.uid: .=.+1
+   i.nlks: .=.+1
+   i.size: .=.+1
+   i.uniq: .=.+1
+      .= inode+12
+di: .=.+1
+dnode:
+   d.i: .=.+1
+   d.name: .=.+4
+   d.uniq: .=.+1
+      . = dnode+8
+fnode:
+   f.flags: .=.+1
+   f.badd: .=.+1
+   f.i: 0
+
diff --git a/scans/s9.s b/scans/s9.s
new file mode 100644
index 0000000..b308170
--- /dev/null
+++ b/scans/s9.s
@@ -0,0 +1,117 @@
+"** 01-s1.pdf page 53
+" s9 -- cold boot
+
+. = coldentry+4
+
+" zero i-list
+
+   dzm ii
+   jms copyz; dskbuf; 64
+1:
+   lac ii
+   jms dskio; 0700
+   isz ii
+   -710
+   tad ii
+   jmp 1b
+
+" free rest of disk
+
+1:
+   lac ii
+   jms free
+   isz ii
+   -6400
+   tad ii
+   sza
+   jmp 1b
+
+" read in tapes
+
+   dzm ii
+1:
+   dzm sum
+   jms getw " count
+   sza
+   jmp .+3
+   hlt
+   jmp 1b " 0 count means pause
+   dac xx
+   isz ii
+   lac ii
+   jms iget
+   jms copyz; inode; 12
+   jms getw " flags
+   dac i.flags
+   -1
+   dac i.uid
+   jms getw " number links
+   dac i.nlks
+   -2
+   tad xx
+   dac i.size
+   lac ii
+   dac i.uniq
+   law 4096-1
+   dac 8
+   -1
+   tad i.size
+   cma
+   sna
+   jmp 3f
+   dac xx
+
+"** 01-s1.pdf page 54
+2:
+   jms getw
+   dac 8 i
+   isz xx
+   jmp 2b
+3:
+   lac sum
+   dac xx
+   jms getw " checksum
+   sad xx
+   skp
+   jms halt
+   lac i.size
+   dac .+4
+   cla
+   jms iwrite; 4096; ..
+   jms iput
+   cla
+   jms dskio
+
+
+
+; 07000	"** writing on listing
+   jmp 1b
+
+getw: 0
+   jms getc
+   alss 12
+   lmq
+   jms getc
+   omq
+   lmq
+   jms getc
+   omq
+   lmq
+   add sum
+   dac sum
+   lacq
+   jmp getw i
+
+getc: 0
+   iof
+   rsa
+   rsf
+   jmp .-1
+   rrb
+   sna
+   jmp getc+1
+   and o77
+   ion
+   jmp getc i
+xx: 0
+sum:  0
diff --git a/scans/sop.s b/scans/sop.s
new file mode 100644
index 0000000..22ca2a4
--- /dev/null
+++ b/scans/sop.s
@@ -0,0 +1,97 @@
+"** 01-s1.pdf page 62
+" sop
+
+dac = 0040000
+jms = 0100000
+dzm = 0140000
+lac = 0200000
+xor = 0240000
+add = 0300000
+tad = 0340000
+xct = 0400000
+isz = 0440000
+and = 0500000
+sad = 0540000
+jmp = 0600000
+nop = 0740000
+i = 020000
+law = 0760000
+cma = 0740001
+las = 0750004
+ral = 0740010
+rar = 0740020
+hlt = 0740040
+sma = 0740100
+sza = 0740200
+snl = 0740400
+skp = 0741000
+sna = 0741200
+szl = 0741400
+rtl = 0742010
+rtr = 0742020
+cil = 0744000
+rcl = 0744010
+rcr = 0744020
+cia = 0750000
+lrs = 0640500
+lrss = 0660500
+lls = 0640600
+llss = 0660600
+als = 0640700
+alss = 0660700
+mul = 0653323
+idiv = 0653323
+lacq = 0641002
+clq = 0650000
+omq = 0650002
+cmq = 0650004
+lmq = 0652000
+
+dscs = 0707141
+dslw = 0707124
+dslm = 0707142
+dsld = 0707104
+dsls = 0707144
+dssf = 0707121
+dsrs = 0707132
+
+iof = 0700002
+ion = 0700042
+caf = 0703302
+clon = 0700044
+clsf = 0700001
+
+"** 01-s1.pdf page 63
+clof = 0700004
+ksf = 0700301
+krb = 0700312
+tsf = 0700401
+tcf = 0700402
+tls = 0700406
+sck = 0704301
+cck = 0704304
+lck = 0704312
+rsf = 0700101
+rsa = 0700104
+rrb = 0700112
+psf = 0700201
+pcf = 0700202
+psa = 0700204
+cdf = 0700501
+lds = 0701052
+lda = 0701012
+wcga = 0704206
+raef = 0700742
+rlpd = 0700723
+beg = 0700547
+spb = 0704401
+cpb = 0704404
+lpb = 0704412
+wbl = 0704424
+dprs = 0704752
+dpsf = 0704741
+dpcf = 0704761
+dprc = 0704712
+crsf = 0706701
+crrb = 0706712
+
diff --git a/scans/sx.s b/scans/sx.s
new file mode 100644
index 0000000..6b08758
--- /dev/null
+++ b/scans/sx.s
@@ -0,0 +1,4 @@
+" For now, this stuff is defined so that
+" the assembler doesn't complain about it
+
+o7000: 07000
diff --git a/scans/trysys.s b/scans/trysys.s
new file mode 100644
index 0000000..db45d59
--- /dev/null
+++ b/scans/trysys.s
@@ -0,0 +1,40 @@
+"** 01-s1.pdf page 65
+" trysys
+
+   sys open; a.out; 0
+   spa
+   jmp error
+   sys read; buf; 3072
+   sad .-1
+   jmp error
+   iof
+   caf
+   cdf
+   clof
+   law buf
+   dac t1
+   dzm t2
+   -3072
+   dac c1
+1:
+   lac t1 i
+   dac r2 i
+   isz t1
+   isz r2
+   isz c1
+   jmp 1b
+   jmp 0100
+
+error:
+   lac d1
+   sys write; 1f; 1
+   sys exit
+1: 077012
+
+a.out:
+   <a.>;<ou><t 040; 040040
+t1: 0
+t2: 0
+c1: 0
+d1: 1
+buf:
diff --git a/tools/a7out b/tools/a7out
index ee77652..b349f35 100755
--- a/tools/a7out
+++ b/tools/a7out
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 #
-# A7out: user-mode simulator for PDP-7 Unix applications
+# a7out: user-mode simulator for PDP-7 Unix applications
 #
 # (c) 2016 Warren Toomey, GPL3
 #
@@ -11,7 +11,7 @@ use Data::Dumper;
 ### Global variables ###
 my $debug = 0;    # Debug flag
 my @Mem;          # 8K 18-bit words of main memory
-my @FD;		  # Array of open filehandles
+my @FD;           # Array of open filehandles
 
 # Registers
 my $PC = 0;       # Program counter
@@ -27,11 +27,14 @@ if ( ( @ARGV > 0 ) && ( $ARGV[0] eq "-d" ) ) {
 }
 
 # Check the arguments
-die("Usage: $0 [-d] a.outfile\n") if ( @ARGV != 1 );
+die("Usage: $0 [-d] a.outfile [arg1 arg2 ...]\n") if ( @ARGV < 1 );
 
 # Load the a.out file into memory
 # and simulate it
-load_code( $ARGV[0] );
+load_code( shift(@ARGV) );
+set_arguments(@ARGV);
+#dump_memory();
+#exit(0);
 simulate();
 exit(0);
 
@@ -47,6 +50,7 @@ sub load_code {
     # Set up two file open filehandles
     $FD[0] = \*STDIN;
     $FD[1] = \*STDOUT;
+    $FD[8] = \*STDERR;		# According to cat.s (uses d8 == 8)
 
     # Open up the file
     open( my $IN, "<", $filename ) || die("Unable to open $filename: $!\n");
@@ -67,6 +71,62 @@ sub load_code {
     close($IN);
 }
 
+### Copy the arguments into the PDP-7 memory space, and build
+### an array of pointers to these arguments. Build a pointer
+### at 017777 that points at the array.
+###
+### At the moment, this is NOT what PDP-7 Unix uses, but it's
+### a start and it will help us to grok the real thing.
+###
+### For now, assume abc, def and ghi are stored in memory.
+### The layout of the pointers and strings would be:
+###
+###    +-------+
+###    |       |
+###    | +-----|---------+
+###    | |     |         |
+###    | | +---|---------|---------+
+###    | | |   |         |         |
+###    | | |   V         V         V
+###   |o|o|o|0|<ab>|<c 0|<de>|<f 0|<gh>|<i 0|o|
+###    ^                                     |
+###    |                                     |
+###    +-------------------------------------+
+###    0 0 0 0  0    0    0    0    0    0   0
+###    1 1 1 1  1    1    1    1    1    1   1
+###    7 7 7 7  7    7    7    7    7    7   7
+###    7 7 7 7  7    7    7    7    7    7   7
+###    6 6 6 7  7    7    7    7    7    7   7
+###    5 6 7 0  1    2    3    4    5    6   7
+###
+sub set_arguments {
+  # No arguments, set the 017777 pointer to 017776 which is NULL
+  if (@ARGV==0) {
+    $Mem[ 017777 ] = 017776;
+    dprintf("No arguments, so NULL 017777 pointer\n");
+    return;
+  }
+
+  # Count the number of words to store each string and its pointer
+  my $wordcount=2;  # 2 as we count the NULL pointer at end of array
+  my $argcount= @ARGV;
+  foreach my $arg (@ARGV) {
+    # +1 before /2 to allow for the NUL character at end of string
+    # += +1 to include the pointer to the string
+    $wordcount += 1 + ( (length($arg) +1)/2);
+  }
+
+  my $arraybase= 017777 - $wordcount;
+  my $stringbase= $arraybase + $argcount + 1;	# include NULL pointer
+  $Mem[ 017777 ] = $arraybase;
+
+  # Now copy each string into memory and initialise the pointer
+  foreach my $arg (@ARGV) {
+    $Mem[$arraybase++]= $stringbase;
+    $stringbase= string2mem($arg, $stringbase);
+  }
+}
+
 ### Simulate the machine code loaded into memory
 sub simulate {
 
@@ -74,6 +134,8 @@ sub simulate {
     my %Oplist = (
         oct("004") => \&dac,
         oct("020") => \&lac,
+        oct("034") => \&tad,
+        oct("060") => \&jmp,
         oct("070") => \&iot,
         oct("074") => \&special,
     );
@@ -86,18 +148,19 @@ sub simulate {
         my $opcode      = ( $instruction >> 12 ) & 074;
         my $indirect    = ( $instruction >> 13 ) & 1;
         my $addr        = $instruction & 017777;
-        #printf( "PC %06o: instruction %08o, op %03o, ind %o, addr %06o\n",
-        #    $PC, $instruction, $opcode, $indirect, $addr )
-        #  if ($debug);
+
+	# Work out what any indirect address would be
+	my $indaddr= ($indirect) ? $Mem[$addr] & 017777 : $addr;
+        dprintf( "PC %06o: instr %06o, op %03o, ind %o, addr %06o ind %06o\n",
+            $PC, $instruction, $opcode, $indirect, $addr, $indaddr );
 
         # Simulate the instruction. Each subroutine updates the $PC
         if ( defined( $Oplist{$opcode} ) ) {
-            $Oplist{$opcode}->( $instruction, $indirect, $addr );
-        }
-        else {
-            printf( "Unknown instruction 0%o at location 0%o\n",
+            $Oplist{$opcode}->( $instruction, $addr, $indaddr );
+        } else {
+            printf( STDERR "Unknown instruction 0%o at location 0%o\n",
                 $instruction, $PC );
-            die("\n");
+            exit(1);
         }
     }
 }
@@ -105,34 +168,44 @@ sub simulate {
 # Debug code: dump memory contents
 sub dump_memory {
     foreach my $i ( 0 .. 017777 ) {
-        printf( "%06o: %08o\n", $i, $Mem[$i] ) if ( $Mem[$i] != 0 );
+        printf( STDERR "%06o: %06o\n", $i, $Mem[$i] ) if ( $Mem[$i] != 0 );
     }
 }
 
 # Load AC
 sub lac {
-    my ( $instruction, $indirect, $addr ) = @_;
-    printf( "PC %06o: lac %05o (value %08o) into AC\n",
-        $PC, $addr, $Mem[$addr] )
-      if ($debug);
-    $AC = ($indirect) ? $Mem[ $Mem[$addr] & 017777 ]: $Mem[$addr];
+    my ( $instruction, $addr, $indaddr ) = @_;
+    dprintf( "PC %06o: lac %05o (value %06o) into AC\n",
+        $PC, $indaddr, $Mem[$indaddr] );
+    $AC = $Mem[$indaddr];
     $PC++;
 }
 
 # Deposit AC
 sub dac {
-    my ( $instruction, $indirect, $addr ) = @_;
-    printf( "PC %06o: dac AC (value %08o) into %05o into AC\n",
-        $PC, $AC, $addr )
-      if ($debug);
-    if ($indirect) {
-      $Mem[ $Mem[$addr] & 017777 ] = $PC;
-    } else {
-      $Mem[$addr] = $AC;
-    }
+    my ( $instruction, $addr, $indaddr ) = @_;
+    dprintf( "PC %06o: dac AC (value %06o) into %05o\n",
+        $PC, $AC, $indaddr );
+    $Mem[$indaddr] = $AC;
     $PC++;
 }
 
+# Add to AC
+sub tad {
+    my ( $instruction, $addr, $indaddr ) = @_;
+    dprintf( "PC %06o: tac AC (value %06o) from addr %05o\n",
+        $PC, $AC, $indaddr );
+    $AC+= $Mem[$indaddr];
+    $PC++;
+}
+
+# Jump
+sub jmp {
+    my ( $instruction, $addr, $indaddr ) = @_;
+    dprintf( "PC %06o: jmp %06o\n", $PC, $indaddr );
+    $PC = $indaddr;
+}
+
 # Special instructions
 sub special {
     my $instruction = shift;
@@ -140,15 +213,33 @@ sub special {
     # Deal with each one in turn
     # hlt
     if ( $instruction == 0740040 ) {
-        printf( "PC %06o: program halted\n", $PC );
+        printf( STDERR "PC %06o: program halted\n", $PC );
         dump_memory() if ($debug);
         exit(1);
     }
+    if ( $instruction == 0741100 ) {    # spa: skip on positive AC
+        dprintf( "PC %06o: spa AC %06o\n", $PC, $AC );
+        # Because we are dealing with 18 bits, compare the range
+        $PC += ( ($AC >= 0) && ($AC < 0400000) ) ? 2 : 1;
+        return;
+    }
+    if ( $instruction == 0741200 ) {    # sna: skip on non-zero AC
+        dprintf( "PC %06o: sna AC %06o\n", $PC, $AC );
+        $PC += ( $AC != 0 ) ? 2 : 1;
+        return;
+    }
+    if ( $instruction == 0740200 ) {    # sza: skip on zero AC
+        dprintf( "PC %06o: sza AC %06o\n", $PC, $AC );
+        $PC += ( $AC == 0 ) ? 2 : 1;
+        return;
+    }
+    printf( STDERR "PC %06o: unknown instruction %06o\n", $PC, $instruction );
+    exit(1);
 }
 
 # I/O transfer: used for system calls
 sub iot {
-    my ( $instruction, $indirect, $addr ) = @_;
+    my ( $instruction, $addr, $indaddr ) = @_;
 
     # Syscalls that we can simulate
     my %Syscallist = (
@@ -163,190 +254,236 @@ sub iot {
     if ( defined( $Syscallist{$addr} ) ) {
         $Syscallist{$addr}->();
     } else {
-        printf( "PC %06o: Unknown syscall %d\n", $PC, $addr );
-        die("\n");
+        printf( STDERR "PC %06o: Unknown syscall %d\n", $PC, $addr );
+        exit(1);
     }
 }
 
 # Exit system call
 sub sys_exit {
-  printf("PC %06o: exit system call\n", $PC) if ($debug);
-  exit(0);
+    dprintf( "PC %06o: exit system call\n", $PC );
+    exit(0);
 }
 
 # Close system call
 sub sys_close {
-  # AC is the file descriptor
-  my $fd= $AC;
-  printf("PC %06o: close: closing fd %d\n", $PC, $fd) if ($debug);
 
-  # Bump up the PC
-  $PC += 1;
+    # AC is the file descriptor
+    my $fd = $AC;
+    dprintf( "PC %06o: close: closing fd %d\n", $PC, $fd );
 
-  # That filehandle is not open, set an error -1 in octal
-  if (!defined($FD[$fd])) {
-    print("close: fd $fd is not open\n") if ($debug);
-    $AC= 0777777; return;
-  }
-  close($FD[$fd]);
-  $FD[$fd]= undef;
-  $AC=0; return;
+    # Bump up the PC
+    $PC += 1;
+
+    # That filehandle is not open, set an error -1 in octal
+    if ( !defined( $FD[$fd] ) ) {
+        dprint( "close: fd $fd is not open\n");
+        $AC = 0777777;
+        return;
+    }
+    close( $FD[$fd] );
+    $FD[$fd] = undef;
+    $AC = 0;
+    return;
 }
 
 # Open system call
 sub sys_open {
-  # Open seems to have arguments: PC+1 has a pointer to the filename,
-  # PC+2 and PC+3 I don't know yet, probably read/write and mask?
-  # AC is the opened fd on success, or -1 on error
 
-  # Get the start address of the string
-  my $start= $Mem[$PC+1];
+    # Open seems to have arguments: PC+1 has a pointer to the filename,
+    # PC+2 and PC+3 I don't know yet, probably read/write and mask?
+    # AC is the opened fd on success, or -1 on error
 
-  # Bump up the PC
-  $PC += 4;
+    # Get the start address of the string
+    my $start = $Mem[ $PC + 1 ];
 
-  # Convert this to a sensible ASCII filename
-  my $filename= mem2string($start);
-  printf("PC %06o: open: file %s\n", $PC, $filename) if ($debug);
+    # Bump up the PC
+    $PC += 4;
 
-  # Open the file
-  if (open(my $FH, "<", $filename)) {
-    # Find a place in the @FD array to store this filehandle. 99 is arbitrary
-    my $fd;
-    foreach $fd (0 .. 99) {
-      if (!defined($FD[$fd])) {
-        $FD[$fd]= $FH; last;
-      }
+    # Convert this to a sensible ASCII filename
+    my $filename = mem2string($start);
+    dprintf( "PC %06o: open: file %s\n", $PC, $filename );
+
+    # Open the file
+    if ( open( my $FH, "<", $filename ) ) {
+
+       # Find a place in the @FD array to store this filehandle. 99 is arbitrary
+       foreach my $fd ( 0 .. 99 ) {
+            if ( !defined( $FD[$fd] ) ) {
+                $FD[$fd] = $FH;
+        	$AC = $fd;
+                last;
+            }
+        }
+        return;
+    } else {
+        # No filehandle, so it's an error
+        dprintf( "open failed: $!\n");
+        $AC = 0777777;
+        return;
     }
-    $AC=$fd; return;
-  } else {
-    # No filehandle, so it's an error
-    print("open failed: $!\n") if ($debug);
-    $AC= 0777777; return;
-  }
 }
 
 # Read system call
 sub sys_read {
-  # Read seems to have arguments: AC is the file descriptor, PC+1 is
-  # the pointer to the buffer and PC+2 is the number of words to read.
-  # Return the number of words read in AC on success, or -1 on error.
 
-  # Get the file descriptor, start address and end address
-  my $fd= $AC;
-  my $start= $Mem[$PC+1];
-  my $count= $Mem[$PC+2];
-  my $end= $start + $count -1;
-  printf("PC %06o: read: %d words from %o from fd %d\n", $PC, $count, $start, $fd) if ($debug);
+    # Read seems to have arguments: AC is the file descriptor, PC+1 is
+    # the pointer to the buffer and PC+2 is the number of words to read.
+    # Return the number of words read in AC on success, or -1 on error.
 
-  # Bump up the PC
-  $PC += 3;
+    # Get the file descriptor, start address and end address
+    my $fd    = $AC;
+    my $start = $Mem[ $PC + 1 ];
+    my $count = $Mem[ $PC + 2 ];
+    my $end   = ($start + $count - 1) & 017777;
+    die("sys_read: bad start/end addresses $start $end\n") if ($end < $start);
+    dprintf( "PC %06o: read: %d words into %o from fd %d\n",
+        $PC, $count, $start, $fd );
 
-  # That filehandle is not open, set an error -1 in octal
-  if (!defined($FD[$fd])) {
-    print("read: fd $fd is not open\n") if ($debug);
-    $AC= 0777777; return;
-  }
+    # Bump up the PC
+    $PC += 3;
 
-  # Read each word in
-  my $FH= $FD[$fd];
-  $count=0;
-  foreach my $addr ($start .. $end) {
-    # It's a terminal, so convert from ASCII
-    if (-t $FH) {
-      my $c1= getc($FH);
-      last if (!defined($c1));			# No character, leave the loop
-      my $c2= getc($FH) || "";			# No character, make it a NUL
-      $Mem[$addr]= (ord($c1) << 9) | ord($c2);	# Pack both into one word
-      $count++;
-    } else {
-      # otherwise (for now) read in one line and convert to octal
-      my $line= <$FH>;
-      chomp($line);
-      last if (!defined($line));		# No line, leave the loop
-      $Mem[$addr]= oct($line) & 0777777;
-      $count++;
+    # That filehandle is not open, set an error -1 in octal
+    if ( !defined( $FD[$fd] ) ) {
+        dprint( "read: fd $fd is not open\n");
+        $AC = 0777777;
+        return;
     }
-  }
-  # No error
-  $AC= $count; return;
+
+    # Read each word in
+    my $FH = $FD[$fd];
+    $count = 0;
+    foreach my $addr ( $start .. $end ) {
+
+        # It's a terminal, so convert from ASCII
+        if ( -t $FH ) {
+            my $c1 = getc($FH);
+            last if ( !defined($c1) );    # No character, leave the loop
+            my $c2 = getc($FH) || "";     # No character, make it a NUL
+            $Mem[$addr] =
+              ( ord($c1) << 9 ) | ord($c2);    # Pack both into one word
+            $count++;
+        } else {
+            # otherwise (for now) read in one line and convert to octal
+            my $line = <$FH>;
+            last if ( !defined($line) );       # No line, leave the loop
+            chomp($line);
+            $Mem[$addr] = oct($line) & 0777777;
+            $count++;
+        }
+    }
+
+    # No error
+    $AC = $count;
+    return;
 }
 
 # Write system call
 sub sys_write {
 
-  # Write seems to have arguments: AC is the file descriptor, PC+1 is
-  # the pointer to the buffer and PC+2 is the number of words to write
+    # Write seems to have arguments: AC is the file descriptor, PC+1 is
+    # the pointer to the buffer and PC+2 is the number of words to write
 
-  # Get the file descriptor, start address and end address
-  my $fd= $AC;
-  my $start= $Mem[$PC+1];
-  my $count= $Mem[$PC+2];
-  my $end= $start + $count -1;
-  printf("PC %06o: write: %d words from %o to fd %d\n", $PC, $count, $start, $fd) if ($debug);
+    # Get the file descriptor, start address and end address
+    my $fd    = $AC;
+    my $start = $Mem[ $PC + 1 ];
+    my $count = $Mem[ $PC + 2 ];
+    my $end   = ($start + $count - 1) & 017777;
+    die("sys_write: bad start/end addresses $start $end\n") if ($end < $start);
+    dprintf( "PC %06o: write: %d words from %o to fd %d\n",
+        $PC, $count, $start, $fd );
 
-  # Bump up the PC
-  $PC += 3;
+    # Bump up the PC
+    $PC += 3;
 
-  # That filehandle is not open, set an error -1 in octal
-  if (!defined($FD[$fd])) {
-    print("write: fd $fd is not open\n") if ($debug);
-    $AC= 0777777; return;
-  }
-
-  # Write each word out
-  my $FH= $FD[$fd];
-  foreach my $addr ($start .. $end) {
-    # It's a terminal, so convert to ASCII
-    # otherwise (for now) print in octal
-    if (-t $FH) {
-      print($FH word2ascii($Mem[$addr]));
-    } else {
-      printf($FH "%06o\n", $Mem[$addr]);
+    # That filehandle is not open, set an error -1 in octal
+    if ( !defined( $FD[$fd] ) ) {
+        dprint( "write: fd $fd is not open\n");
+        $AC = 0777777;
+        return;
     }
-  }
-  # No error
-  $AC= 0; return;
+
+    # Write each word out
+    my $FH = $FD[$fd];
+    foreach my $addr ( $start .. $end ) {
+
+        # It's a terminal, so convert to ASCII
+        # otherwise (for now) print in octal
+        if ( -t $FH ) {
+            print( $FH word2ascii( $Mem[$addr] ) );
+        } else {
+            printf( $FH "%06o\n", $Mem[$addr] );
+        }
+    }
+
+    # No error
+    $AC = 0;
+    return;
 }
 
 # Convert an 18-bit word into two ASCII characters and return them.
 # Don't return NUL characters
 sub word2ascii {
-  my $word= shift;
-  my $c1= ($word >> 9) & 0177;
-  my $c2= $word & 0177;
-  my $result= "";
-  $result .= chr($c1) if ($c1);
-  $result .= chr($c2) if ($c2);
-  return($result);
+    my $word   = shift;
+    my $c1     = ( $word >> 9 ) & 0177;
+    my $c2     = $word & 0177;
+    my $result = "";
+    $result .= chr($c1) if ($c1);
+    $result .= chr($c2) if ($c2);
+    return ($result);
 }
 
 # Given the address of a word in memory, interpret that location
 # and those following as a NUL-terminated ASCII string and return
 # a copy of this string
 sub mem2string {
-  my $addr= shift;
-  my $result= "";
+    my $addr   = shift;
+    my $result = "";
 
-  while (1) {
-    # Stop when the address leave the 8K word address space
-    return($result) if ($addr > 017777);
+    while (1) {
 
-    # Stop when the value there is zero
-    my $word= $Mem[$addr];
-    return($result) if ($word==0);
+        # Stop when the address leave the 8K word address space
+        return ($result) if ( $addr > 017777 );
 
-    # Get the top ASCII character, return if NUL
-    my $c1= ($word >> 9) & 0177;
-    return($result) if ($c1==0);
-    $result .= chr($c1);
+        # Stop when the value there is zero
+        my $word = $Mem[$addr];
+        return ($result) if ( $word == 0 );
 
-    # Get the bottom ASCII character, return if NUL
-    my $c2= $word & 0177;
-    return($result) if ($c2==0);
-    $result .= chr($c2);
+        # Get the top ASCII character, return if NUL
+        my $c1 = ( $word >> 9 ) & 0177;
+        return ($result) if ( $c1 == 0 );
+        $result .= chr($c1);
 
-    # Move up to the next address
-    $addr++;
-  }
+        # Get the bottom ASCII character, return if NUL
+        my $c2 = $word & 0177;
+        return ($result) if ( $c2 == 0 );
+        $result .= chr($c2);
+
+        # Move up to the next address
+        $addr++;
+    }
+}
+
+# Given a string and the address of a word in memory, copy
+# the string into memory starting at that address and NUL
+# terminate the string. Return the first address after the string.
+#
+# We will go off the end of the string: suppress warnings
+no warnings ('substr');
+sub string2mem {
+    my ($str, $base)= @_;
+
+    # <= length so we go off the end and insert a NUL
+    for (my $i=0; $i <= length($str); $i += 2) {
+      my $c1= substr($str, $i, 1) || "";
+      my $c2= substr($str, $i+1, 1) || "";
+      #printf("Saving %06o to %05o\n", (ord($c1) << 9 ) | ord($c2), $base);
+      $Mem[$base++]= (ord($c1) << 9 ) | ord($c2);
+    }
+    return($base);
+}
+
+# Print out debug messages
+sub dprintf {
+  printf( STDERR @_) if ($debug);
 }
diff --git a/tools/as7 b/tools/as7
index 1d235b0..433cfd2 100755
--- a/tools/as7
+++ b/tools/as7
@@ -21,6 +21,8 @@ my $origline;  # The current input line of code
 
 my $stage = 1; # Pass one or pass two
 my $debug = 0; # Run in debug mode
+my $errors = 0; # set to non-zero on error
+my %Undef;	# undefined symbols: only complain once
 
 ### Main program ###
 
@@ -87,13 +89,25 @@ for my $i ( 0 .. $#Mem ) {
     }
 }
 
-exit(0);
+exit($errors);
+
+my $file;			# global for error messages
+my $lineno;
+
+sub err {
+    my $msg = shift;
+    $errors = 1;		# exit status
+    print STDERR "$file:$lineno: $msg\n";
+    return 0;
+}
 
 # Open and parse the given file
 sub parse_file {
-    my $file = shift;
+    $file = shift;
     open( my $IN, "<", $file ) || die("Cannot read $file: $!\n");
+    $lineno = 0;
     while ( my $line = <$IN> ) {
+	$lineno++;
 
         # Lose the end of line and any leading/trailing whitespace
         # Discard any comments and preceding comment whitespace
@@ -116,7 +130,7 @@ sub parse_file {
             my $labelsect = $1;
             my $statement = $2;
 
-            #print(">$labelsect< >$statement<\n");
+	    #print(">$labelsect< >$statement<\n");
 
             # Split $labelsect into labels using the : character
             my @labellist = split( /:\s*/, $labelsect );
@@ -147,9 +161,9 @@ sub parse_label {
     }
 
     # It's a textual label, check if it's been defined before
-    die("Label $label defined multiple times\n")
-      if ( defined( $Label{$label} ) );
-
+    if ( defined( $Label{$label} ) ) {
+	err("Label $label defined multiple times\n") if ( $stage == 1 );
+    }
     # Otherwise, save its value
     $Label{$label} = $Var{'.'};
     #printf( "Set absolute label %s to 0%o\n", $label, $Label{$label} );
@@ -426,7 +440,11 @@ sub parse_expression {
         #print("Did a subtraction and got $diff\n");
         return ($diff);
     }
-    die("I have no idea what $expression is in pass two\n") if ( $stage == 2 );
+    if ( $stage == 2 ) {
+	err("undefined: $expression") unless (defined $Undef{$expression});
+	$Undef{$expression} = 1;
+    }
+    return 0;
 }
 
 # Add two expression together
@@ -463,18 +481,20 @@ sub find_relative_label {
     my $curlocation = $Var{'.'};
 
     # Error check: no labels at all
-    die("No relative labels\n") if ( !defined( $Rlabel{$label} ) );
+    if ( !defined( $Rlabel{$label} ) ) {
+	return err("relative label $label not defined\n");
+    }
 
     # Get the list of possible locations for this label
     my $locarray = $Rlabel{$label};
 
     # Error check: no locations
-    die("No relative labels\n") if ( @{$locarray} == 0 );
+    return err("No relative labels") if ( @{$locarray} == 0 );
 
     # Error check: forward but no next location, or backward but no previous
-    die("No forward label\n")
+    return err("No forward label $label")
       if ( ( $direction eq 'f' ) && ( $curlocation > $locarray->[-1] ) );
-    die("No backward label\n")
+    return err("No backward label $label")
       if ( ( $direction eq 'b' ) && ( $curlocation < $locarray->[0] ) );
 
     # Search forward for a location larger then the current one
diff --git a/tools/wktcat.s b/tools/wktcat.s
new file mode 100644
index 0000000..ef11a35
--- /dev/null
+++ b/tools/wktcat.s
@@ -0,0 +1,123 @@
+" Warren's cat program: cat [arg1 arg2 ...]
+"
+" Because the a7out simulator currently doesn't deal with ASCII files,
+" here is how you can test it:
+" ./as7 wktcat.s > a.out
+"
+" ./a7out a.out > z1
+" <type some lines and end in ctrl-D>
+"
+" ./a7out a.out z1 z1
+" <the text you typed in will be displayed twice>
+"
+" Also, the current coding is hideous and needs refactoring.
+" I'm still coming to grips with PDP-7 assembly code.
+
+
+main:
+   " Load the pointer pointer in 017777 to see if we have any arguments
+   lac 017777 i
+   sza			" No args, so copy stdin to stdout
+     jmp catfiles	" Yes args, so deal with them below
+
+" This section copies from standard input to standard output
+stdinout:
+   " Read five words into the buffer from stdin
+   " Five was chosen arbitrarily
+   lac d0
+   sys read; buf; 5
+   spa			" Skip if result was >= 0
+     jmp error		" Result was -ve, so error result
+   sna			" Skip if result was >0
+     jmp end		" Result was zero, so nothing left to read
+
+   " Save the count of words read in
+   dac 1f
+
+   " Write five words from the buffer to stdout
+   lac d1
+   sys write; buf; 1:0
+
+   " and loop back for more words to read
+   jmp stdinout
+
+" This section opens files, and copies their contents to standard output
+catfiles:
+   " We start with AC pointing to an argument. Save it at label 1f
+   dac name
+
+   " Open the file and get the fd into AC
+   sys open; name:0; 0; 0
+   spa
+     jmp badfile	" Bad fd, exit with an error message
+   dac fd		" Save the file descriptor
+
+fileloop:
+   " Read five words into the buffer from the input file
+   lac fd
+   sys read; buf; 5
+   spa			" Skip if result was >= 0
+     jmp error		" Result was -ve, so error result
+   sna			" Skip if result was >0
+     jmp fileend	" Result was zero, so nothing left to read
+
+   " Save the count of words read in
+   dac 1f
+
+   " Write five words from the buffer to stdout
+   lac d1
+   sys write; buf; 1:0
+
+   " and loop back for more words to read
+   jmp fileloop
+
+fileend:
+   " Close the open file descriptor
+   lac fd
+   sys close
+
+   " Load and increment the 017777 pointer
+   lac 017777
+   tad d1
+   dac 017777
+
+   " Load the pointer pointer in 017777 to see if we have any more arguments
+   lac 017777 i
+   sna			" No args, so end the program
+     jmp end
+   jmp catfiles		" Otherwise loop back to cat this file
+
+end:
+   " exit
+   sys exit
+
+
+" This code comes from the real cat.s
+badfile:
+   lac name		" Get the pointer to the filename
+   dac 1f		" Store it in 1f below
+   lac d8		" Load fd 8 which is stderr
+   sys write; 1:0; 4	" Write the name, max 4 words
+   lac d8		" Then write " ?\n"
+   sys write; 1f; 2
+   sys exit		" and exit
+
+1: 040; 077012
+
+
+error:
+   " Print an "err read" string and exit
+   lac d1
+   sys write; noreadstr; 5
+   sys exit
+
+noreadstr:
+   <er>;<r 040;<re>;<ad>;012000
+
+fd: 0		" fd of the open file
+d0: 0		" Constants 0 and 1
+d1: 1
+d8: 8		" stderr seems to have fd 8
+
+" Input buffer for read
+buf: 0; 0; 0; 0; 0