phil
4b284c6bbe
Finally understand location 7 (incremented at 60Hz) setting it to -1 causes clock interrupt every jiffy Improve comments in dsktrans Clarify cnop/cskp usage in iread/iwrite code iwrite and iread have common code entry at iwrite save return address at iread and overwrites return address to "skp" inst entry at iread puts "nop" inst at iwrite "xct iwrite" skips on write entry
256 lines
6.6 KiB
ArmAsm
256 lines
6.6 KiB
ArmAsm
"** 01-s1.pdf page 48
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" s8
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" manifests
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mnproc = 10 " number of processes
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dspbsz = 270 " display buffer size
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ndskbs = 4 " number of buffers at dskbs
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" flags
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.insys: 0 " "in system"
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.int1: 0 " inode for user interrupt 1
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.int2: 0 " inode for user interrupt 2
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.ac: 0 " saved AC from Priotity Interrupt
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.savblk: 0 " set by system call, cleared by disk i/o
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.dsptm: 0 " display restart countdown (10 ticks)
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.dskb: 0 " set on disk interrupt
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.dske: 0 " status from disk interrupt
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" pointers
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tadu: tad ulist
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dacu: dac ulist
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maxquant: 30
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ofilesp: u.ofiles
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idskpp: i.dskps
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dskbufp: dskbuf
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edspbuf: dspbuf+dspbsz
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dspbufp3: dspbuf+3
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fblksp: s.fblks
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dacq1: dac q1
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lacq1: lac q1
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q2p: q2
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" strings
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initf:
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<in>; <it>; 040040; 040040 " was <i>n;<i>t;< > ;< > but as.s unhappy!
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" constants
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d0: 0
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d1: 1
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d2: 2
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d3: 3
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d4: 4
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d5: 5
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d6: 6
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d7: o7: 07
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d8: 8
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d9: 9
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o12: d10: 10
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o14: 014
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o15: 015
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o17: 017
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o20: 020
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o33: 033
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o40: 040
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o55: 055
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o77: 077
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d65:o101: 0101
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d33: 33
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o132: 0132
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o134: 0134
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o137: 0137
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o155: 0155
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o177: 0177
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"** 01-s1.pdf page 49
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o212: 0212
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o375: 0375
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o777: 0777
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o2000: 02000
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o4000: 04000
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d7999: 7999
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o10000: 010000
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o17762: 017762
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o17777: 017777
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o20001: 020001
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o40000: 040000
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o40001: 040001
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o70000: 070000
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o77777: 077777
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o100000: 0100000
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o140000: 0140000
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o200000: 0200000
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o200001: 0200001
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o300000: 0300000
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o400000: 0400000
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o500000: 0500000
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o577777: 0577777
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o600000: 0600000
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o640000: 0640000
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o700000: 0700000
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o777700: 0777700
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o777760: 0777760
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dm3: -3
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dm1: -1
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9: .=.+t " per-routine temp variables
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c1: .=.+1 " not used?
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" character queues (two words each, head and tail pointers?)
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" 0: free list
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" 1: tty input
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" 2: tty output
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" 3: display keyboard
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" 4: paper tape reader
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" 5: paper tape punch
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q1: q2;q2+98 " queue element free list
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.=.+14 " room for 7 queues (5 used)
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q2: " queue elements (and two words padding??)
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.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0
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.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0
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.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0
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.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0
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.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;.+2;0;0;0
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dsploc: .=.+1 " pointer into dspbuf
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dsplno: .=.+1 " display current line number
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dspbuf:
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0065057;0147740;0160000 " display commands: see 03-scope.pdf pg 20
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" PARAM: clear blink, clear light pen, scale=1, intensity=3
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" X-Y: invisible, no delay, Y=01740 (992)
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" X-Y: invisible, settling delay, X=0
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.=.+30
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" Kernel startup (reused for display buffer)
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coldentry:
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dzm 0100 " not re-entrant
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caf " clear all flags
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ion " enable interrupts
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clon " clear clock overflow flag
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law 3072 " initialize display....
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wcga
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jms dspinit
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law dspbuf " set display buffer to default
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jms movdsp
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cla " read system block from disk
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jms dskio; 06000
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jms copy; dskbuf; sysdata; ulist-sysdata " copy to system data
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lac d3 " look for "init" in default directory
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jms namei; initf
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jms halt
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"** 01-s1.pdf page 50
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jms iget
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cla
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jms iread; 4096; 4096 " read in "init"
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jmp 4096 " start process 1
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. = dspbuf+dspbsz+3
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dskbuf = 07700
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dskbs: .=.+65+65+65+65 " ndskbs buffers (block number + block)
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edskbsp: .
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uquant: .=.+1 " number of ticks user has been running
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dspbufp: .=.+1 " pointer to display buffer
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pbsflgs: .=.+2 " buttons on last tick, last button interrupt
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mode: .=.+1 " user access mode: 1 for write, 2 for read
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nttychar: .=.+1 " CR to send next, or zero
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npptchar: .=.+1 " saved PTR char
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ttydelay: .=.+1 " delay count for TTY output
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name: .=.+4 " file name for current sys call
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lnkaddr: .=.+1 " temp for character queue routines
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char: .=.+1 " current char: temp for PI
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dskaddr: .=.+1 " number of block in dskbuf
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uniqpid: 1 " pid generator
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lu: .=.+4 " user (process) table entry copy
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sfiles: .=.+10 " wait addresses for special files
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" (bit vectors of waiting processes?)
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" bit zero (MSB) is special, bit 1 first ulist entry, ....
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" offsets: 0: ttyin, 1: ttyout, 2: keyboard,
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" 3: ptr, 4: ptp, 6: display
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dpdata: " dataphone data
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dpstat: .=.+1
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dpread: .=.+1
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dpwrite: .=.+1
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dpchar: .=.+1
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dspdata: " display data
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.dspb: .=.+1
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.lpba: .=.+1 "** 4 written on listing
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crdata: " card reader data
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crread: .=.+1
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crchar: .=.+1
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sysdata: " system data 64 words saved to disk
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s.nxfblk: .=.+1 " pointer to next free block??
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s.nfblks: .=.+1 " number of free blocks (in fblks?)
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s.fblks: .=.+10 " cached free block numbers
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s.uniq: .=.+1 " next unique value
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s.tim: .=.+2 " (up?)time in 60Hz ticks (low, high)
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" user (process) table
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" first word
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" bits 0:2 -- status
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" 0: free slot
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" 1: in/ready
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" 2: in/notready
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" 3: out/ready
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" 4: out/notready??
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" bits 3:17 -- disk swap address/8
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" second word: process pid
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" third word: smes/rmes status:
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" 0: not waiting
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" -1: this process waiting (rmes)
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" other: complement of sender pid
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" fourth word: smes message
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ulist:
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0131000;1;0;0
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0031040;0;0;0
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0031100;0;0;0
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0031140;0;0;0
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0031200;0;0;0
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0031240;0;0;0
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0031300;0;0;0
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0031340;0;0;0
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0031400;0;0;0
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0031440;0;0;0
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userdata: " "ustruct" (swappable)
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u.ac: 0 " user AC
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u.mq: 0 " user MQ
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u.rq: .=.+9 " user 010-017, user PC
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u.uid: -1 " user id
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u.pid: 1 " process id
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u.cdir: 3 " connected directory (inode number?)
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u.ulistp: ulist " pointer to process table entry
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u.swapret: 0 " kernel routine to resume at after swap in
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u.base: 0 " start of user buffer
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u.count: 0 " size of user buffer
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"** 01-s1.pdf page 51
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u.limit: 0 " end of user buffer
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u.ofiles: .=.+30 " open files (10 "fnode" entries)
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u.dspbuf: 0
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u.intflg: 1
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.=userdata+64
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ii: .=.+1 " The current i-node number stored in inode
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inode: " disk inode in memory:
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i.flags: .=.+1 " inode flags
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" 400000 in use
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" 200000 large file
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" 000040 special device (indicated by inum)
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" 000020 directory
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" 000010 owner read
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" 000004 owner write
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" 000002 world read
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" 000001 world write
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i.dskps: .=.+7 " disk block numbers (indirect if "large file")
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i.uid: .=.+1 " owner
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i.nlks: .=.+1 " link count (negative)
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i.size: .=.+1 " size (in words)
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i.uniq: .=.+1 " unique number
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.= inode+12
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di: .=.+1 " directory index
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dnode: " directory entry:
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d.i: .=.+1 " inode number
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d.name: .=.+4 " name (space padded)
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d.uniq: .=.+1 " unique number from directory inode
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. = dnode+8
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fnode: " open file entry (copied from u.ofiles)
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f.flags: .=.+1 " see below
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f.badd: .=.+1 " offset
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f.i: 0 " file i-number
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" f.flags:
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" 400000 in use
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" 000002 read
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" 000001 write
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