Assemble psych and include it in the build. (#232)

Psych was added to the build system. It requires fops.s
for maths. Two notable things need to be fixed to make it
assemble:

 * d1 must be defined, presumably to a 1 following the
   patterns of other decimal numbers.

 * variable xx must be renamed so it doesn't clash with
   the xx instruction mnemonic used by the perl cross assembler.

build/Makefile

@@ -133,6 +133,7 @@ cmd:	dirs \
 	$(BINDIR)/moo \
 	$(BINDIR)/nm \
 	$(BINDIR)/p \
+	$(BINDIR)/psych \
 	$(BINDIR)/rm \
 	$(BINDIR)/rn \
 	$(BINDIR)/roff \
@@ -227,6 +228,10 @@ P=$(CMDSRC)/p1.s $(CMDSRC)/p2.s $(CMDSRC)/p3.s $(CMDSRC)/p4.s $(CMDSRC)/p5.s
 $(BINDIR)/p: $(P)
 	$(AS) $(ASARGS) -o $(BINDIR)/p $(P)
 
+PSYCH=$(CMDSRC)/psych.s $(CMDSRC)/fop.s
+$(BINDIR)/psych: $(PSYCH)
+	$(AS) $(ASARGS) -o $(BINDIR)/psych $(PSYCH)
+
 $(BINDIR)/rm: $(CMDSRC)/rm.s
 	$(AS) $(ASARGS) -o $(BINDIR)/rm $(CMDSRC)/rm.s
 

build/proto

@@ -50,6 +50,7 @@ dd           drwr- -1 4
         nm       frwr- -1 bin/nm
         od       frwr- -1 bin/od
         p        frwr- -1 bin/p
+        psych    frwr- -1 bin/psych
         rm       frwr- -1 bin/rm
         rn       frwr- -1 bin/rn
         roff     frwr- -1 bin/roff

src/cmd/psych.s

@@ -22,7 +22,7 @@ restart:
    fst; z		"[   z = z + g						- scan markup]
    fst; oldx		"[   g = -g * fact					- scan markup]
    fst; oldy		"[   fact = 1 / fact					- scan markup]
-   lac o400000		"[   xx = 500. * d * sin(b + pi/2)			- scan markup]
+   lac o400000		"[   exex = 500. * d * sin(b + pi/2)			- scan markup]
    dac i 11		"[   ni()						- scan markup]
    dac i 11		"[   yy = 500. * d * sin(b)				- scan markup]
    lac setx		"[   ni()						- scan markup]
@@ -51,7 +51,7 @@ loop:
    sin
    fmp; d
    fmp; fp500
-   fst; xx
+   fst; exex
    jms in
    jmp done
    fld; b
@@ -67,7 +67,7 @@ loop:
    dac i 11
    fld; oldx
    fng
-   fad; xx
+   fad; exex
    fix
    spa
    xor o775777
@@ -81,7 +81,7 @@ loop:
    xor o775777
    tad vecy
    dac i 10
-   fld; xx
+   fld; exex
    fst; oldx
    fld; yy
    fst; oldy
@@ -261,7 +261,7 @@ release: 0
 
 char: 0
 stick: 0
-xx: 0; 0; 0
+exex: 0; 0; 0
 oldx: 0; 0; 0
 yy: 0; 0; 0
 oldy: 0;0 0; 0
@@ -277,6 +277,7 @@ o177777: 0177777
 o12000: 012000
 o61000: 061000
 om60: -060
+d1: 1
 d13: 13
 d500: 500
 o141000: 0141000