Add original unix v6

source/as/as23.s

@@ -0,0 +1,165 @@
+/
+/
+
+/ a3 -- pdp-11 assembler pass 2
+
+assem:
+	jsr	pc,readop
+	cmp	r4,$5
+	beq	2f
+	cmp	r4,$'<
+	beq	2f
+	jsr	pc,checkeos
+		br eal1
+	mov	r4,-(sp)
+	cmp	(sp),$1
+	bne	1f
+	mov	$2,(sp)
+	jsr	pc,getw
+	mov	r4,numval
+1:
+	jsr	pc,readop
+	cmp	r4,$'=
+	beq	4f
+	cmp	r4,$':
+	beq	1f
+	mov	r4,savop
+	mov	(sp)+,r4
+2:
+	jsr	pc,opline
+dotmax:
+	tstb	passno
+	bne	eal1
+	movb	dotrel,r0
+	asl	r0
+	cmp	dot,txtsiz-4(r0)
+	blos	ealoop
+	mov	dot,txtsiz-4(r0)
+eal1:
+	jmp	ealoop
+1:
+	mov	(sp)+,r4
+	cmp	r4,$200
+	bhis	1f
+	cmp	r4,$2
+	beq	3f
+	jsr	r5,error; 'x
+	br	assem
+1:
+	tstb	passno
+	bne	2f
+	movb	(r4),r0
+	bic	$!37,r0
+	beq	5f
+	cmp	r0,$33
+	blt	6f
+	cmp	r0,$34
+	ble	5f
+6:
+	jsr	r5,error; 'm
+5:
+	bic	$37,(r4)
+	bis	dotrel,(r4)
+	mov	2(r4),brdelt
+	sub	dot,brdelt
+	mov	dot,2(r4)
+	br	assem
+2:
+	cmp	dot,2(r4)
+	beq	assem
+	jsr	r5,error; 'p
+	br	assem
+3:
+	mov	numval,r4
+	jsr	pc,fbadv
+	asl	r4
+	mov	curfb(r4),r0
+	movb	dotrel,(r0)
+	mov	2(r0),brdelt
+	sub	dot,brdelt
+	mov	dot,2(r0)
+	br	assem
+4:
+	jsr	pc,readop
+	jsr	pc,expres
+	mov	(sp)+,r1
+	cmp	r1,$symtab	/test for dot
+	bne	1f
+	bic	$40,r3
+	cmp	r3,dotrel	/ can't change relocation
+	bne	2f
+	cmp	r3,$4		/ bss
+	bne	3f
+	mov	r2,dot
+	br	dotmax
+3:
+	sub	dot,r2
+	bmi	2f
+	mov	r2,-(sp)
+3:
+	dec	(sp)
+	bmi	3f
+	clr	r2
+	mov	$1,r3
+	jsr	pc,outb
+	br	3b
+3:
+	tst	(sp)+
+	br	dotmax
+2:
+	jsr	r5,error; '.
+	br	ealoop
+1:
+	cmp	r3,$40
+	bne	1f
+	jsr	r5,error; 'r
+1:
+	bic	$37,(r1)
+	bic	$!37,r3
+	bne	1f
+	clr	r2
+1:
+	bisb	r3,(r1)
+	mov	r2,2(r1)
+
+ealoop:
+	cmp	r4,$'\n
+	beq	1f
+	cmp	r4,$'\e
+	bne	9f
+	rts	pc
+1:
+	inc	line
+9:
+	jmp	assem
+
+checkeos:
+	cmp	r4,$'\n
+	beq	1f
+	cmp	r4,$';
+	beq	1f
+	cmp	r4,$'\e
+	beq	1f
+	add	$2,(sp)
+1:
+	rts	pc
+
+fbadv:
+	asl	r4
+	mov	nxtfb(r4),r1
+	mov	r1,curfb(r4)
+	bne	1f
+	mov	fbbufp,r1
+	br	2f
+1:
+	add	$4,r1
+2:
+	cmpb	1(r1),r4
+	beq	1f
+	tst	(r1)
+	bpl	1b
+1:
+	mov	r1,nxtfb(r4)
+	asr	r4
+	rts	pc
+