Add original unix v6

source/tmg/tmgb/px.s

@@ -0,0 +1,38 @@
+f = r5
+i = r3
+.globl j,n
+.globl iget,jget
+.globl succ,fail
+.globl .px,.pxs
+
+.pxs:
+	mov	i,r0
+	tst	(i)+
+	br	1f
+.px:
+	jsr	pc,iget
+1:
+	inc	litc
+	mov	n(f),-(sp)
+	mov	j(f),-(sp)
+	mov	r0,-(sp)
+2:
+	tstb	*(sp)
+	beq	2f
+	jsr	pc,jget
+	cmpb	r0,*(sp)
+	beq	1f
+	tst	(sp)+
+	mov	(sp)+,j(f)
+	mov	(sp)+,n(f)
+	jmp	fail
+1:
+	clr	n(f)
+	inc	(sp)
+	inc	j(f)
+	br 	2b
+2:
+	cmp	(sp)+,(sp)+
+	mov	(sp)+,n(f)
+	jmp	succ
+litc:	0