Add original unix v6

2018-01-27 22:35:41 +09:00
commit 2c7099ee50
664 changed files with 106254 additions and 0 deletions
@@ -0,0 +1,32 @@
+/ getchar() -- get a character from input file fin
+
+.globl	_getchar
+.comm	_errno,2
+.comm	_fin,518.
+
+_getchar:
+	mov	r5,-(sp)
+	mov	sp,r5
+	dec	_fin+2
+	bge	1f
+	mov	$_fin+6,_fin+4
+	mov	_fin,r0
+	sys	read; _fin+6; 512.
+	bes	badret
+	tst	r0
+	beq	badret
+	dec	r0
+	mov	r0,_fin+2
+1:
+	clr	r0
+	bisb	*_fin+4,r0
+	inc	_fin+4
+	mov	(sp)+,r5
+	rts	pc
+
+badret:
+	mov	r0,_errno
+	clr	r0
+	clr	_fin+2
+	mov	(sp)+,r5
+	rts	pc