Bugfix in outmdm (output buffer flush)HEADmaster

1 files changed, 8 insertions, 7 deletions

diff --git a/cpxac.asm b/cpxac.asm
index f8763c8..0b15d21 100644
--- a/cpxac.asm
+++ b/cpxac.asm
@@ -707,7 +707,7 @@ outcon:
 outmdm:

 	push	hl

 	ld	hl,(outptr)

-	ld	(hl),e			;return buffered char

+	ld	(hl),e			;save char in buffer

 	inc	hl

 	ld	(outptr),hl

 	ld	a,(outcnt)

@@ -750,22 +750,23 @@ omf_2:
 	ld	a,2			;start write transaction

 	out	(VI2C_CTRL),a

 

-	ld	hl,outbuf+2

-	ld	(outptr),hl

+	ld	hl,outbuf+2		;buffer start

 	ld	a,(outcnt)

-	sub	c

+	sub	c			;buffer now empty?

 	ld	(outcnt),a

 	jr	z,omfex

 

-	push	de

-	ld	d,h

+	push	de			;no, shift remaining chars down

+	ld	d,h			;dest = buffer start

 	ld	e,l

 	ld	b,0

-	add	hl,bc

+	add	hl,bc			;src = buffer start + num chars last transmitted

 	ld	c,a

 	ldir

+	ex	de,hl

 	pop	de

 omfex:

+	ld	(outptr),hl

 	pop	bc

 	pop	hl

 	ret