From: Alan Cox <alan@linux.intel.com>
Date: Sat, 18 Aug 2018 19:16:37 +0000 (+0100)
Subject: sam: Fix scrolling
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=527a505d9531e8d2c796f901b9dc267eb6b60378;p=FUZIX.git

sam: Fix scrolling
---

diff --git a/Kernel/platform-sam/sam_vt.s b/Kernel/platform-sam/sam_vt.s
index e1292124..334852b2 100644
--- a/Kernel/platform-sam/sam_vt.s
+++ b/Kernel/platform-sam/sam_vt.s
@@ -66,9 +66,9 @@ _scroll_up:
 	call ___hard_di
 	push af
 	call map_video
-	ld hl,#128
+	ld hl,#1024
 	ld de,#0
-	ld bc,#24576-128
+	ld bc,#24576-1024
 ldir_pop:
 	ldir
 pop_unmap:
@@ -82,10 +82,9 @@ _scroll_down:
 	call ___hard_di
 	push af
 	call map_video
-	ld hl,#24576
-	ld de,#24576-128
-	ld b,d
-	ld c,e
+	ld hl,#24575-1024
+	ld de,#24575
+	ld bc,#24576
 	lddr
 	jr pop_unmap
 
@@ -111,6 +110,7 @@ _plot_char:
 	ld bc,#0x04FF		; it gets decremented by DJNZ while the FF
 				; ensures the ldi never decrements B
 plot_loop:
+	; FIXME: this trick doesn't work on the last row - need a better way
 	ldi			; copy expanded char
 	ldi
 	dec e