Document fix for CH/OURCH bug

2021-11-08 20:59:50 -08:00 · 2021-11-08 20:59:50 -08:00 · 0ab94dd62b
parent 3ff457ce35
commit 0ab94dd62b
2 changed files with 10 additions and 3 deletions
--- a/ace2000_c300_cfff.s
+++ b/ace2000_c300_cfff.s
@ -203,8 +203,12 @@ LC35B:  php
        lsr     WNDWDTH
        asl     WNDWDTH
        sta     SET80COL
+
+        ;; NOTE: In ACE 500 ROM, the below is patched to
+        ;; address the CH/OURCH issue.
        lda     OURCH
        sta     CH
+
 LC36D:  plp
        pla
        bcs     LC376
--- a/ace500_c300_cfff.s
+++ b/ace500_c300_cfff.s
@ -1280,10 +1280,13 @@ LC9B4:  bit     RD80VID
        lsr     WNDWDTH
        asl     WNDWDTH
        sta     SET80COL
-LC9C0:  lda     CH
+
+        ;; This is CH fix described in source fragment below!
+LC9C0:  lda     CH              ; HAVE THEY CHANGED COL?
        cmp     XCOORD
-        bne     LC9CA
-        lda     OURCH
+        bne     LC9CA           ; YES - USE THEIRS
+        lda     OURCH           ; ELSE USE OURS (THEY MIGHT HAVE
+                                ; CHANGED THIS TOO)
 LC9CA:  sta     CH
 LC9CC:  rts