Fix stack screwup in ZipChip code.

2025-01-19 05:30:35 +00:00 · 2022-09-23 23:17:32 -04:00 · 2022-09-23 23:17:32 -04:00 · dc5faabd66
commit dc5faabd66
parent dc2a198ff1
2 changed files with 5 additions and 6 deletions
--- a/applecorn.po
+++ b/applecorn.po
--- a/auxmem.oscli.s
+++ b/auxmem.oscli.s
@ -762,8 +762,6 @@ FAST         LDA   #$80                      ; Apple IIgs
             STA   $C05C                     ; Ultrawarp fast
             JSR   UNLOCKZIP                 ; ZipChip
             STA   $C05B                     ; Enable
-             LDA   #$00                      ; Full speed
-             STA   $C05D
             JSR   LOCKZIP
             RTS

@ -775,14 +773,14 @@ SLOW         LDA   #$80                      ; Apple IIgs
             STZ   GSSPEED
             STA   $C05D                     ; Ultrawarp slow
             JSR   UNLOCKZIP                 ; ZipChip
-             STA   $C05B                     ; Enable
-             LDA   #$D0                      ; 1.0667MHz
-             STA   $C05D
+             STZ   $C05A                     ; Disable
             JSR   LOCKZIP
             RTS

 * Unlock ZipChip registers
-UNLOCKZIP    LDA   #$5A
+UNLOCKZIP    PHP
+             SEI                             ; Timing sensitive
+             LDA   #$5A
             STA   $C05A
             STA   $C05A
             STA   $C05A
@ -792,6 +790,7 @@ UNLOCKZIP    LDA   #$5A
 * Lock ZipChip registers
 LOCKZIP      LDA   #$A5
             STA   $C05A
+             PLP
             RTS