Fix HGR scrolling corruption with ISR #199

2022-12-21 20:35:59 -05:00 · 2022-12-21 20:35:59 -05:00 · 754271b618
parent e228883700
commit 754271b618
1 changed files with 3 additions and 0 deletions
--- a/mainmem.hgr.s
+++ b/mainmem.hgr.s
@ -146,6 +146,8 @@ DRAWCHAR    >>>   ENTMAIN

 * Copy text line A+1 to line A 
 HGRSCR1L    >>>   ENTMAIN
+            PHP                     ; Disable interrupts ..
+            SEI                     ; .. to prevent corruption while scrolling
            INC   MTXTWINRGT
            ASL                     ; Dest addr->A4L,A4H
            TAX
@ -177,6 +179,7 @@ DOHGRSCR1L  LDX   #$00
            INX
            CPX   #8                ; 8 pixel rows in character
            BNE   :L1
+            PLP                     ; Re-enable interrupts
            >>>   XF2AUX,HSCR1RET

 * Copy text line A to line A+1