Improvements to BRK/IRQ handler.

2024-06-05 01:29:31 +00:00 · 2021-09-29 18:23:49 -04:00 · 2021-09-29 18:23:49 -04:00 · efb57d5c37
commit efb57d5c37
parent 3393d4847b
3 changed files with 9 additions and 8 deletions
--- a/applecorn.po
+++ b/applecorn.po
--- a/auxmem.chario.s
+++ b/auxmem.chario.s
@ -56,9 +56,6 @@ WRCHHND      PHA
             PHX
             PHY
 * TO DO Check any output redirections
-*            TSX
-*            LDA   $103,X
-*            PHA

             JSR   OUTCHAR
 * TO DO Check any printer output
--- a/auxmem.misc.s
+++ b/auxmem.misc.s
@ -382,22 +382,26 @@ GSBRKAUX    >>>   IENTAUX        ; IENTAUX does not do CLI
 IRQBRKHDLR  PHA
 * Mustn't enable IRQs within the IRQ handler
 * Do not use WRTMAIN/WRTAUX macros
+            BIT   $C014
            STA   $C004          ; Write to main memory
            STA   $45            ; $45=A for ProDOS IRQ handlers
+            BPL   :NOTAUX
            STA   $C005          ; Write to aux memory
-
-            TXA
+:NOTAUX     TXA
            PHA
            CLD
            TSX
-            LDA   $103,X         ; Get PSW from stack
+            INX                  ; Safe way to do LDA $103,X
+            INX
+            INX
+            LDA   $0100,X        ; Get PSW from stack
            AND   #$10
            BEQ   :IRQ           ; IRQ
            SEC
-            LDA   $0104,X
+            LDA   $0101,X
            SBC   #$01
            STA   FAULT
-            LDA   $0105,X
+            LDA   $0102,X
            SBC   #$00
            STA   FAULT+1
            PLA