avoid A2FPGA detecting non-existent speech chip

2026-04-20 17:20:14 +00:00 · 2024-11-13 19:45:08 -08:00
parent 29bcc548c5
commit ed1ac60c8d
1 changed files with 5 additions and 0 deletions
@@ -119,6 +119,7 @@ GetMockingboardStuff
         sta   @mb_smc20 + 2
         sta   @mb_smc21 + 2
         sta   @mb_smc22 + 2
+         sta   @mb_smc23 + 2

         ; detect speech - SSI263

@@ -184,6 +185,10 @@ GetMockingboardStuff
         lda   #$3f                  ; stop
@mb_smc19
         sta   $c400                 ; orb, write phoneme & pitch
+         lda   #$10
+@mb_smc23
+         bit   $c40d                 ; ifr, check for cb1 interrupt flag
+         bne   @got_irq              ; work around A2FPGA bug that does not clear cb1

         ldx   #$D0                  ; wait ~120ms, stop takes 47ms
 -        lda   #$10