Add beep for apple2

2026-04-25 22:18:27 +00:00 · 2024-01-18 13:55:18 +01:00
parent 6c7106c9d9
commit 2ba176372e
6 changed files with 49 additions and 1 deletions
@@ -0,0 +1,20 @@
+;
+; Colin Leroy-Mira, 2024
+;
+; void beep(void)
+;
+
+        .export         _beep
+        .import         BELL
+
+        .include        "apple2.inc"
+
+        .segment        "LOWCODE"
+
+_beep:
+        lda     CH              ; Bell scrambles CH in 80col mode on IIgs, storing
+        pha                     ; it in OURCH and resetting CH to 0. Save it.
+        jsr     BELL
+        pla
+        sta     CH              ; Restore CH
+        rts
@@ -0,0 +1,20 @@
+;
+; Colin Leroy-Mira, 2024
+;
+; BELL routine
+;
+
+        .export         BELL
+
+        .include        "apple2.inc"
+
+        .segment        "LOWCODE"
+
+BELL:
+        ; Switch in ROM and call BELL
+        bit     $C082
+        jsr     $FF3A           ; BELL
+
+        ; Switch in LC bank 2 for R/O and return
+        bit     $C080
+        rts