From af3d4581d306f00c4a7f0aba62f9d79962a3ff79 Mon Sep 17 00:00:00 2001
From: Greg King <gregdk@users.sf.net>
Date: Sun, 30 May 2021 13:30:08 -0400
Subject: [PATCH] Moved Creativision's playsound() into a separate file.

It won't waste space in a cartridge if it isn't used.
---
 asminc/creativision.inc         | 47 ++++++++++++++++++---------------
 libsrc/creativision/playsound.s | 40 ++++++++++++++++++++++++++++
 libsrc/creativision/psg.s       | 43 +++---------------------------
 3 files changed, 69 insertions(+), 61 deletions(-)
 create mode 100644 libsrc/creativision/playsound.s

diff --git a/asminc/creativision.inc b/asminc/creativision.inc
index 49d55a342..a0259ecce 100644
--- a/asminc/creativision.inc
+++ b/asminc/creativision.inc
@@ -5,21 +5,21 @@
 ;** Screen
 SCREEN_ROWS             = 24
 SCREEN_COLS             = 32
-SCREEN_PTR              = $3A
-CURSOR_X                = $3C
-CURSOR_Y                = $3D
+SCREEN_PTR              := $3A
+CURSOR_X                := $3C
+CURSOR_Y                := $3D
 
 ;** VDP
-VDP_DATA_R              = $2000
-VDP_STATUS_R            = $2001
-VDP_DATA_W              = $3000
-VDP_CONTROL_W           = $3001
+VDP_DATA_R              := $2000
+VDP_STATUS_R            := $2001
+VDP_DATA_W              := $3000
+VDP_CONTROL_W           := $3001
 
 ;** PIA
-PIA0_DATA               = $1000
-PIA0_STATUS             = $1001
-PIA1_DATA               = $1002
-PIA1_STATUS             = $1003
+PIA0_DATA               := $1000
+PIA0_STATUS             := $1001
+PIA1_DATA               := $1002
+PIA1_STATUS             := $1003
 
 ;** General
 CH_VLINE                = 33
@@ -30,11 +30,11 @@ CH_LLCORNER             = 37
 CH_LRCORNER             = 38
 
 ;** I/O (Zero-page variables)
-ZP_KEYBOARD             = $10
-ZP_JOY0_DIR             = $11
-ZP_JOY1_DIR             = $13
-ZP_JOY0_BUTTONS         = $16
-ZP_JOY1_BUTTONS         = $17
+ZP_KEYBOARD             := $10
+ZP_JOY0_DIR             := $11
+ZP_JOY1_DIR             := $13
+ZP_JOY0_BUTTONS         := $16
+ZP_JOY1_BUTTONS         := $17
 
 ;** Joystick direction values (ZP_JOY0_DIR/ZP_JOY1_DIR)
 JOY_N                   = $49
@@ -54,8 +54,13 @@ JOY_WNW                 = $4C
 JOY_NW                  = $4B
 JOY_NNW                 = $4A
 
-;** BIOS
-BIOS_IRQ1_ADDR          = $FF3F
-BIOS_IRQ2_ADDR          = $FF52
-BIOS_NMI_RESET_ADDR     = $F808
-BIOS_WRITE_VDP_REG      = $FE1F
+;** BIOS routines
+BIOS_NMI_RESET_ADDR     := $F808
+BIOS_PLAY_TUNE1         := $FBD6
+BIOS_PLAY_SONG          := $FBED
+BIOS_PLAY_TUNE2         := $FCE6
+BIOS_WRITE_VDP_REG      := $FE1F
+BIOS_QUIET_PSG          := $FE54
+BIOS_POKE_PSG           := $FE77
+BIOS_IRQ1_ADDR          := $FF3F
+BIOS_IRQ2_ADDR          := $FF52
diff --git a/libsrc/creativision/playsound.s b/libsrc/creativision/playsound.s
new file mode 100644
index 000000000..55c7a3fed
--- /dev/null
+++ b/libsrc/creativision/playsound.s
@@ -0,0 +1,40 @@
+; void __fastcall__ bios_playsound (void *a, unsigned char b);
+
+
+        .export         _bios_playsound
+
+        .import         popax
+
+        .include        "creativision.inc"
+
+
+songptr :=      $00             ; Points to current tune data
+volptr  :=      $04             ; Points to current volume table
+
+
+;* Creativision Sound Player
+;* Based on BIOS song player.
+;*
+;* Pass a pointer to a set of note triples, terminated with a tempo byte;
+;* and pass the length of the triples and tempo (max 255).
+;*
+;* Note: tune data must be stored backwards.
+
+_bios_playsound:
+        php
+        pha                     ; Save tune length
+        sei
+
+        lda     #<$FCD5         ; BIOS decreasing-volume table
+        ldx     #>$FCD5
+        sta     volptr
+        stx     volptr+1
+
+        jsr     popax           ; Get tune array pointer
+        sta     songptr
+        stx     songptr+1
+
+        pla
+        tay
+        dey                     ; Point to tempo byte
+        jmp     BIOS_PLAY_SONG  ; Let BIOS do its thing
diff --git a/libsrc/creativision/psg.s b/libsrc/creativision/psg.s
index c84f92f43..ec878af31 100644
--- a/libsrc/creativision/psg.s
+++ b/libsrc/creativision/psg.s
@@ -1,27 +1,18 @@
 ; void __fastcall__ psg_outb (unsigned char b);
 ; void __fastcall__ psg_delay (unsigned char b);
-; void __fastcall__ bios_playsound (void *a, unsigned char b);
 ; void psg_silence (void);
 
 
         .export         _psg_outb, _psg_silence, _psg_delay
-        .export         _bios_playsound
-
-        .import         popax
 
         .include        "creativision.inc"
 
 
-songptr :=      $00             ; Points to current tune data
-volptr  :=      $04             ; Points to current volume table
-
-_psg_outb:
-        ;* Let BIOS output the value.
-        jmp     $FE77
+;* Let BIOS output the value.
+_psg_outb       := BIOS_POKE_PSG
 
 
-_psg_silence:
-        jmp     $FE54
+_psg_silence    := BIOS_QUIET_PSG
 
 
 _psg_delay:
@@ -37,31 +28,3 @@ l3:     sbc     #1
         dey
         bne     l1
         rts
-
-
-;* Creativision Sound Player
-;* Based on BIOS song player.
-;*
-;* Pass a pointer to a set of note triples, terminated with a tempo byte;
-;* and pass the length of the triples and tempo (max 255).
-;*
-;* Note: tune data must be stored backwards.
-
-_bios_playsound:
-        php
-        pha                     ; Save tune length
-        sei
-
-        lda     #<$FCD5         ; A BIOS volume table
-        ldx     #>$FCD5
-        sta     volptr
-        stx     volptr+1
-
-        jsr     popax           ; Get tune array pointer
-        sta     songptr
-        stx     songptr+1
-
-        pla
-        tay
-        dey                     ; Point to tempo byte
-        jmp     $FBED           ; Let BIOS do its thing