Add Arcade Pacman hardware

presets/pacman/pacman_common.c

@@ -0,0 +1,269 @@
+/*
+ * Shared Pac-Man hardware helpers for 8bitworkshop demos.
+ *
+ * Owns the reset/IRQ CRT at absolute 0x0000 (_HEADER). Real Pac-Man VBLANK
+ * is a maskable IRQ (IM2), not NMI — same as MAME. Optional per-game work
+ * goes through pac_vblank_hook (set before pac_irq_enable()).
+ *
+ * Game demos must NOT define start(); call pac_irq_enable() from main.
+ */
+#pragma opt_code_speed
+#include "pacman_common.h"
+
+/*
+ * Absolute CRT0 @ 0x0000 (ABS _HEADER, through ~0xC9). Game _CODE starts
+ * at 0xCA (platforms.ts codeseg_start) — fills through what was empty
+ * space up to 0x1FF, then onward. Do not name this function start — that
+ * would place a second _start label in _CODE.
+ */
+static void pac_crt0(void) __naked {
+__asm
+        .area   _HEADER (ABS)
+        .org    0x0000
+_start::
+        jp      real_start
+
+        .org    0x0010
+        ; RST 10/18/20 (Namco sound engine)
+        .db 0x85,0x6f,0x3e,0x00,0x8c,0x67,0x7e,0xc9,0x78,0x87,0xd7,0x5f,0x23,0x56,0xeb,0xc9
+        .db 0xe1,0x87,0xd7,0x5f,0x23,0x56,0xeb,0xe9
+
+        ; IM2: OUT (0),#0x38 → CPU fetches word at 0x0038
+        .org    0x0038
+        .dw     vblank_isr
+
+vblank_isr:
+        push    af
+        push    bc
+        push    de
+        push    hl
+        push    ix
+        push    iy
+
+        ; Ack IRQ (MAME holds INT until 0x5000 bit0 is cleared)
+        xor     a
+        ld      (0x5000), a
+
+        ; Latch software sound regs → hardware WSG
+        ld      hl, #0x4e8c
+        ld      de, #0x5050
+        ld      bc, #0x0010
+        ldir
+
+        ld      a, (0x4ecc)
+        and     a
+        ld      a, (0x4ecf)
+        jr      nz, 00010$
+        ld      a, (0x4e9f)
+00010$:
+        ld      (0x5045), a
+        ld      a, (0x4edc)
+        and     a
+        ld      a, (0x4edf)
+        jr      nz, 00011$
+        ld      a, (0x4eaf)
+00011$:
+        ld      (0x504a), a
+        ld      a, (0x4eec)
+        and     a
+        ld      a, (0x4eef)
+        jr      nz, 00012$
+        ld      a, (0x4ebf)
+00012$:
+        ld      (0x504f), a
+
+        ; Frame counter — ONLY the relocatable symbol. Do NOT touch absolute
+        ; 0x4C84 (arcade ROM timer): our _DATA lives in 0x4C00+ and that
+        ; address is inside BSS (often near pac_vblank_hook / last byte).
+        ld      a, (_video_framecount)
+        inc     a
+        ld      (_video_framecount), a
+
+        call    _pac_run_vblank_hook
+
+        ld      a, #1
+        ld      (0x5000), a
+
+        pop     iy
+        pop     ix
+        pop     hl
+        pop     de
+        pop     bc
+        pop     af
+        ei
+        reti
+
+real_start:
+        ld      sp, #0x4fc0
+        ld      bc, #l__INITIALIZER
+        ld      a, b
+        or      a, c
+        jr      z, 00001$
+        ld      de, #s__INITIALIZED
+        ld      hl, #s__INITIALIZER
+        ldir
+00001$:
+        ld      hl, #0x4e8c
+        ld      de, #0x4e8d
+        ld      (hl), #0
+        ld      bc, #0x006f
+        ldir
+
+        ; BSS not cleared; keep optional VBLANK hook null until game sets it
+        xor     a
+        ld      (_pac_vblank_hook+0), a
+        ld      (_pac_vblank_hook+1), a
+
+        xor     a
+        ld      i, a
+        im      2
+        ld      a, #0x38
+        out     (0), a
+
+        jp      _main
+        .area   _CODE
+__endasm;
+}
+
+volatile byte video_framecount;
+
+/* Optional game VBLANK work (Namco sound engine, etc.). BSS → NULL. */
+void (*pac_vblank_hook)(void);
+
+void pac_run_vblank_hook(void) {
+  if (pac_vblank_hook)
+    pac_vblank_hook();
+}
+
+void pac_irq_enable(void) {
+  interrupt_enable = 1;
+  __asm__("ei");
+}
+
+word vram_addr(byte x, byte y) {
+  if (y < 2)
+    return 0x3c0 + (word)y * 32 + (29 - x);
+  if (y >= 34)
+    return (word)(y - 34) * 32 + (29 - x);
+  return 0x40 + (word)(27 - x) * 32 + (y - 2);
+}
+
+void poke_tile(byte x, byte y, byte tile, byte pal) {
+  word a;
+  if (x >= 28 || y >= 36) return;
+  a = vram_addr(x, y);
+  *((byte*)(0x4000 + a)) = tile;
+  *((byte*)(0x4400 + a)) = pal;
+}
+
+void poke_pal(byte x, byte y, byte pal) {
+  if (x >= 28 || y >= 36) return;
+  *((byte*)(0x4400 + vram_addr(x, y))) = pal;
+}
+
+byte peek_tile(byte x, byte y) {
+  if (x >= 28 || y >= 36) return T_BLANK;
+  return *((byte*)(0x4000 + vram_addr(x, y)));
+}
+
+void clrscr(byte pal) {
+  word i;
+  for (i = 0; i < 0x400; i++) {
+    ((byte*)0x4000)[i] = T_BLANK;
+    ((byte*)0x4400)[i] = pal;
+    if ((i & 63) == 0) watchdog = 0;
+  }
+}
+
+void wait_vblank(void) {
+  byte f = video_framecount;
+  while (video_framecount == f) watchdog = 0;
+}
+
+void put_digit(byte x, byte y, byte d, byte pal) {
+  if (d > 9) d = 9;
+  poke_tile(x, y, (byte)('0' + d), pal);
+}
+
+/* Arcade tile ROM: 0-9/A-Z mostly ASCII; space=0x40; extras remapped below. */
+void put_char(byte x, byte y, char ch, byte pal) {
+  byte t;
+  if (ch == ' ' || ch == '\t') t = T_BLANK;
+  else if (ch == '!') t = 0x5B;
+  else if (ch == '-') t = 0x3B;
+  else if (ch == '/') t = 0x3A;
+  else if (ch == '"') t = 0x26;
+  else if (ch >= 'a' && ch <= 'z') t = (byte)(ch - 'a' + 'A');
+  else t = (byte)ch;
+  poke_tile(x, y, t, pal);
+}
+
+void put_string(byte x, byte y, const char* s, byte pal) {
+  while (*s) {
+    put_char(x++, y, *s++, pal);
+    if (x >= 28) break;
+  }
+}
+
+/* Sprite regs: shape/color @ 0x4FF0, coords @ 0x5060 (bottom-right origin) */
+void set_sprite_ex(byte i, byte shape, byte color, byte sx, byte sy, byte flags) {
+  byte* attr = (byte*)(0x4ff0 + (i << 1));
+  byte* pos = (byte*)(0x5060 + (i << 1));
+  attr[0] = (byte)((shape << 2) | (flags & 3));
+  attr[1] = color;
+  pos[0] = (byte)(239 - sx);
+  pos[1] = (byte)(272 - sy);
+}
+
+void set_sprite(byte i, byte shape, byte color, byte sx, byte sy) {
+  set_sprite_ex(i, shape, color, sx, sy, 0);
+}
+
+void hide_sprite(byte i) {
+  set_sprite(i, 0, 0, 0, 0);
+  ((byte*)0x5060)[i * 2] = 0;
+  ((byte*)0x5060)[i * 2 + 1] = 0;
+}
+
+void hide_all_sprites(void) {
+  byte i;
+  for (i = 0; i < 8; i++) hide_sprite(i);
+}
+
+void sound_voice(byte voice, word freq, byte vol, byte wave) {
+  word wave_addr, freq_addr;
+  byte i, nibbles;
+  if (voice > 2) return;
+  if (voice == 0) { wave_addr = 0x5045; freq_addr = 0x5050; nibbles = 5; }
+  else if (voice == 1) { wave_addr = 0x504a; freq_addr = 0x5056; nibbles = 4; }
+  else { wave_addr = 0x504f; freq_addr = 0x505b; nibbles = 4; }
+  /* Voices 1/2 are 16-bit; HW treats them as 20-bit with low nibble 0.
+   * Callers always pass the voice-0 scale (≈ Hz * 11). */
+  if (voice != 0) freq >>= 4;
+  *(volatile byte*)wave_addr = wave & 7;
+  for (i = 0; i < nibbles; i++) {
+    ((volatile byte*)freq_addr)[i] = freq & 0x0f;
+    freq >>= 4;
+  }
+  ((volatile byte*)freq_addr)[nibbles] = vol & 0x0f;
+}
+
+/* Update volume only — avoids rewriting frequency mid-note (clicks / jitter). */
+void sound_vol(byte voice, byte vol) {
+  if (voice == 0) ((volatile byte*)0x5055)[0] = vol & 0x0f;
+  else if (voice == 1) ((volatile byte*)0x505a)[0] = vol & 0x0f;
+  else if (voice == 2) ((volatile byte*)0x505f)[0] = vol & 0x0f;
+}
+
+void sound_off(void) {
+  sound_voice(0, 0, 0, 0);
+  sound_voice(1, 0, 0, 0);
+  sound_voice(2, 0, 0, 0);
+}
+
+void sound_beep(word freq, byte frames) {
+  sound_enable = 1;
+  sound_voice(0, freq, 12, 1);
+  while (frames--) wait_vblank();
+  sound_voice(0, 0, 0, 0);
+}

presets/pacman/pacman_common.h

@@ -0,0 +1,109 @@
+/*
+ * Shared Pac-Man hardware helpers for 8bitworkshop demos.
+ *
+ * Link helpers only:
+ *   //#link "pacman_common.c"
+ *
+ * CRT0 (reset + IM2 VBLANK IRQ) lives in pacman_common — do not define start().
+ * Optional per-frame work: set pac_vblank_hook, then pac_irq_enable().
+ *
+ * Each demo owns its own graphics (tile/sprite/PROM data appended at the
+ * end of that .c file). Do not share one gfx object across demos.
+ *
+ * Text tile codes are ASCII: '0'-'9', 'A'-'Z', space = 0x40.
+ */
+#ifndef PACMAN_COMMON_H
+#define PACMAN_COMMON_H
+
+typedef unsigned char byte;
+typedef unsigned short word;
+typedef signed char sbyte;
+
+void main(void);
+
+/* memory-mapped I/O */
+#define interrupt_enable (*(volatile byte*)0x5000)
+#define sound_enable     (*(volatile byte*)0x5001)
+#define flip_screen      (*(volatile byte*)0x5003)
+#define watchdog         (*(volatile byte*)0x50c0)
+#define input0           (*(volatile byte*)0x5000)
+#define input1           (*(volatile byte*)0x5040)
+
+extern volatile byte video_framecount;
+
+/* Optional VBLANK callback (Namco sound engine, etc.). NULL = none. */
+extern void (*pac_vblank_hook)(void);
+void pac_run_vblank_hook(void);
+void pac_irq_enable(void);
+
+#define UP1    (!(input0 & 0x01))
+#define LEFT1  (!(input0 & 0x02))
+#define RIGHT1 (!(input0 & 0x04))
+#define DOWN1  (!(input0 & 0x08))
+/* Homebrew: Space in 8bw. On real PCB IN0 bit7 is SERVICE1 (active low). */
+#define FIRE1  (!(input0 & 0x80))
+#define COIN1  (!(input0 & 0x20))
+#define START1 (!(input1 & 0x20))
+
+/* Tile indices — font is ASCII; others are homebrew utility tiles */
+#define T_BLANK   0x40   /* empty / space */
+#define T_DOT     0x10   /* pellet */
+#define T_POWER   0x14   /* power pellet */
+#define T_WALL_TL 0x28
+#define T_WALL_TR 0x29
+#define T_WALL_H  0x2a
+#define T_WALL_V  0x2b
+#define T_WALL_BL 0x2c
+#define T_WALL_BR 0x2d
+#define T_WALL_R  0x2e
+#define T_CIRCLE  'O'    /* round letter — player marker in tile demos */
+#define T_ALIEN   0x0b   /* formation alien glyph */
+#define T_MISSILE '/'    /* thin glyph usable as a bullet */
+
+/* Homebrew sprite ROM indices for set_sprite() */
+#define S_PLAYER  0
+#define S_ALIEN   1
+#define S_BOOM1   2
+#define S_BOOM2   3
+#define S_BULLET  4
+#define S_PLAYER2 5
+/* friendly aliases used by older demos */
+#define S_PAC     S_PLAYER
+#define S_GHOST   S_ALIEN
+#define S_GHOST2  S_ALIEN
+#define S_GHOST3  S_ALIEN
+#define S_FRUIT   S_PLAYER2
+#define S_EYES    S_BOOM2
+
+/* Palette PROM entry numbers (CRAM / sprite color) */
+#define PAL_YELLOW 9
+#define PAL_CYAN   5
+#define PAL_PINK   3
+#define PAL_ORANGE 7
+#define PAL_BLUE   5 // actually cyan. no blue in this palette
+#define PAL_RED    1
+#define PAL_WHITE  15
+
+word vram_addr(byte x, byte y);
+void poke_tile(byte x, byte y, byte tile, byte pal);
+void poke_pal(byte x, byte y, byte pal);
+byte peek_tile(byte x, byte y);
+void clrscr(byte pal);
+void wait_vblank(void);
+void put_digit(byte x, byte y, byte d, byte pal);
+void put_char(byte x, byte y, char ch, byte pal);
+void put_string(byte x, byte y, const char* s, byte pal);
+void set_sprite(byte i, byte shape, byte color, byte sx, byte sy);
+/* flags: bit0 = flipY, bit1 = flipX (Pac-Man sprite attribute bits) */
+void set_sprite_ex(byte i, byte shape, byte color, byte sx, byte sy, byte flags);
+void hide_sprite(byte i);
+void hide_all_sprites(void);
+
+/* Namco WSG helpers (3 voices). freq ≈ Hz * 11 (voice-0 scale; voices 1/2
+ * are adjusted inside sound_voice). vol 0..15. wave selects wave_rom[] 0..7. */
+void sound_voice(byte voice, word freq, byte vol, byte wave);
+void sound_vol(byte voice, byte vol);
+void sound_off(void);
+void sound_beep(word freq, byte frames);
+
+#endif