+/*
+ * SMS emulation
+ * (C) notaz, 2009-2010
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
+/*
+ * TODO:
+ * - start in a state as if BIOS ran
+ * - remaining status flags (OVR/COL)
+ * - RAM support in mapper
+ * - region support
+ * - SN76496 DAC-like usage
+ * - H counter
+ */
#include "pico_int.h"
+#include "memory.h"
+#include "sound/sn76496.h"
-static unsigned char z80_sms_in(unsigned short p)
+static unsigned char vdp_data_read(void)
{
- elprintf(EL_ANOMALY, "Z80 port %04x read", p);
- return 0xff;
+ struct PicoVideo *pv = &Pico.video;
+ unsigned char d;
+
+ d = Pico.vramb[pv->addr];
+ pv->addr = (pv->addr + 1) & 0x3fff;
+ pv->pending = 0;
+ return d;
+}
+
+static unsigned char vdp_ctl_read(void)
+{
+ unsigned char d = Pico.video.pending_ints << 7;
+ Pico.video.pending = 0;
+ Pico.video.pending_ints = 0;
+
+ elprintf(EL_SR, "VDP sr: %02x", d);
+ return d;
+}
+
+static void vdp_data_write(unsigned char d)
+{
+ struct PicoVideo *pv = &Pico.video;
+
+ if (pv->type == 3) {
+ Pico.cram[pv->addr & 0x1f] = d;
+ Pico.m.dirtyPal = 1;
+ } else {
+ Pico.vramb[pv->addr] = d;
+ }
+ pv->addr = (pv->addr + 1) & 0x3fff;
+
+ pv->pending = 0;
+}
+
+static void vdp_ctl_write(unsigned char d)
+{
+ struct PicoVideo *pv = &Pico.video;
+
+ if (pv->pending) {
+ if ((d >> 6) == 2) {
+ pv->reg[d & 0x0f] = pv->addr;
+ elprintf(EL_IO, " VDP r%02x=%02x", d & 0x0f, pv->addr & 0xff);
+ }
+ pv->type = d >> 6;
+ pv->addr &= 0x00ff;
+ pv->addr |= (d & 0x3f) << 8;
+ } else {
+ pv->addr &= 0x3f00;
+ pv->addr |= d;
+ }
+ pv->pending ^= 1;
+}
+
+static unsigned char z80_sms_in(unsigned short a)
+{
+ unsigned char d = 0;
+
+ elprintf(EL_IO, "z80 port %04x read", a);
+ a &= 0xc1;
+ switch (a)
+ {
+ case 0x00:
+ case 0x01:
+ d = 0xff;
+ break;
+
+ case 0x40: /* V counter */
+ d = Pico.video.v_counter;
+ elprintf(EL_HVCNT, "V counter read: %02x", d);
+ break;
+
+ case 0x41: /* H counter */
+ d = Pico.m.rotate++;
+ elprintf(EL_HVCNT, "H counter read: %02x", d);
+ break;
+
+ case 0x80:
+ d = vdp_data_read();
+ break;
+
+ case 0x81:
+ d = vdp_ctl_read();
+ break;
+
+ case 0xc0: /* I/O port A and B */
+ d = ~((PicoPad[0] & 0x3f) | (PicoPad[1] << 6));
+ break;
+
+ case 0xc1: /* I/O port B and miscellaneous */
+ d = (Pico.ms.io_ctl & 0x80) | ((Pico.ms.io_ctl << 1) & 0x40) | 0x30;
+ d |= ~(PicoPad[1] >> 2) & 0x0f;
+ break;
+ }
+
+ elprintf(EL_IO, "ret = %02x", d);
+ return d;
+}
+
+static void z80_sms_out(unsigned short a, unsigned char d)
+{
+ elprintf(EL_IO, "z80 port %04x write %02x", a, d);
+ a &= 0xc1;
+ switch (a)
+ {
+ case 0x01:
+ Pico.ms.io_ctl = d;
+ break;
+
+ case 0x40:
+ case 0x41:
+ if (PicoOpt & POPT_EN_PSG)
+ SN76496Write(d);
+ break;
+
+ case 0x80:
+ vdp_data_write(d);
+ break;
+
+ case 0x81:
+ vdp_ctl_write(d);
+ break;
+ }
}
-static void z80_sms_out(unsigned short p, unsigned char d)
+static int bank_mask;
+
+static void write_bank(unsigned short a, unsigned char d)
{
- elprintf(EL_ANOMALY, "Z80 port %04x write %02x", p, d);
+ elprintf(EL_Z80BNK, "bank %04x %02x @ %04x", a, d, z80_pc());
+ switch (a & 0x0f)
+ {
+ case 0x0c:
+ elprintf(EL_STATUS|EL_ANOMALY, "%02x written to control reg!", d);
+ break;
+ case 0x0d:
+ if (d != 0)
+ elprintf(EL_STATUS|EL_ANOMALY, "bank0 changed to %d!", d);
+ break;
+ case 0x0e:
+ d &= bank_mask;
+ z80_map_set(z80_read_map, 0x4000, 0x7fff, Pico.rom + (d << 14), 0);
+#ifdef _USE_CZ80
+ Cz80_Set_Fetch(&CZ80, 0x4000, 0x7fff, (FPTR)Pico.rom + (d << 14));
+#endif
+ break;
+ case 0x0f:
+ d &= bank_mask;
+ z80_map_set(z80_read_map, 0x8000, 0xbfff, Pico.rom + (d << 14), 0);
+#ifdef _USE_CZ80
+ Cz80_Set_Fetch(&CZ80, 0x8000, 0xbfff, (FPTR)Pico.rom + (d << 14));
+#endif
+ break;
+ }
+ Pico.ms.carthw[a & 0x0f] = d;
}
-static unsigned char MEMH_FUNC xread(unsigned short a)
+static void xwrite(unsigned int a, unsigned char d)
{
- elprintf(EL_ANOMALY, "Z80 read [%04x]", a);
- return 0;
+ elprintf(EL_IO, "z80 write [%04x] %02x", a, d);
+ if (a >= 0xc000)
+ Pico.zram[a & 0x1fff] = d;
+ if (a >= 0xfff8)
+ write_bank(a, d);
}
-static void MEMH_FUNC xwrite(unsigned int a, unsigned char data)
+void PicoResetMS(void)
{
- elprintf(EL_ANOMALY, "Z80 write [%04x] %02x", a, data);
+ z80_reset();
+ PsndReset(); // pal must be known here
}
void PicoPowerMS(void)
{
+ int s, tmp;
+
+ memset(&Pico.ram,0,(unsigned char *)&Pico.rom - Pico.ram);
+ memset(&Pico.video,0,sizeof(Pico.video));
+ memset(&Pico.m,0,sizeof(Pico.m));
+ Pico.m.pal = 0;
+
+ // calculate a mask for bank writes.
+ // ROM loader has aligned the size for us, so this is safe.
+ s = 0; tmp = Pico.romsize;
+ while ((tmp >>= 1) != 0)
+ s++;
+ if (Pico.romsize > (1 << s))
+ s++;
+ tmp = 1 << s;
+ bank_mask = (tmp - 1) >> 14;
+
+ Pico.ms.carthw[0x0e] = 1;
+ Pico.ms.carthw[0x0f] = 2;
+
+ PicoReset();
}
void PicoMemSetupMS(void)
{
z80_map_set(z80_read_map, 0x0000, 0xbfff, Pico.rom, 0);
z80_map_set(z80_read_map, 0xc000, 0xdfff, Pico.zram, 0);
- z80_map_set(z80_read_map, 0xe000, 0xffff, xread, 1);
+ z80_map_set(z80_read_map, 0xe000, 0xffff, Pico.zram, 0);
- z80_map_set(z80_write_map, 0x0000, 0xbfff, Pico.rom, 0);
+ z80_map_set(z80_write_map, 0x0000, 0xbfff, xwrite, 1);
z80_map_set(z80_write_map, 0xc000, 0xdfff, Pico.zram, 0);
z80_map_set(z80_write_map, 0xe000, 0xffff, xwrite, 1);
drZ80.z80_out = z80_sms_out;
#endif
#ifdef _USE_CZ80
- Cz80_Set_Fetch(&CZ80, 0x0000, 0xbfff, (UINT32)Pico.rom);
- Cz80_Set_Fetch(&CZ80, 0xc000, 0xdfff, (UINT32)Pico.zram);
+ Cz80_Set_Fetch(&CZ80, 0x0000, 0xbfff, (FPTR)Pico.rom);
+ Cz80_Set_Fetch(&CZ80, 0xc000, 0xdfff, (FPTR)Pico.zram);
+ Cz80_Set_Fetch(&CZ80, 0xe000, 0xffff, (FPTR)Pico.zram);
Cz80_Set_INPort(&CZ80, z80_sms_in);
Cz80_Set_OUTPort(&CZ80, z80_sms_out);
#endif
}
+void PicoStateLoadedMS(void)
+{
+ write_bank(0xfffe, Pico.ms.carthw[0x0e]);
+ write_bank(0xffff, Pico.ms.carthw[0x0f]);
+}
+
void PicoFrameMS(void)
{
- z80_run(OSC_NTSC / 13 / 60);
+ struct PicoVideo *pv = &Pico.video;
+ int is_pal = Pico.m.pal;
+ int lines = is_pal ? 313 : 262;
+ int cycles_line = is_pal ? 58020 : 58293; /* (226.6 : 227.7) * 256 */
+ int cycles_done = 0, cycles_aim = 0;
+ int skip = PicoSkipFrame;
+ int lines_vis = 192;
+ int hint; // Hint counter
+ int nmi;
+ int y;
+
+ PsndStartFrame();
+
+ nmi = (PicoPad[0] >> 7) & 1;
+ if (!Pico.ms.nmi_state && nmi)
+ z80_nmi();
+ Pico.ms.nmi_state = nmi;
+
+ PicoFrameStartMode4();
+ hint = pv->reg[0x0a];
+
+ for (y = 0; y < lines; y++)
+ {
+ pv->v_counter = Pico.m.scanline = y;
+ if (y > 218)
+ pv->v_counter = y - 6;
+
+ if (y < lines_vis && !skip)
+ PicoLineMode4(y);
+
+ if (y <= lines_vis)
+ {
+ if (--hint < 0)
+ {
+ hint = pv->reg[0x0a];
+ pv->pending_ints |= 2;
+ if (pv->reg[0] & 0x10) {
+ elprintf(EL_INTS, "hint");
+ z80_int();
+ }
+ }
+ }
+ else if (y == lines_vis + 1) {
+ pv->pending_ints |= 1;
+ if (pv->reg[1] & 0x20) {
+ elprintf(EL_INTS, "vint");
+ z80_int();
+ }
+ }
+
+ cycles_aim += cycles_line;
+ cycles_done += z80_run((cycles_aim - cycles_done) >> 8) << 8;
+ }
+
+ if (PsndOut)
+ PsndGetSamplesMS();
+}
+
+void PicoFrameDrawOnlyMS(void)
+{
+ int lines_vis = 192;
+ int y;
+
+ PicoFrameStartMode4();
+
+ for (y = 0; y < lines_vis; y++)
+ PicoLineMode4(y);
}
notaz.gp2x.de / picodrive.git / blobdiff