mirror of
https://github.com/RaySollium99/picodrive.git
synced 2025-09-05 15:27:46 -04:00
sms, some cleanup
This commit is contained in:
kub
parent
1bb3f2cc8d
commit
1cdc3f8416
2 changed files with 100 additions and 45 deletions
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@ -342,6 +342,14 @@ struct PicoMisc
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unsigned int frame_count; // 1c for movies and idle det
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};
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#define PMS_MAP_AUTO 0
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#define PMS_MAP_SEGA 1
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#define PMS_MAP_CODEM 2
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#define PMS_MAP_KOREA 3
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#define PMS_MAP_MSX 4
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#define PMS_MAP_N32K 5
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#define PMS_MAP_N16K 6
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struct PicoMS
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{
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unsigned char carthw[0x10];
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137
pico/sms.c
137
pico/sms.c
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@ -8,8 +8,9 @@
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*/
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/*
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* TODO:
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* - start in a state as if BIOS ran
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* - region support
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* - start in a state as if BIOS ran (partly done for VDP registers, RAM)
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* - region support (currently only very limited PAL and Mark-III support)
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* - mappers: EEPROM, some obscure Korean (Nemesis, Janggun)
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*/
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#include "pico_int.h"
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#include "memory.h"
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@ -119,6 +120,16 @@ static void vdp_ctl_write(u8 d)
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pv->pending ^= 1;
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}
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static u8 vdp_hcounter(int cycles)
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{
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// 171 slots per scanline of 228 clocks, counted 0xf4-0x93, 0xe9-0xf3
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// this matches h counter tables in SMSVDPTest:
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// hc = (cycles+2) * 171 /228 -1 + 0xf4;
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int hc = (((cycles+2) * ((171<<8)/228))>>8)-1 + 0xf4; // Q8 to avoid dividing
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if (hc > 0x193) hc += 0xe9-0x93-1;
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return hc;
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}
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static unsigned char z80_sms_in(unsigned short a)
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{
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unsigned char d = 0xff;
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@ -227,14 +238,8 @@ static void z80_sms_out(unsigned short a, unsigned char d)
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Pico.ms.io_gg[a] = d;
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} else {
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// pad. latch hcounter if one of the TH lines is switched to 1
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if ((Pico.ms.io_ctl ^ d) & d & 0xa0) {
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unsigned c = 228-z80_cyclesLeft;
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// 171 slots per scanline of 228 clocks, counted 0xf4-0x93,0xe9-0xf3
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// this matches h counter tables in SMSVDPTest
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c = (((c+2) * ((171<<8)/228))>>8)-1 + 0xf4; // Q8 to avoid dividing
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if (c > 0x193) c += 0xe9-0x93-1;
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Pico.ms.vdp_hlatch = (u8)c;
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}
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if ((Pico.ms.io_ctl ^ d) & d & 0xa0)
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Pico.ms.vdp_hlatch = vdp_hcounter(228 - z80_cyclesLeft);
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Pico.ms.io_ctl = d;
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}
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break;
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@ -273,9 +278,10 @@ static void write_sram(unsigned short a, unsigned char d)
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// 16KB bank mapping for Sega mapper
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static void write_bank_sega(unsigned short a, unsigned char d)
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{
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if (Pico.ms.mapper != 1 && (Pico.ms.mapper || d == 0)) return;
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// avoid mapper detection for RAM fill with 0
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if (Pico.ms.mapper != PMS_MAP_SEGA && (Pico.ms.mapper || d == 0)) return;
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elprintf(EL_Z80BNK, "bank 16k %04x %02x @ %04x", a, d, z80_pc());
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Pico.ms.mapper = 1;
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Pico.ms.mapper = PMS_MAP_SEGA;
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Pico.ms.carthw[a & 0x0f] = d;
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switch (a & 0x0f)
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@ -307,12 +313,26 @@ static void write_bank_sega(unsigned short a, unsigned char d)
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}
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}
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// 8KB ROM mapping for MSX mapper
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// 16KB bank mapping for Codemasters mapper, TODO: SRAM support
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static void write_bank_codem(unsigned short a, unsigned char d)
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{
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// don't detect @0x0 to avoid confusing with MSX
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if (Pico.ms.mapper != PMS_MAP_CODEM && (Pico.ms.mapper || (a|d) == 0)) return;
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elprintf(EL_Z80BNK, "bank 16k %04x %02x @ %04x", a, d, z80_pc());
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Pico.ms.mapper = PMS_MAP_CODEM;
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Pico.ms.carthw[a>>14] = d;
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d &= bank_mask;
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z80_map_set(z80_read_map, a, a+0x3fff, Pico.rom + (d << 14), 0);
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}
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// 8KB bank mapping for MSX mapper
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static void write_bank_msx(unsigned short a, unsigned char d)
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{
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if (Pico.ms.mapper != 2 && (Pico.ms.mapper || (a|d) == 0)) return;
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// don't detect @0x0 to avoid confusing with Codemasters
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if (Pico.ms.mapper != PMS_MAP_MSX && (Pico.ms.mapper || (a|d) == 0)) return;
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elprintf(EL_Z80BNK, "bank 8k %04x %02x @ %04x", a, d, z80_pc());
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Pico.ms.mapper = 2; // TODO define (more) mapper types
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Pico.ms.mapper = PMS_MAP_MSX;
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Pico.ms.carthw[a] = d;
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a = (a^2)*0x2000 + 0x4000;
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@ -320,44 +340,62 @@ static void write_bank_msx(unsigned short a, unsigned char d)
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z80_map_set(z80_read_map, a, a+0x1fff, Pico.rom + (d << 13), 0);
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}
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static void write_bank_32k(unsigned short a, unsigned char d)
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// 32KB bank mapping for Korean n-in-1 packs
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static void write_bank_n32k(unsigned short a, unsigned char d)
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{
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if (Pico.ms.mapper != 3 && (Pico.ms.mapper || z80_pc() < 0xc000)) return;
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// code must be in RAM since all visible ROM space is swapped
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if (Pico.ms.mapper != PMS_MAP_N32K && (Pico.ms.mapper || z80_pc() < 0xc000)) return;
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elprintf(EL_Z80BNK, "bank 32k %04x %02x @ %04x", a, d, z80_pc());
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Pico.ms.mapper = 3; // TODO define (more) mapper types
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Pico.ms.mapper = PMS_MAP_N32K;
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Pico.ms.carthw[0xf] = d;
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d &= bank_mask >> 1;
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z80_map_set(z80_read_map, 0, 0x7fff, Pico.rom + (d << 15), 0);
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z80_map_set(z80_read_map, 0, 0x7fff, Pico.rom + (d << 15), 0);
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}
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// TODO mapping is currently auto-selecting, but that's not very reliable.
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// 16KB bank mapping for Korean n-in-1 packs
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static void write_bank_n16k(unsigned short a, unsigned char d)
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{
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// code must be in RAM since all visible ROM space is swapped
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if (Pico.ms.mapper != PMS_MAP_N16K && (Pico.ms.mapper || z80_pc() < 0xc000)) return;
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elprintf(EL_Z80BNK, "bank 16k %04x %02x @ %04x", a, d, z80_pc());
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Pico.ms.mapper = PMS_MAP_N16K;
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Pico.ms.carthw[a>>14] = d;
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d &= bank_mask;
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a = a & 0xc000;
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// the top bank shifts with the bottom bank.
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if (a == 0x8000) d += Pico.ms.carthw[0] & 0x30;
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z80_map_set(z80_read_map, a, a+0x3fff, Pico.rom + (d << 14), 0);
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}
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// TODO mapping is currently auto-selecting, but that's not totally reliable.
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// Before adding more mappers this should be revised.
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static void xwrite(unsigned int a, unsigned char d)
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{
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elprintf(EL_IO, "z80 write [%04x] %02x", a, d);
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if (a >= 0xc000)
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PicoMem.zram[a & 0x1fff] = d;
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// korean 32k. 1 selectable 32KB bank at the bottom
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// NB the sequence of mappers is crucial for the auto detection
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// Korean n-in-1. 1 selectable 32KB bank at the bottom
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if (a == 0xffff)
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write_bank_32k(a, d);
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// Sega. Maps 4 bank 16KB each
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write_bank_n32k(a, d);
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// Sega. Maps 3 banks 16KB each, SRAM
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if (a >= 0xfff8)
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write_bank_sega(a, d);
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// Codemasters. Similar to Sega, but different addresses
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// NB mapping on 0x0000 collides with MSX mapper, but AFAICT CM isn't using it
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// if (a == 0x0000)
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// write_bank_sega(0xfffd, d);
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if (a == 0x4000)
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write_bank_sega(0xfffe, d);
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if (a == 0x8000)
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write_bank_sega(0xffff, d);
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// Korean. 1 selectable 16KB bank at the top
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if (a == 0xa000)
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write_bank_sega(0xffff, d);
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// MSX. 4 selectable 8KB banks at the top
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if (a <= 0x0003)
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write_bank_msx(a, d);
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// Codemasters. Similar to Sega, but different addresses
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if (a < 0xc000 && (a & 0x3fff) == 0)
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write_bank_codem(a, d);
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// Korean. 1 selectable 16KB bank at the top
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if (a == 0xa000)
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write_bank_codem(0x8000, d);
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// Korean n-in-1. 2 selectable 16KB banks, top bank has offset from bottom one
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if (a == 0x3ffe || a == 0x7fff || a == 0xbfff)
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write_bank_n16k(a, d);
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}
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void PicoResetMS(void)
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@ -401,8 +439,8 @@ void PicoResetMS(void)
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Pico.video.reg[9] = 0x00;
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Pico.video.reg[10] = 0xff;
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// BIOS, clean zram
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memset(PicoMem.zram, 0, sizeof(PicoMem.zram));
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// BIOS, clear zram (fake unitialized on japanese NTSC devices)
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memset(PicoMem.zram, PicoIn.regionOverride&1 ? 0xf0:0, sizeof(PicoMem.zram));
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}
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void PicoPowerMS(void)
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@ -424,6 +462,7 @@ void PicoPowerMS(void)
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tmp = 1 << s;
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bank_mask = (tmp - 1) >> 14;
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PicoMem.ioports[0] = 0xc3; // hack to jump @0 at end of RAM to wrap around
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Pico.ms.mapper = 0;
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PicoReset();
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}
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@ -447,15 +486,19 @@ void PicoMemSetupMS(void)
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Cz80_Set_OUTPort(&CZ80, z80_sms_out);
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#endif
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// memory mapper setup
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// memory mapper setup, linear mapping of 1st 48KB
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u8 mapper = Pico.ms.mapper;
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if (Pico.ms.mapper == 2) {
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xwrite(0x0000, 0);
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xwrite(0x0001, 0);
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xwrite(0x0002, 0);
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xwrite(0x0003, 0);
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} else if (Pico.ms.mapper == 3) {
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if (Pico.ms.mapper == PMS_MAP_MSX) {
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xwrite(0x0000, 4);
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xwrite(0x0001, 5);
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xwrite(0x0002, 2);
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xwrite(0x0003, 3);
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} else if (Pico.ms.mapper == PMS_MAP_N32K) {
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xwrite(0xffff, 0);
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} else if (Pico.ms.mapper == PMS_MAP_CODEM) {
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xwrite(0x0000, 0);
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xwrite(0x4000, 1);
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xwrite(0x8000, 2);
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} else {
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xwrite(0xfffc, 0);
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xwrite(0xfffd, 0);
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@ -468,13 +511,17 @@ void PicoMemSetupMS(void)
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void PicoStateLoadedMS(void)
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{
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u8 mapper = Pico.ms.mapper;
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if (Pico.ms.mapper == 2) {
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if (Pico.ms.mapper == PMS_MAP_MSX) {
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xwrite(0x0000, Pico.ms.carthw[0]);
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xwrite(0x0001, Pico.ms.carthw[1]);
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xwrite(0x0002, Pico.ms.carthw[2]);
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xwrite(0x0003, Pico.ms.carthw[3]);
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} else if (Pico.ms.mapper == 3) {
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} else if (Pico.ms.mapper == PMS_MAP_N32K) {
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xwrite(0xffff, Pico.ms.carthw[0x0f]);
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} else if (Pico.ms.mapper == PMS_MAP_CODEM) {
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xwrite(0x0000, Pico.ms.carthw[0]);
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xwrite(0x4000, Pico.ms.carthw[1]);
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xwrite(0x8000, Pico.ms.carthw[2]);
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} else {
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xwrite(0xfffc, Pico.ms.carthw[0x0c]);
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xwrite(0xfffd, Pico.ms.carthw[0x0d]);
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