119 lines
3.9 KiB
C
119 lines
3.9 KiB
C
#include "ibm.h"
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#include "acc2168.h"
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#include "cpu.h"
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#include "io.h"
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#include "mem.h"
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#include "x86.h"
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static struct
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{
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int reg_idx;
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uint8_t regs[256];
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uint8_t port_62;
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} acc2168;
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static void acc2168_shadow_recalc()
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{
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if (acc2168.regs[0x02] & 8)
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{
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switch (acc2168.regs[0x02] & 0x30)
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{
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case 0x00:
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mem_set_mem_state(0xf0000, 0x10000, MEM_READ_EXTERNAL | MEM_WRITE_INTERNAL);
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break;
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case 0x10:
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mem_set_mem_state(0xf0000, 0x10000, MEM_READ_INTERNAL | MEM_WRITE_INTERNAL);
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break;
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case 0x20:
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mem_set_mem_state(0xf0000, 0x10000, MEM_READ_EXTERNAL | MEM_WRITE_EXTERNAL);
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break;
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case 0x30:
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mem_set_mem_state(0xf0000, 0x10000, MEM_READ_INTERNAL | MEM_WRITE_EXTERNAL);
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break;
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}
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}
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else
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mem_set_mem_state(0xf0000, 0x10000, MEM_READ_EXTERNAL | MEM_WRITE_EXTERNAL);
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if (acc2168.regs[0x02] & 4)
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{
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switch (acc2168.regs[0x02] & 0x30)
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{
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case 0x00:
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mem_set_mem_state(0xe0000, 0x10000, MEM_READ_EXTERNAL | MEM_WRITE_INTERNAL);
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break;
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case 0x10:
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mem_set_mem_state(0xe0000, 0x10000, MEM_READ_INTERNAL | MEM_WRITE_INTERNAL);
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break;
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case 0x20:
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mem_set_mem_state(0xe0000, 0x10000, MEM_READ_EXTERNAL | MEM_WRITE_EXTERNAL);
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break;
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case 0x30:
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mem_set_mem_state(0xe0000, 0x10000, MEM_READ_INTERNAL | MEM_WRITE_EXTERNAL);
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break;
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}
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}
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else
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mem_set_mem_state(0xe0000, 0x10000, MEM_READ_EXTERNAL | MEM_WRITE_EXTERNAL);
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}
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static void acc2168_write(uint16_t addr, uint8_t val, void *p)
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{
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// pclog("acc2168_write: addr=%04x val=%02x\n", addr, val);
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if (!(addr & 1))
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acc2168.reg_idx = val;
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else
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{
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acc2168.regs[acc2168.reg_idx] = val;
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// pclog("acc2168_write: idx=%02x val=%02x %04x:%04x\n", acc2168.reg_idx, val, CS,cpu_state.pc);
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switch (acc2168.reg_idx)
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{
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case 0x02:
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acc2168_shadow_recalc();
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break;
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}
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}
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}
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static uint8_t acc2168_read(uint16_t addr, void *p)
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{
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if (!(addr & 1))
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return acc2168.reg_idx;
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// pclog("acc2168_read: idx=%02x val=%02x\n", acc2168.reg_idx, acc2168.regs[acc2168.reg_idx]);
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return acc2168.regs[acc2168.reg_idx];
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}
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static uint8_t port78_read(uint16_t addr, void *p)
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{
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return 0;
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}
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static uint8_t port92_read(uint16_t addr, void *p)
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{
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return acc2168.port_62 | 0xfc;
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}
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static void port92_write(uint16_t addr, uint8_t val, void *p)
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{
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if ((mem_a20_alt ^ val) & 2)
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{
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mem_a20_alt = val & 2;
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mem_a20_recalc();
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}
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if ((~acc2168.port_62 & val) & 1)
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{
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softresetx86();
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cpu_set_edx();
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}
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acc2168.port_62 = val | 0xfC;
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}
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void acc2168_init()
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{
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memset(&acc2168, 0, sizeof(acc2168));
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io_sethandler(0x00f2, 0x0002, acc2168_read, NULL, NULL, acc2168_write, NULL, NULL, NULL);
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io_sethandler(0x0078, 0x0001, port78_read, NULL, NULL, NULL, NULL, NULL, NULL);
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io_sethandler(0x0092, 0x0001, port92_read, NULL, NULL, port92_write, NULL, NULL, NULL);
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}
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