47 lines
1.4 KiB
C
47 lines
1.4 KiB
C
#include "ibm.h"
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#include "io.h"
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#include "mem.h"
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#include "cpu.h"
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#include "headland.h"
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static int headland_index;
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static uint8_t headland_regs[256];
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void headland_write(uint16_t addr, uint8_t val, void *priv)
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{
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if (addr & 1)
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{
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if (headland_index == 0xc1 && !is486) val = 0;
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headland_regs[headland_index] = val;
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pclog("Headland write %02X %02X\n",headland_index,val);
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if (headland_index == 0x82)
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{
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shadowbios = val & 0x10;
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shadowbios_write = !(val & 0x10);
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if (shadowbios)
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mem_set_mem_state(0xf0000, 0x10000, MEM_READ_INTERNAL | MEM_WRITE_DISABLED);
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else
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mem_set_mem_state(0xf0000, 0x10000, MEM_READ_EXTERNAL | MEM_WRITE_INTERNAL);
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}
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}
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else
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headland_index = val;
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}
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uint8_t headland_read(uint16_t addr, void *priv)
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{
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if (addr & 1)
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{
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if ((headland_index >= 0xc0 || headland_index == 0x20) && cpu_iscyrix)
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return 0xff; /*Don't conflict with Cyrix config registers*/
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return headland_regs[headland_index];
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}
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return headland_index;
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}
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void headland_init()
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{
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io_sethandler(0x0022, 0x0002, headland_read, NULL, NULL, headland_write, NULL, NULL, NULL);
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}
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