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Added Elonex PC-425X emulation.

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This commit is contained in:
SarahW 2018-02-12 20:06:00 +00:00
commit 4cc15d9b7e
18 changed files with 160 additions and 13 deletions
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76
src/sl82c460.c Normal file
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#include "ibm.h"
#include "io.h"
#include "mem.h"
#include "sl82c460.h"
static struct
{
int reg_idx;
uint8_t regs[256];
} sl82c460;
static void sl82c460_shadow_set(uint32_t base, uint32_t size, int state)
{
switch (state)
{
case 0:
mem_set_mem_state(base, size, MEM_READ_EXTERNAL | MEM_WRITE_EXTERNAL);
break;
case 1:
mem_set_mem_state(base, size, MEM_READ_EXTERNAL | MEM_WRITE_INTERNAL);
break;
case 2:
mem_set_mem_state(base, size, MEM_READ_INTERNAL | MEM_WRITE_EXTERNAL);
break;
case 3:
mem_set_mem_state(base, size, MEM_READ_INTERNAL | MEM_WRITE_INTERNAL);
break;
}
}
static void sl82c460_shadow_recalc()
{
sl82c460_shadow_set(0xc0000, 0x4000, sl82c460.regs[0x18] & 3);
sl82c460_shadow_set(0xc4000, 0x4000, (sl82c460.regs[0x18] >> 2) & 3);
sl82c460_shadow_set(0xc8000, 0x4000, (sl82c460.regs[0x18] >> 4) & 3);
sl82c460_shadow_set(0xcc000, 0x4000, (sl82c460.regs[0x18] >> 6) & 3);
sl82c460_shadow_set(0xd0000, 0x4000, sl82c460.regs[0x19] & 3);
sl82c460_shadow_set(0xd4000, 0x4000, (sl82c460.regs[0x19] >> 2) & 3);
sl82c460_shadow_set(0xd8000, 0x4000, (sl82c460.regs[0x19] >> 4) & 3);
sl82c460_shadow_set(0xdc000, 0x4000, (sl82c460.regs[0x19] >> 6) & 3);
sl82c460_shadow_set(0xe0000, 0x10000, (sl82c460.regs[0x1b] >> 4) & 3);
sl82c460_shadow_set(0xf0000, 0x10000, (sl82c460.regs[0x1b] >> 2) & 3);
}
static void sl82c460_write(uint16_t addr, uint8_t val, void *p)
{
if (!(addr & 1))
sl82c460.reg_idx = val;
else
{
// pclog("SL82C460 write %02x %02x\n", sl82c460.reg_idx, val);
sl82c460.regs[sl82c460.reg_idx] = val;
switch (sl82c460.reg_idx)
{
case 0x18: case 0x19: case 0x1b:
sl82c460_shadow_recalc();
break;
}
}
}
static uint8_t sl82c460_read(uint16_t addr, void *p)
{
if (!(addr & 1))
return sl82c460.reg_idx;
return sl82c460.regs[sl82c460.reg_idx];
}
void sl82c460_init()
{
memset(&sl82c460, 0, sizeof(sl82c460));
io_sethandler(0x00a8, 0x0002, sl82c460_read, NULL, NULL, sl82c460_write, NULL, NULL, NULL);
}