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#include <stdio.h>
#include <stdlib.h>
#ifdef ATARIST
#include <osbind.h>
#endif
static char *rcsid = "$Id: cpu_asm.c,v 1.2 1998/02/21 15:02:46 david Exp $";
#define FALSE 0
#define TRUE 1
#include "atari.h"
#include "cpu_asm.h"
#include "pia.h"
#include "gtia.h"
#include "sio.h"
#include "pokey.h"
#include "antic.h"
long CEKEJ;
extern UBYTE IRQ;
extern int wsync_halt;
extern UWORD break_addr;
/*
==========================================================
Emulated Registers and Flags are kept local to this module
==========================================================
*/
#define GetByte(addr) ((attrib[addr] == HARDWARE) ? Atari800_GetByte(addr) : memory[addr])
#define PutByte(addr,byte) if (attrib[addr] == RAM) memory[addr] = byte; else if (attrib[addr] == HARDWARE) if (Atari800_PutByte(addr,byte)) break;
#define RAM 0
#define ROM 1
#define HARDWARE 2
int count[256];
extern void tisk(void);
UBYTE memory[65536];
UBYTE attrib[65536];
/*
===============================================================
Z flag: This actually contains the result of an operation which
would modify the Z flag. The value is tested for
equality by the BEQ and BNE instruction.
===============================================================
*/
UBYTE BCDtoDEC[256];
UBYTE DECtoBCD[256];
void CPU_Reset(void)
{
int i;
for (i = 0; i < 256; i++) {
BCDtoDEC[i] = ((i >> 4) & 0xf) * 10 + (i & 0xf);
DECtoBCD[i] = (((i % 100) / 10) << 4) | (i % 10);
#ifdef PROFILE
count[i] = 0;
#endif
}
IRQ = 0x00;
regP = 0x20; /* The unused bit is always 1 */
regS = 0xff;
regPC = (GetByte(0xfffd) << 8) | GetByte(0xfffc);
}
/* it was there only for debug purposes.....
#define PHP data = (N & 0x80); \
data |= V ? 0x40 : 0; \
data |= (regP & 0x3c); \
data |= (Z == 0) ? 0x02 : 0; \
data |= C; \
memory[0x0100 + S--] = data;
void NMI (void)
{
UBYTE S = regS;
UBYTE data;
memory[0x0100 + S--] = regPC >> 8;
memory[0x0100 + S--] = regPC & 0xff;
memory[0x100 + S--] = regP;
SetI;
regPC = (memory[0xfffb] << 8) | memory[0xfffa];
regS = S;
}
*/
void SetRAM(int addr1, int addr2)
{
int i;
for (i = addr1; i <= addr2; i++) {
attrib[i] = RAM;
}
}
void SetROM(int addr1, int addr2)
{
int i;
for (i = addr1; i <= addr2; i++) {
attrib[i] = ROM;
}
}
void SetHARDWARE(int addr1, int addr2)
{
int i;
for (i = addr1; i <= addr2; i++) {
attrib[i] = HARDWARE;
}
}
UBYTE GETBYTE(UWORD addr)
{
UBYTE byte;
/*
============================================================
GTIA, POKEY, PIA and ANTIC do not fully decode their address
------------------------------------------------------------
PIA (At least) is fully decoded when emulating the XL/XE
============================================================
*/
switch (addr & 0xff00) {
case 0xd000: /* GTIA */
byte = GTIA_GetByte(addr - 0xd000);
break;
case 0xd200: /* POKEY */
byte = POKEY_GetByte(addr - 0xd200);
break;
case 0xd300: /* PIA */
byte = PIA_GetByte(addr - 0xd300);
break;
case 0xd400: /* ANTIC */
byte = ANTIC_GetByte(addr - 0xd400);
break;
case 0xc000: /* GTIA - 5200 */
byte = GTIA_GetByte(addr - 0xc000);
break;
case 0xe800: /* POKEY - 5200 */
byte = POKEY_GetByte(addr - 0xe800);
break;
case 0xeb00: /* POKEY - 5200 */
byte = POKEY_GetByte(addr - 0xeb00);
break;
default:
break;
}
return byte;
}
int PUTBYTE(UWORD addr, UBYTE byte)
{
int abort = TRUE; /*FALSE; */
/*
============================================================
GTIA, POKEY, PIA and ANTIC do not fully decode their address
------------------------------------------------------------
PIA (At least) is fully decoded when emulating the XL/XE
============================================================
*/
switch (addr & 0xff00) {
case 0xd000: /* GTIA */
abort = GTIA_PutByte(addr - 0xd000, byte);
break;
case 0xd200: /* POKEY */
abort = POKEY_PutByte(addr - 0xd200, byte);
break;
case 0xd300: /* PIA */
abort = PIA_PutByte(addr - 0xd300, byte);
break;
case 0xd400: /* ANTIC */
abort = ANTIC_PutByte(addr - 0xd400, byte);
if (wsync_halt)
abort = TRUE;
break;
case 0xd500: /* Super Cartridges */
abort = SuperCart_PutByte(addr, byte);
break;
case 0xc000: /* GTIA - 5200 */
abort = GTIA_PutByte(addr - 0xc000, byte);
break;
case 0xeb00: /* POKEY - 5200 */
abort = POKEY_PutByte(addr - 0xeb00, byte);
break;
default:
break;
}
return abort;
}
void CPU_GetStatus(void)
{
CPUGET();
}
void GenerateIRQ(void)
{
IRQ = 1;
GO(0); /* does not execute any instruction */
}
void tisk(void)
{
void *adresa = (long *) 0x400000;
printf("OLD %d %d %d %d %d %d\n", *(UBYTE *) (adresa - 1), *(UBYTE *) (adresa - 2),
*(UBYTE *) (adresa - 3), *(UBYTE *) (adresa - 4), *(UBYTE *) (adresa - 5), *(UWORD *) (adresa - 8));
printf("NEW %d %d %d %d %d %d\n", regP, regS, regA, regX, regY, regPC);
}
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