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Initial commit of zxbox - a ZX Spectrum emulator ported by Anton Romanov. It theoretically runs on all targets, but I have not included it in the Archos builds because it is just too slow to be usable.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@10950 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Dave Chapman 2006-09-15 11:11:16 +00:00
parent 1350d57751
commit 05a7f14f8d
88 changed files with 19624 additions and 0 deletions
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176
apps/plugins/zxbox/z80_step.c Normal file
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/*
* Copyright (C) 1996-1998 Szeredi Miklos
* Email: mszeredi@inf.bme.hu
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version. See the file COPYING.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include "z80_def.h"
byte z80c_incf_tbl[256];
byte z80c_decf_tbl[256];
byte z80c_addf_tbl[256];
byte z80c_subf_tbl[256];
byte z80c_orf_tbl[256];
void PRNM(pushpc)(void)
{
#ifdef PROCP
Z80 *z80p;
z80p = &PRNM(proc);
#endif
SP--;
PUTMEM(SP, SPP, PCH);
SP--;
PUTMEM(SP, SPP, PCL);
}
static int parity(int b)
{
int i;
int par;
par = 0;
for(i = 8; i; i--) par ^= (b & 1), b >>= 1;
return par;
}
void PRNM(local_init)(void)
{
int i;
#ifdef PROCP
Z80 *z80p;
z80p = &PRNM(proc);
#endif
for(i = 0; i < 0x100; i++) {
z80c_incf_tbl[i] = z80c_decf_tbl[i] = z80c_orf_tbl[i] = 0;
z80c_orf_tbl[i] |= i & (SF | B3F | B5F);
z80c_incf_tbl[i] |= i & (SF | B3F | B5F);
z80c_decf_tbl[i] |= i & (SF | B3F | B5F);
if(!parity(i)) z80c_orf_tbl[i] |= PVF;
}
z80c_incf_tbl[0] |= ZF;
z80c_decf_tbl[0] |= ZF;
z80c_orf_tbl[0] |= ZF;
z80c_incf_tbl[0x80] |= PVF;
z80c_decf_tbl[0x7F] |= PVF;
for(i = 0; i < 0x100; i++) {
int cr, c1, c2;
int hr, h1, h2;
int b5r;
cr = i & 0x80;
c1 = i & 0x40;
b5r = i & 0x20;
c2 = i & 0x10;
hr = i & 0x08;
h1 = i & 0x04;
h2 = i & 0x01;
z80c_addf_tbl[i] = 0;
z80c_subf_tbl[i] = 0;
if(cr) {
z80c_addf_tbl[i] |= SF;
z80c_subf_tbl[i] |= SF;
}
if(b5r) {
z80c_addf_tbl[i] |= B5F;
z80c_subf_tbl[i] |= B5F;
}
if(hr) {
z80c_addf_tbl[i] |= B3F;
z80c_subf_tbl[i] |= B3F;
}
if((c1 && c2) || (!cr && (c1 || c2))) z80c_addf_tbl[i] |= CF;
if((h1 && h2) || (!hr && (h1 || h2))) z80c_addf_tbl[i] |= HF;
if((!c1 && !c2 && cr) || (c1 && c2 && !cr)) z80c_addf_tbl[i] |= PVF;
if((c2 && cr) || (!c1 && (c2 || cr))) z80c_subf_tbl[i] |= CF;
if((h2 && hr) || (!h1 && (h2 || hr))) z80c_subf_tbl[i] |= HF;
if((!c2 && !cr && c1) || (c2 && cr && !c1)) z80c_subf_tbl[i] |= PVF;
z80c_subf_tbl[i] |= NF;
}
#ifdef PROCP
TAB(incf_tbl) = z80c_incf_tbl;
TAB(decf_tbl) = z80c_decf_tbl;
TAB(addf_tbl) = z80c_addf_tbl;
TAB(subf_tbl) = z80c_subf_tbl;
TAB(orf_tbl) = z80c_orf_tbl;
PORT(inports) = PRNM(inports);
PORT(outports) = PRNM(outports);
#ifdef SPECT_MEM
SPECP(fe_inport_high) = SPNM(fe_inport_high);
#endif
#endif
}
int PRNM(step)(int tc)
{
#ifdef PROCP
Z80 *z80p;
z80p = &PRNM(proc);
#endif
DANM(tc) = tc;
DANM(rl7) = RR & 0x80;
if(DANM(haltstate)) {
register int nn;
nn = (DANM(tc) - 1) / 4 + 1;
DANM(tc) -= 4 * nn;
RR += nn;
}
else do {
register int nextop;
#ifdef DEBUG_Z80
debug_z80();
#endif
nextop = *PCP;
PC++;
#ifdef PROCP
z80p = (*z80c_op_tab[nextop])(z80p);
#else
(*z80c_op_tab[nextop])();
#endif
RR++;
} while(DANM(tc) > 0);
RR = (RR & 0x7F) | DANM(rl7);
return DANM(tc);
}