void DamGetHL(int Ext)
{
// Get the HL pointer, or if extended the IX/IY pointer
if (Ext!=0xdd && Ext!=0xfd) Ext=0;
if (Ext==0) DamGet16("di",2,Ext);
else ot(" add di,%s\n",DamLoc16(2,Ext));
}
int Damf_ED_101x_x00x(unsigned int op)
{
// ED 101r s000 Transfer bytes from (hl) to (de)
// ED 101r s001 compare bytes at (hl)
// r -> once/repeat s -> ++/--
// e.g ED 1011 0000 ldir
DamOpStart(op);
ot(" ; cp/ld/i/d/r\n");
DamGet16("di",2,0);
ot(" DAM_READ8\n");
if (op&1)
{
// cp
ot(" mov dh,ah\n");
ot(" and dh,0x01\n");
ot(" cmp al,dl\n");
ot(" lahf\n");
ot(" and ah,0xd0 ; SZ-H ----\n");
ot(" or ah,0x02 ; SZ-H --N-\n");
ot(" or ah,dh ; SZ-H --NC\n");
ot(" ; Now work out A-(HL)-H: for bits 5 and 3\n");
ot(" sub dl,al\n");
ot(" neg dl ; A-(HL)\n");
ot(" mov dh,ah\n");
ot(" ror dh,4\n");
ot(" and dh,0x01\n");
ot(" sub dl,dh ; A-(HL)-H\n");
}
else
{
// ld
DamGet16("di",1,0);
ot(" DAM_WRITE8\n");
ot(" and ah,0xc1 ; SZ-H --NC (SZC preserved, H=0, N=0)\n");
ot(" ; Now work out A+(HL): for bits 5 and 3\n");
ot(" add dl,al\n");
}
ot(" xor dh,dh\n");
ot(" test dl,0x02 ; Bit 5 is copied from bit 1\n");
ot(" setnz dh\n");
ot(" rol dh,5\n");
ot(" or ah,dh ; SZ5H --NC\n");
ot(" mov dh,dl\n");
ot(" and dh,0x08\n");
ot(" or ah,dh ; SZ5H 3-NC\n");
if ((op&1)==0)
{
ot(" ; Update DE\n");
if (op&8) ot(" dec "); else ot(" inc ");
ot("%s\n",DamLoc16(1,0));
}
ot(" ; Update HL\n");
if (op&8) ot(" dec "); else ot(" inc ");
ot("%s\n",DamLoc16(2,0));
ot(" ; Update BC\n");
ot(" dec %s\n",DamLoc16(0,0));
ot("; Check if BC==0\n");
ot(" xor dh,dh\n");
ot(" test %s,0xffff\n",DamLoc16(0,0));
ot(" setnz dh\n");
ot(" rol dh,2\n");
ot(" or ah,dh ; SZ5H 3VNC\n");
if (op&0x10)
{
static int Lab=0;
ot("; Stop repeating if BC==0\n");
ot(" test ah,0x04 ; ---- -V--\n");
ot(" jz Done%d\n",Lab);
if (op&1)
{
ot("; Stop repeating if a-(HL) == 0\n");
ot(" test ah,0x40 ; -Z-- ----\n");
ot(" jnz Done%d\n",Lab);
}
ot(" ; Repeat instruction\n");
ot(" INC_R\n");
DamAddPc(-2);
DamOpDone(17,0);
ot("Done%d:\n",Lab++);
}
DamOpDone(12,0);
return op;
}
int DamPut16(char *From,int r,int Ext)
{
// Put register r from
ot(" mov %s,%s\n",DamLoc16(r,Ext),From);
return 0;
}
int DamGet16(char *To ,int r,int Ext)
{
// Get register r into To
ot(" mov %s,%s\n",To,DamLoc16(r,Ext));
return 0;
}