public void SetReg(WD93REG reg, byte value)
{
long tact = m_cpu.Tact;
if (LogIO)
{
LogAgent.Debug(
"WD93 {0} <== #{1:X2} [PC=#{2:X4}, T={3}]",
reg,
value,
m_cpu.regs.PC,
tact);
}
process(tact);
switch (reg)
{
case WD93REG.CMD: // COMMAND/STATUS
LedDiskIO = true;
// force interrupt
if ((value & 0xF0) == 0xD0)
{
int cond = value & 0xF;
next = tact;
idx_cnt = 0;
idx_tmo = next + 15 * Z80FQ / FDD_RPS; // 15 disk turns
cmd = value;
if (cond == 0)
{
state = WDSTATE.S_IDLE; rqs = BETA_STATUS.NONE;
status &= ~WD_STATUS.WDS_BUSY;
break;
}
if ((cond & 8) != 0) // Immediate Interrupt
{
state = WDSTATE.S_IDLE; rqs = BETA_STATUS.INTRQ;
status &= ~WD_STATUS.WDS_BUSY;
break;
}
if ((cond & 4) != 0) // Index Pulse (unimplemented yet)
{
state = WDSTATE.S_IDLE; rqs = BETA_STATUS.INTRQ;
status &= ~WD_STATUS.WDS_BUSY;
break;
}
if ((cond & 2) != 0) // Ready to Not-Ready Transition (unimplemented yet)
{
state = WDSTATE.S_IDLE; rqs = BETA_STATUS.INTRQ;
status &= ~WD_STATUS.WDS_BUSY;
break;
}
if ((cond & 1) != 0) // Not-Ready to Ready Transition (unimplemented yet)
{
state = WDSTATE.S_IDLE; rqs = BETA_STATUS.INTRQ;
status &= ~WD_STATUS.WDS_BUSY;
break;
}
break;
}
if ((status & WD_STATUS.WDS_BUSY) != 0)
break;
cmd = value;
next = tact;
status |= WD_STATUS.WDS_BUSY;
rqs = BETA_STATUS.NONE;
idx_cnt = 0;
idx_tmo = long.MaxValue;
//-----------------------------------------------------------------------
if ((cmd & 0x80) != 0) // read/write command
{
// abort if no disk
if ((status & WD_STATUS.WDS_NOTRDY) != 0)
{
state2 = WDSTATE.S_IDLE;
state = WDSTATE.S_WAIT;
next = tact + Z80FQ / FDD_RPS;
rqs = BETA_STATUS.INTRQ;
break;
}
// continue disk spinning
if (fdd[drive].motor > 0 || wd93_nodelay)
fdd[drive].motor = next + 2 * Z80FQ;
state = WDSTATE.S_DELAY_BEFORE_CMD;
break;
}
// else seek/step command
state = WDSTATE.S_TYPE1_CMD;
break;
case WD93REG.TRK:
track = value;
break;
case WD93REG.SEC:
sector = value;
break;
case WD93REG.DAT:
LedDiskIO = true;
data = value;
rqs &= ~BETA_STATUS.DRQ;
status &= ~WD_STATUS.WDS_DRQ;
break;
case WD93REG.SYS:
LedDiskIO = true;
//system = value;
drive = value & 3;
side = 1 & ~(value >> 4);
fdd[drive].HeadSide = side;
//seldrive->t.clear();
fdd[drive].t = fdd[drive].CurrentTrack;
if ((value & (int)WD_SYS.SYS_RST) == 0) // reset
{
status = WD_STATUS.WDS_NOTRDY;
rqs = BETA_STATUS.INTRQ;
fdd[drive].motor = 0;
state = WDSTATE.S_IDLE;
idx_cnt = 0;
idx_status = 0;
#if NO_COMPILE // move head to trk00
steptime = 6 * (Z80FQ / 1000); // 6ms
next += 1*Z80FQ/1000; // 1ms before command
state = S_RESET;
//seldrive->track = 0;
#endif
}
else if (((system ^ value) & (int)WD_SYS.SYS_HLT) != 0) // hlt 0->1
{
if ((status & WD_STATUS.WDS_BUSY) == 0)
{
idx_cnt++;
}
}
system = value;
break;
default:
throw new Exception("WD1793.SetReg: Invalid register");
}
process(tact);
}
public byte GetReg(WD93REG reg)
{
long tact = m_cpu.Tact;
process(tact);
byte value = 0xFF;
switch (reg)
{
case WD93REG.CMD: // COMMAND/STATUS #1F
LedDiskIO = true;
rqs &= ~BETA_STATUS.INTRQ;
value = (byte)status;
if ((system & (int)WD_SYS.SYS_HLT) == 0)
value &= (byte)(value & (int)~WD_STATUS.WDS_HEADL);
if (!fdd[drive].Present)
value = (byte)(value & ~(byte)WD_STATUS.WDS_INDEX); // No disk emulation
break;
case WD93REG.TRK: // #3F
value = track;
break;
case WD93REG.SEC: // #5F
value = sector;
break;
case WD93REG.DAT: // #7F
LedDiskIO = true;
status &= ~WD_STATUS.WDS_DRQ;
rqs &= ~BETA_STATUS.DRQ;
value = data;
break;
case WD93REG.SYS: // #FF
LedDiskIO = true;
value = (byte)((byte)rqs | 0x3F);
break;
default:
throw new InvalidOperationException();
}
if (LogIO)
{
LogAgent.Debug(
"WD93 {0} ==> #{1:X2} [PC=#{2:X4}, T={3}]",
reg,
value,
m_cpu.regs.PC,
tact);
}
return value;
}
