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AltairZ80: SIO: Support 32-bits for setFCBAddressCmd.

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The M68K requires more than 16-bits for the FCB address.  Expand to
32-bits.
This commit is contained in:
Howard M. Harte 2022-11-23 20:43:23 -08:00 • committed by Paul Koning
parent 87581b865f
commit 7cca92ce28
1 changed files with 32 additions and 4 deletions
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36
AltairZ80/altairz80_sio.c
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@ -1768,19 +1768,45 @@ static int32 simh_out(const int32 port, const int32 data) {
}
break;
case setFCBAddressCmd:
if (setFCBAddressPos == 0) {
/* SETFCBADDR command always takes four bytes:
* Byte Z80 8086 68000 32-Bit Address Space (future)
* ---- ----- ----- ----- -----------------------------
* 1 A7:0 A7:0 A7:0 A7:0
* 2 A15:8 A15:8 A15:8 A15:8
* 3 0 DS A23:16 A23:16
* 4 0 0 0 A31:24
* For 8086, the FCB address is updated by writing the fourth
* byte, using the offset A15:0 from the first two bytes and
* taking the segment from the CPU's DS register.
*/
switch (setFCBAddressPos) {
case 0: /* Address 7:0 */
FCBAddress = data;
setFCBAddressPos = 1;
}
else {
setFCBAddressPos++;
break;
case 1: /* Address 15:8 */
FCBAddress |= (data << 8);
setFCBAddressPos++;
break;
case 2: /* Address 23:16 */
FCBAddress |= (data << 16);
setFCBAddressPos++;
break;
default: /* Address 31:24 */
if (chiptype == CHIP_TYPE_8086) {
/* Mask the offset to 16-bits and add in the segment from DS register. */
setViewRegisters();
FCBAddress &= 0xFFFF;
FCBAddress += (DS_S << 4);
sim_debug(CMD_MSG, &simh_device, "SIMH: " ADDRESS_FORMAT
" FCBAddress=0x%05x, DS=0x%04x\n", PCX, FCBAddress, DS_S);
} else {
FCBAddress |= (data << 24);
sim_debug(CMD_MSG, &simh_device, "SIMH: " ADDRESS_FORMAT
" FCBAddress=0x%08x\n", PCX, FCBAddress);
}
setFCBAddressPos = lastCommand = 0;
break;
}
break;
@ -1919,6 +1945,8 @@ static int32 simh_out(const int32 port, const int32 data) {
markTimeSP = 0;
lastCommand = 0;
deleteNameList();
setFCBAddressPos = 0;
FCBAddress = CPM_FCB_ADDRESS;
break;
case showTimerCmd: /* show time difference to timer on top of stack */