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AltairZ80: Improved Altair Minidisk support from Mike Douglas

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This commit is contained in:
Peter Schorn 2014-07-05 09:44:20 +02:00
parent f961a98ba9
commit a0c978f5f7
1 changed files with 14 additions and 5 deletions
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19
AltairZ80/altairz80_dsk.c
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@ -108,9 +108,12 @@
----------------------------------------------------------
5/22/2014 - Updated by Mike Douglas to support the Altair Mini-Disk.
5/22/2014 - Updated by Mike Douglas to support the Altair Minidisk.
This disk uses 35 (vs 70) tracks of 16 (vs 32) sectors
of 137 bytes each.
6/30/2014 - When the disk is an Altair Minidisk, load the head as
soon as the disk is enabled, and ignore the head
unload command (both like the real hardware).
*/
#include "altairz80_defs.h"
@ -529,9 +532,15 @@ int32 dsk10(const int32 port, const int32 io, const int32 data) {
else {
current_sector[current_disk] = 0xff; /* reset internal counters */
current_byte[current_disk] = 0xff;
current_flag[current_disk] = data & 0x80 ? 0 /* disable drive */ :
(current_track[current_disk] == 0 ? 0x5a /* enable: head move true, track 0 if there */ :
0x1a); /* enable: head move true */
if (data & 0x80) /* disable drive? */
current_flag[current_disk] = 0; /* yes, clear all flags */
else { /* enable drive */
current_flag[current_disk] = 0x1a; /* move head true */
if (current_track[current_disk] == 0) /* track 0? */
current_flag[current_disk] |= 0x40; /* yes, set track 0 true as well */
if (sectors_per_track[current_disk] == MINI_DISK_SECT) /* drive enable loads head for Minidisk */
current_flag[current_disk] |= 0x84;
}
}
return 0; /* ignored since OUT */
}
@ -618,7 +627,7 @@ int32 dsk11(const int32 port, const int32 io, const int32 data) {
current_flag[current_disk] |= 0x80; /* turn on 'read data available' */
}
if (data & 0x08) { /* head unload */
if ((data & 0x08) && (sectors_per_track[current_disk] != MINI_DISK_SECT)) { /* head unload */
current_flag[current_disk] &= 0xfb; /* turn off 'head loaded' bit */
current_flag[current_disk] &= 0x7f; /* turn off 'read data available' */
current_sector[current_disk] = 0xff;