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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 This disk uses 35 (vs 70) tracks of 16 (vs 32) sectors
of 137 bytes each. 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" #include "altairz80_defs.h"
@ -529,9 +532,15 @@ int32 dsk10(const int32 port, const int32 io, const int32 data) {
else { else {
current_sector[current_disk] = 0xff; /* reset internal counters */ current_sector[current_disk] = 0xff; /* reset internal counters */
current_byte[current_disk] = 0xff; current_byte[current_disk] = 0xff;
current_flag[current_disk] = data & 0x80 ? 0 /* disable drive */ : if (data & 0x80) /* disable drive? */
(current_track[current_disk] == 0 ? 0x5a /* enable: head move true, track 0 if there */ : current_flag[current_disk] = 0; /* yes, clear all flags */
0x1a); /* enable: head move true */ 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 */ 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' */ 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] &= 0xfb; /* turn off 'head loaded' bit */
current_flag[current_disk] &= 0x7f; /* turn off 'read data available' */ current_flag[current_disk] &= 0x7f; /* turn off 'read data available' */
current_sector[current_disk] = 0xff; current_sector[current_disk] = 0xff;