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Slow down sector read/write speed on AT Fixed Disk Adapter. Fixes OS/2 v1.0 hard drive formatter.

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This commit is contained in:
SarahW 2019-05-13 19:39:56 +01:00
commit 1f57a70a21
1 changed files with 10 additions and 2 deletions
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12
src/mfm_at.c
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@ -21,6 +21,14 @@
#define IDE_TIME (TIMER_USEC*10)//(5 * 100 * (1 << TIMER_SHIFT))
/*Rough estimate - MFM drives spin at 3600 RPM, with 17 sectors per track,
meaning (3600/60)*17 = 1020 sectors per second, or 980us per sector.
This is required for OS/2 on slow 286 systems, as the hard drive formatter
will crash with 'internal processing error' if write sector interrupts are too
close in time*/
#define SECTOR_TIME (TIMER_USEC * 980)
#define STAT_ERR 0x01
#define STAT_INDEX 0x02
#define STAT_CORRECTED_DATA 0x04
@ -313,7 +321,7 @@ void mfm_writew(uint16_t port, uint16_t val, void *p)
{
mfm->pos = 0;
mfm->status = STAT_BUSY;
timer_set_delay_u64(&mfm->callback_timer, 6*IDE_TIME);
timer_set_delay_u64(&mfm->callback_timer, SECTOR_TIME);
}
}
@ -382,7 +390,7 @@ uint16_t mfm_readw(uint16_t port, void *p)
{
mfm_next_sector(mfm);
mfm->status = STAT_BUSY;
timer_set_delay_u64(&mfm->callback_timer, 6*IDE_TIME);
timer_set_delay_u64(&mfm->callback_timer, SECTOR_TIME);
}
}
}