Fixed failing to read NEC drive.

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d...@pdp8online.com

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Jun 4, 2023, 10:40:45 AM6/4/23
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I found that reading NEC D5124 drive failed with this sequence of messages. Drive uses stepper motor for head positioning.

Found drive at select 2
Command 7 fault 300 status 30
Write fault
Seek complete
Not Index
Not Ready
Drive selected 

The issue is the drive generates a write fault if a head that isn't present is selected. There was a bug in the code where the head select state wasn't set before checking if the drive is ready so was invalid for the drive. Analyze will also select an invalid head while trying to determine the number of heads. I have added code to handle the error.

I have release v3.0 which fixes this. If you had gotten the write fault error trying to read a drive try rereading the drive and see if it now works. If you had gotten the not ready fault only may be worth retrying also. If it gets further but still errors out let me know.

I don't know of other makes of drives that act this way but their may be.

Updated code on web site and github.

d...@pdp8online.com

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Jun 4, 2023, 11:23:15 AM6/4/23
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Released 3.01. Decided I should fix the head signal initial state in setup_mfm_read also. Probably doesn't make any real difference.

Xolod

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Jun 4, 2023, 1:51:12 PM6/4/23
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I confirm the work of the NEC D5124 disk with the new version!

воскресенье, 4 июня 2023 г. в 18:23:15 UTC+3, d...@pdp8online.com:
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