Trying a different disk this time, after abandoning the last drive I talked about here, and doing some successful reads and emulations between then and now...
Now working with a Computer Memories, Inc Model CM5410-C Drive.
Doing an analyze looks quite successful:
root@beaglebone:~/mfm# ./mfm_read -v
Board revision C detected
Version 2.25
Drive must be between 1 and 4
root@beaglebone:~/mfm# ./mfm_read -a
Board revision C detected
Found drive at select 2
Returning to track 0
Drive RPM 3602.0
Matches count 63 for controller CONVERGENT_AWS
Header CRC: Polynomial 0x1021 length 16 initial value 0x0
Sector length 256
Data CRC: Polynomial 0x1021 length 16 initial value 0x0
Selected head 8 found 0, last good head found 3
Read errors trying to determine sector numbering, results may be in error
Number of heads 4 number of sectors 32 first sector 1
Interleave (not checked): 14 27 8 21 2 15 28 9 22 3 16 29 10 23 4 17 30 11 24 5 18 31 12 25 6 19 32 13 26 7 20 1
Drive supports buffered seeks (ST412)
Found cylinder 255 expected 256
Found cylinder 255 expected 257
Stopping end of disk search due to mismatching cylinder count
Number of cylinders 256, 8.4 MB
Command line to read disk:
--format CONVERGENT_AWS --sectors 32,1 --heads 4 --cylinders 256 --header_crc 0x0,0x1021,16,0 --data_crc 0x0,0x1021,16,0 --sector_length 256 --retries 50,4 --drive 2 --begin_time 460000
However, when I try to do a raw transitions file read, I get this on every single cylinder and every single head over and over again, until 41.
Retries failed cyl 41 head 2
Ran out of data on sector index 32, try reading with --begin_time 537000
Bad sectors on cylinder 41 head 2: 1
Ran out of data on sector index 32, try reading with --begin_time 537000
Ran out of data on sector index 32, try reading with --begin_time 536000
Ran out of data on sector index 32, try reading with --begin_time 536000
Ran out of data on sector index 32, try reading with --begin_time 537000
Ran out of data on sector index 32, try reading with --begin_time 536000
Ran out of data on sector index 32, try reading with --begin_time 537000
Ran out of data on sector index 32, try reading with --begin_time 537000
Ran out of data on sector index 32, try reading with --begin_time 537000
Ran out of data on sector index 32, try reading with --begin_time 536000
Ran out of data on sector index 32, try reading with --begin_time 536000
Ran out of data on sector index 32, try reading with --begin_time 537000
Ran out of data on sector index 32, try reading with --begin_time 537000
Ran out of data on sector index 32, try reading with --begin_time 537000
Ran out of data on sector index 32, try reading with --begin_time 536000
Ran out of data on sector index 32, try reading with --begin_time 537000
Ran out of data on sector index 32, try reading with --begin_time 537000
Ran out of data on sector index 32, try reading with --begin_time 537000
Ran out of data on sector index 32, try reading with --begin_time 536000
Ran out of data on sector index 32, try reading with --begin_time 537000
Ran out of data on sector index 32, try reading with --begin_time 537000
Ran out of data on sector index 32, try reading with --begin_time 537000
Failed to write word to transition file 16285
Then I guess it finally gives up on cyl 41 head 2 I guess...
So, since it is perfectly consistent on every single cylinder & head, is it possible that the drive was just formatted so that there's nothing past "sector index 32"? And really the drive is fine, but the reader program is expecting a more factory-standard format/use than what we have?
The drive is out of a Convergent Technologies AWS. I've never had one of these this old before, so this is a first for me. And I would guess for anyone, as I've never seen anyone try to restore any of the CT AWS/IWS machines. Only NGENs which were the upgrade to the AWS.
I've uploaded the raw transitions file that was created by this process, in case analysis of it is helpful. It can be downloaded here:
Thoughts & Ideas?
Thanks, David & Everyone!
Best
AJ