3 Nov
2025
3 Nov
'25
2:16 p.m.
I just purchased an old Gimix computer (now if only I can get it from
Orlando to Chicago before my friend goes down there for Christmas).
It has an OMTI 20C-1 MFM hard disk controller with a IMI 5018 19MB hard
disk drive in it.
It has been recommended that i don't even turn the system on with the
hard drive in it but rather I remove the drive an I send the IMI 18MB
drive directly to a recovery house for data recovery.
What do you all think about that?
Do any of you have any experience with a recovery service for MFM ST-506
Drives?
Also, does anyone have a half height 30MB or larger MFM ST-506
compatible drive that will work with the OMTI 20C controller for sale at
a reasonable price. Preferably one that at least spins up.
Also, does anyone have the syquest 5MB removable MFM drive and some
cartridges, also at a reasonable price.
My goal is to equip the Gimix with the following drives:
* 2 80 Track DS/DD 5 1/4" half high floppy drives (in the system)
* 2 77 Track DS/DD 8" Floppies (I have these in need of cleaning up,
just not in a Gimix case)
* 1 18 to 50MB MFM half high MFM Hard Drive (system has a full high
18MB drive)
* 1 6MB Syquest removable cartridge drive half high (I need to find)
At some point I would love to expand the RAM to as close to 1MB as I can
(CPU/Motherboard supports up to 1016KB) and add a 3 or 4 port
intelligent serial card and an intelligent parallel card (I'm sure these
cards are unobtanium).
Thank you all for your help
If you have a dual 8" drive setup (double sided drives, and enclosure)
that you need a good home for, please let me know.
I'm in the Chicago Area.
Thanks,
Mike
bitwiz(a)12bitsbest.com
3 Nov
3 Nov
5:34 p.m.
On Nov 3, 2025, at 5:16 PM, Mike Katz via cctalk
<cctalk(a)classiccmp.org> wrote:
I just purchased an old Gimix computer (now if only I can get it from Orlando to Chicago
before my friend goes down there for Christmas).
It has an OMTI 20C-1 MFM hard disk controller with a IMI 5018 19MB hard disk drive in it.
It has been recommended that i don't even turn the system on with the hard drive in
it but rather I remove the drive an I send the IMI 18MB drive directly to a recovery house
for data recovery.
Why would you do that? What would you expect such a shop to be able to do with the drive?
If a drive is known to be bad, and you want to do a desperate (and expensive) attempt to
recover parts of it, this is how it's done. But if it isn't known bad, it seems
like a very expensive option just to read an old drive.
Also, if the format is obscure enough, you may not be able to find a data recovery shop
that knows it. But if you connect it to a Dave Gesswein MFM emulator, it can slurp the
waveforms right off the drive for safekeeping. Once that is done, you can use the
captured data with the emulator and not have to run the drive again. Or you can convert
the low level format to extract the data, if it is a known format. If it isn't a
known format, you then have an interesting exercise to reverse engineer how the disk is
encoded and teach Dave's software to handle that format. It's pretty much
universal, capable of coping with just about anything that is MFM.
paul
4 Nov
4 Nov
12:26 a.m.
On 11/3/25 23:16, Mike Katz via cctalk wrote:
It has an OMTI 20C-1 MFM hard disk controller with a IMI 5018 19MB hard disk drive in it.
The evidence is anecdotal, I know, but I recovered the contents of 5 40 year old IMI5019
harddisks used in ETH Lilith computers : all 5 were fully functional and had zero defects.
I used David Gesswein's MFM reader, the Lilith uses a WD1001-05 derivative as the
diskcontroller.
5 p.m.
FWIW, those drives (IMI 5018/5020 were used in Cromemco hard disk systems,
but with a different logic board, so if you had a bad IMI interface drive
you could replace the drive with an MFM version.
In the other direction you could convert an IMI I/F drive to an MFM drive;
in fact, Cromemco sold the MFM PCB as a conversion kit.
They were also used by Corvus in their Apple computer and even the
Synclavier.
On Tue, Nov 4, 2025 at 10:43 AM jos via cctalk <cctalk(a)classiccmp.org>
wrote:
On 11/3/25 23:16, Mike Katz via cctalk wrote:
The evidence is anecdotal, I know, but I recovered the contents of 5 40
year old IMI5019 harddisks used in ETH Lilith computers : all 5 were fully
functional and had zero defects.
I used David Gesswein's MFM reader, the Lilith uses a WD1001-05 derivative
as the diskcontroller.
It has an OMTI 20C-1 MFM hard disk controller with a IMI 5018 19MB hard
disk drive in it.
10
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4 comments
5 participants
participants (5)
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Fred Cisin -
jos -
Mike Katz -
Mike Stein -
Paul Koning