April 26, 2022
Callan MFM drive - data recovery
The 20M MFM hard drive from my old Callan refuses to be read by
the original disk controller.
My friend AJ has had great luck with the device by David Gesswein
that reads raw MFM data from the disk, and loaned me one for me
to experiment with.
Gesswein device
This is an amazing piece of work.
The Gesswein device does far more than I need it to do.
It will do the following:
- Read and recover data from an old drive.
- Emulate an MFM drive
- Includes a built in "UPS" based on supercapacitors
A package from AJ arrived 4-25-2022 with a Gesswein device,
an ailing BBB (beagleboard black) and a "Greaseweazle".
Greasweazle
This is like a Gesswein device, but for floppy disks.
It is based on a AT32F402 microcontroller, which is an ARM Cortex-M
running at 200 Mhz. This is apparently plenty fast for floppy disks.
There have been various other controllers used.
This is remarkably inexpensive. You can order one from Europe on Ebay, or from a seller
in the United States for about $30 (in Florida).
Feedback? Questions?
Drop me a line!
Tom's Computer Info / tom@mmto.org