Hello! I am primarily a collector of vintage hard disk drives, and I recently stumbled into owning an exceptionally rare prototype disk drive. The prototype is for a Microcomputer Memories Inc (MMI) MM-112, which was the standard hard disk with the GCC HyperDrive 10 kit sometimes installed in Macintosh 512k machines.
Sadly, the EPROM containing the firmware in the prototype has been damaged. The upper 4 bits of every byte are corrupt. Luckily, the production drives still include a ROM-less Z8 microcontroller, meaning their firmware is stored externally on a standard 2732 EPROM. In the hopes of imaging the firmware myself, I had bought the only HyperDrive I could get my hands on, which was the overpriced boxed kit on eBay. I paid a much more reasonable price for it than $600, but the drive wound up working. Sadly, in my attempts to image the EPROM myself, I appear to have damaged it. It behaves exactly the same as the prototype with the damaged EPROM.
In short, I either need another mechanism from a HyperDrive (or similar disk drive, compatible models are the MM-106, MM-112, MM-206, MM-212), or I need some kind individual to image the firmware for me. In this way, I could repair both drives.
I would be willing to pay a premium for a working example of a mechanism, and I'd even be willing to take a shot at known bad or untested drives. I would also be willing to pay someone directly to image the EPROM themselves and send me the binary.
I don't own a 512k into which to install the HyperDrive board itself, so I would be willing to sell/trade the setup for just the disk drive.
Sadly, the EPROM containing the firmware in the prototype has been damaged. The upper 4 bits of every byte are corrupt. Luckily, the production drives still include a ROM-less Z8 microcontroller, meaning their firmware is stored externally on a standard 2732 EPROM. In the hopes of imaging the firmware myself, I had bought the only HyperDrive I could get my hands on, which was the overpriced boxed kit on eBay. I paid a much more reasonable price for it than $600, but the drive wound up working. Sadly, in my attempts to image the EPROM myself, I appear to have damaged it. It behaves exactly the same as the prototype with the damaged EPROM.
In short, I either need another mechanism from a HyperDrive (or similar disk drive, compatible models are the MM-106, MM-112, MM-206, MM-212), or I need some kind individual to image the firmware for me. In this way, I could repair both drives.
I would be willing to pay a premium for a working example of a mechanism, and I'd even be willing to take a shot at known bad or untested drives. I would also be willing to pay someone directly to image the EPROM themselves and send me the binary.
I don't own a 512k into which to install the HyperDrive board itself, so I would be willing to sell/trade the setup for just the disk drive.
