GCC HyperDrive HELP

[VCSMaster]

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.

 

[ESM-NL]

I have a hard drive laying around which came originally from a Mac Plus Hyperdrive 20 system. I'm not sure if this is the drive you looking for. I only can find this on the disc:
Miniscribe Corporation
Model 8425
Serial No. CA 107832

If you are interested, let me know.

 

[VCSMaster]

I have a hard drive laying around which came originally from a Mac Plus Hyperdrive 20 system. I'm not sure if this is the drive you looking for. I only can find this on the disc:
Miniscribe Corporation
Model 8425
Serial No. CA 107832

If you are interested, let me know.

No, that is a Miniscribe 8425, not the MMI 112 I need the ROM from. The drive I am looking for is in the HyperDrive 10, as mentioned in my post.

 

[superjer2000]

Not helpful for your situation, but I also have a strong affinity for old hard disk mechanisms. If you are able to share some pics and information regarding your collection at some point that would be awesome!

 

[superjer2000]

Also it looks like @JDW has an MMI-112 as he did a recap on it.

 

[VCSMaster]

Not helpful for your situation, but I also have a strong affinity for old hard disk mechanisms. If you are able to share some pics and information regarding your collection at some point that would be awesome!

Parts of it are already on a YouTube channel I started just to document them. Here it is, if you'd like: https://www.youtube.com/@TheDiskMaster
I also have a Discord server and am working on adding a photo museum to my website.

I have actually personally spoken with JDW in the past via email, though from what we discussed it seems that he is very busy with some personal matters right now. I have not heard from him in a while as a result.

 

[VCSMaster]

Also it looks like @JDW has an MMI-112 as he did a recap on it.

I was able to get in touch with him and we were able to recently get ahold of a complete ROM image from his drive. Sadly, it did not fix my prototype drive, something else is still wrong with it. It may have hardware differences from production drives.

He did mention that it was okay for me to share the EPROM binary, hopefully preserving it for others, so I have attached it to this post.

 

[jmacz]

I don’t have any info to share as I don’t own the hyperdrive but asking out of pure curiosity, did the rom image allow you to restore the second drive you picked up? Is that one working now?

 

[VCSMaster]

I don’t have any info to share as I don’t own the hyperdrive but asking out of pure curiosity, did the rom image allow you to restore the second drive you picked up? Is that one working now?

I have not removed the IC from the drive yet. It is not socketed, so it is not as easy to swap.

 

[olivercampion]

I have a hard drive laying around which came originally from a Mac Plus Hyperdrive 20 system. I'm not sure if this is the drive you looking for. I only can find this on the disc:
Miniscribe Corporation
Model 8425
Serial No. CA 107832

If you are interested, let me know.

You don’t by any chance have the Hyperdrive controller board still do you? I think mine is faulty

 

[ESM-NL]

You don’t by any chance have the Hyperdrive controller board still do you? I think mine is faulty

Well, not at the moment of my reply. I did only have that drive.

Recently I bought Hyperdrive parts on eBay and now it's nearly complete. Only need a Mac Plus, but I'm working on that.

 

[olivercampion]

Well, not at the moment of my reply. I did only have that drive.

Recently I bought Hyperdrive parts on eBay and now it's nearly complete. Only need a Mac Plus, but I'm working on that.

Ah, OK, thanks. Good luck with your Hyperdrive journey. This is as far as I've got

 

[VCSMaster]

You don’t by any chance have the Hyperdrive controller board still do you? I think mine is faulty

I do have the complete kit excluding the disk drive and manual. I would be happy to trade the box, the packing materials, the control board, etc, even a suitable replacement drive in exchange. Rodime RO352, Seagate ST125, Miniscribe 8425, your choice.

 

[olivercampion]

I do have the complete kit excluding the disk drive and manual. I would be happy to trade the box, the packing materials, the control board, etc, even a suitable replacement drive in exchange. Rodime RO352, Seagate ST125, Miniscribe 8425, your choice.

Ah, I’d have loved to take you up on that because I’m replacing my drive with an MFM emulator but I’m afraid my MiniScribe 20Mb 8425 MFM drive had suffered with an extreme case of stiction and the heads did not survive being freed. The heads have since been removed so the drive spins up freely and I was planning to use it for sound effects to give the Hyperdrive 512k Mac a more authentic sound when turning on.

 

[VCSMaster]

Ah, I’d have loved to take you up on that because I’m replacing my drive with an MFM emulator but I’m afraid my MiniScribe 20Mb 8425 MFM drive had suffered with an extreme case of stiction and the heads did not survive being freed. The heads have since been removed so the drive spins up freely and I was planning to use it for sound effects to give the Hyperdrive 512k Mac a more authentic sound when turning on.

Oh, dang. I've got a stack of about 30 Miniscribe 8425s laying around these days, what I am struggling to find is the MMI MM112 10MB driv ethat shipped with the HyperDrive.

 

[nathall]

Any chance you’d want to sell a handful of those? I’ve got a Kaypro I want to add a hard drive to.

 

[olivercampion]

Oh, dang. I've got a stack of about 30 Miniscribe 8425s laying around these days, what I am struggling to find is the MMI MM112 10MB drive that shipped with the HyperDrive.

If I ever see one, I'll let you know!

 

[VCSMaster]

Any chance you’d want to sell a handful of those? I’ve got a Kaypro I want to add a hard drive to.

Sure, any specific unit you're looking for? I believe I have the largest collection of vintage drives in North America. I definitely do not need the 30-50 8425s I have.