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Basic MFM drive emulator?

geneb

geneb

Veteran Member
Joined
Aug 19, 2003
Messages
525
Location
Graham, WA USA
I recently got a Kaypro 10. The drive has a few bad spots on it, and I suspect over time that this will only become worse. Even if a replacement drive could be found, it will still have the age issue going against it.

Are there any projects out there that seriously working on a device that can be plugged into standard MFM drive controllers like those found on the K10 and other vintage machines of the era?


g.
 
...and that's probably while I'll never solve this problem. I would honestly be shocked if there's actually $1k+ worth of components in the device.

It's really frustrating to not having the ability to design the electronics in order to solve this problem all the while knowing that the people that DO have the knowledge can't be bothered.

g.
 
It's not that--and my question was serious. There's a lot of work for one of these--most applications just replace the whole controller and drive. Replacing just the drive is quite a bit more complex. If the community of potential users is very small, there would seem to be very little payoff for whoever did all the hard work. Given the number of other projects, how would you convince someone to take the project on?

If this were my Kaypro, I'd find it easier to devise an add-in and patch the BIOS to use it.
 
The problem with the K10 and other similar-vintage systems is the controller board isn't a separate board - it's designed into the main board of the machine.

As far as I know, there's no drop-in solution for any of these old machines - I seem to recall something of a CPU socket based IDE controller, but there was so little interest, it never went anywhere. This blows my mind, especially with the apparently large population of the vintage computer crowd that could take advantage of this kind of device.

g.
 
geneb said:
The problem with the K10 and other similar-vintage systems is the controller board isn't a separate board - it's designed into the main board of the machine.
Click to expand...

I don't have a Kaypro 10 in front of me, but I seem to remember that it uses a separate WD1002 controller board connected to the main board by a 40 pin cable. Easy enough to replace that and the hard drive with something that behaves the same. ISTR that the same controller was used in some of the TRS-80 models.
 
The heath H-8/89 guys have come up with a Z-67 drive replacement, that plugs into the existing controller. I don't know what kind of drive was in those Z-67s though.. The vintage would be right for a MFM though.

*** EDIT ***
Turns out the Z-67 is a SASI drive, so probably no use to you... Neat piece of kit though...

http://koyado.com/Heathkit/Z67-IDE.html
 
Last edited:
Have you looked at the HxC Floppy Emulator: http://hxc2001.free.fr/floppy_drive_emulator/

It has both FM and MFM modes and seems to be good enough that it will even work in various synthesizers that used disks in a very non-standard fashion. Source code (including VHDL for the hardware bits) seems to be available, so maybe it could be modified to support MFM hard drives.
 
geneb said:
The problem with the K10 and other similar-vintage systems is the controller board isn't a separate board - it's designed into the main board of the machine.

As far as I know, there's no drop-in solution for any of these old machines - I seem to recall something of a CPU socket based IDE controller, but there was so little interest, it never went anywhere. This blows my mind, especially with the apparently large population of the vintage computer crowd that could take advantage of this kind of device.

g.
Click to expand...

Hi
On the N8VEM project we did make an "ECB to Z80 socket shim" board. It allows a machine to use an ECB board like DiskIO or PropIO with a pure socketed Z80 machine. In fact it was tested on a Kaypro 10 and a SpectraVideo 728. It seemed to work well however Chuck is right that the BIOS ROM would need to be patched to enable booting from such a device.

I have the PCBs although the project never really took off. It could easily add IDE, CF, SD or whatever to a "non-expandable" Z80 computer using off the shelf components.

http://n8vem-sbc.pbworks.com/w/browse/#view=ViewFolder&param=MINI ECB to Z80 socket adapters

Thanks!

Andrew Lynch
 
geneb said:
...and that's probably while I'll never solve this problem. I would honestly be shocked if there's actually $1k+ worth of components in the device.

It's really frustrating to not having the ability to design the electronics in order to solve this problem all the while knowing that the people that DO have the knowledge can't be bothered.

g.
Click to expand...

Hi,

I don't know who if anyone your comment is aimed at but there have been many "hobbyist" projects for with helping vintage computers. For every XT-IDE success there are many "flops" which died for lack of support.

http://www.vintage-computer.com/vcforum/showthread.php?22906-SCSI-1-to-from-IDE-drive-converter

http://www.vintage-computer.com/vcforum/showthread.php?25644-Another-floppy-simulator

and many others, etc

It is easy to say "why don't *they* do something" but it requires resources and time in addition to just skills. In the end, we are the *they*

I recommend to think twice before pointing fingers and declaring what other hobbyists should be doing in their free time as volunteers to make your hobby more enjoyable.

Thanks!

Andrew Lynch
 
madcrow said:
Have you looked at the HxC Floppy Emulator: http://hxc2001.free.fr/floppy_drive_emulator/

It has both FM and MFM modes and seems to be good enough that it will even work in various synthesizers that used disks in a very non-standard fashion. Source code (including VHDL for the hardware bits) seems to be available, so maybe it could be modified to support MFM hard drives.
Click to expand...

I doubt it--the bitrate of an ST506 hard drive is 5Mb/sec--20 times that of a 360K floppy. The logic of the HxC simply doesn't have the horsepower to do this.

However, replacing the WD1002 controller and associated hard drive is easy--the protocol is essentially 8 data bits+3 address bits plus a couple of handshaking bits. Any medium-speed microcontroller can handle that.
 
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