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CP/M and FreHD (or other SD card HD based device)

Patrick.B (TTR)

Experienced Member
Joined
May 11, 2011
Messages
491
Location
Houston, Texas, USA
Has anyone gotten CP/M PLUS (also known as CP/M v3.0) on a Z80 Based machine and FreHD (or other SD card HD based device) to work?
I cannot get it to recognise the presence of the hard drive, but the hardware is functional as I can see, format and use it on other O/S.
any clue?
 
I was actually thinking along these lines recently. I have a FreHD on my TRS-80 Model 4P.

I wanted to research whether a FreHD would be compatible with my Osborne Executive.
 
I know this is an older thread - but I would like to find something like FreHD for the Osborne as well - anyone have an idea where I can look - or if it exists?
 
Seems like much of the GIDE portion is not active any longer? Anyone have anything that could help? I will check to see if the CPU is socketed..
 
I had a glance at the detailed stuff. The IEE488/Centronics is actually just an 6821 PIA, so I think you could just wire a 5v SD card adapter to a connector and bitbang that. Wouldn't be very fast. Assuming all the lines are broken out suitably (not found a schematic at the moment) then it's actually enough lines to drive a compact flash card providing you've got a suitable 5v source to tap.
 
People make GIDE cards as and when they need them. It's an open design that is fairly easy to produce. The better option but more software involved is probably the IEE488 (aka HP-IB / GP-IB). That's quite a fast interface, external and you can talk to it with an Arduino and a bit of logic. Nothing off the shelf for a CP/M machine though, although there are for HP 9845's and the like where the original GPIB drives are like unicorn droppings.
 
I'm using a GOTEK with my Osborne - Is it something that needs the extra speed? For a HDD other than what a computer is designed to use to operate under CP/M it's going to need to be accessible from the BIOS. You can update the bios, interface with it or write applications to handle the files like Myke is in his thread.
Also, if it's using a PC format, something will have to translate it to CP/M disk format, which involves more than just a bios, as something is going to need to translate allocations. I'm not familiar with the FREHD so I don't know if it does that.

But the Gotek is fast enough for working with an old Osborne :) At least for my purposes.

Regards
David
 
Which Gotek configuration did you use for your Osborne? This looks like it might be the best option at this time as near as I can tell. I'm ok with that. You wouldn't happen to have a link for it would you? Thank you.
 
You can get a cable adapter if you want to use the same cable, or you can make up a cable and cut out the wires that shouldn't go to the gotek, as well as pulling the power wire from the cable to power the Gotek.

There's a thread on getting it working here: https://forum.vcfed.org/index.php?threads/osborne-1-gotek-floppy-emulator-success.57809/

It shows how to wire up the cable, or you can just order the adapters and populate them. I got three adapters, and then made the cable anyway while I waited.

The Gotek can replace Drive A or Drive B since you can select which drive is which on boot with the Osborne 1 ( Shift = if I recall correctly to make B: A: )

Regards
David
 
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