Copy 5" CPM disks - Melbourne

[HarryDoPECC]

Looking for some help in Melbourne, Aust

I'm in a downsize and a lot of my gear has gone to storage, but I want to help someone by giving him copies of 5" CPM disks. Would be good to be able to check and verify the contents, and an easy way would be if someone had a working CPM system nearby.

If anyone is willing to help, please PM me. 

Thanks!

[Stray Electron]

  5 inch or 5 1/4 inch?  It would probably help if said what kind of CPM system or what disk format since there are MANY different CPM formats and many of them use a different physical layout.

[HarryDoPECC]

OK, was a bit brief, intended to have more discuss offline if anyone was specifically interested.

Disks are 5.25 inch, belong to an obscure CPM system from Japan - details on my site https://dopecc.net/computers/ai/

I have got my machines to ROM boot but not OS boot due to drive defects (rubber, etc) and now they have gone to store.  I'm trying to help someone in another state who has found one which also boots to ROM, they want to try to go further.  I have some original boot disks to hand and would like to copy for them.  What I know for sure is 5.25 inch CPM 2.2.  I'm CPM-familiar but no guru so hoping to explore further details and the ability to make copies with anyone local who could help.

Happy to discuss for general information, or PM if better done off the board.
 

[Andy Chee]

A standard PC equipped with a 5.25" drive can read and write CPM disks using ImageDisk



(disk imaging discussion begins @41:00)

[guenthert]

  5 inch or 5 1/4 inch? 

   While there were 3" and (the later much more popular) 3.5" drives and disks, I'm confident in that there were no 5" floppys.

It would probably help if said what kind of CPM system or what disk format since there are MANY different CPM formats and many of them use a different physical layout.

    Indeed, the lack of a standard disk and filesystem format was probably one of the reasons why MSDOS won so fast.

   I believe that the BIOS of CP/M was also machine specific.  Best to get the boot disks from the manufacturer, else there will be some patching required.

[brucehoult]

Indeed, the lack of a standard disk and filesystem format was probably one of the reasons why MSDOS won so fast.

MSDOS didn't have a standard physical disk format any more than CP/M did. They both had standard logical structures.

In early days I used MSDOS on:

- DEC Rainbow with proprietary RX50 5.25-inch storing 400K. The machine could not format disks, you had to buy them pre-formatted! (also ran CP/M80 and CP/M86)

- Sanyo MBC-555. 320 KB FM (not MFM) floppies

Both of these machines ran standard MS-DOS but were not IBM-PC compatible in either software or floppy disks.

[Stray Electron]

The Sanyo MBC-550 and 555 were both MS-DOS compatible but they weren't IBM-PC compatible.  The slightly later software written specifically for the IBM-PC frequently ignored many of the BIOS calls and made calls to the hardware, such as the video memory, directly so that software could not run on a Sanyo. A good example was the Lotus 123 software; version 1A would run on the Sanyo but version 2.0 wouldn't.  The later versions of Sanyo MS-DOS could use 8, 9 or 10 sectored disks so they could read and write IBM's standard 360k 9-sectored disks.  The upgraded Sanyo MS-DOS sold by Michtron also supported 80 track drives so you could store as much as 800k per disk and you could have as many as four disk drives. 

  Starting around MS-DOS 3.1 you could add a statement to the Driver.sys file that would make the IBM-PC compatibles to default to an 8, 9 or 10 sectored  disk.

[Stray Electron]

   While there were 3" and (the later much more popular) 3.5" drives and disks, I'm confident in that there were no 5" floppys.

   And you'd be wrong. I used to have one in a MIL-STD-1553 bus analyzer.  I also had a disk drive in a Zenith Minisport computer that took 2" floppy disks.  I think that I still have a box full of disks for it around here somewhere. 

[HarryDoPECC]

Thanks all, good hint about ImageDisk.

As it turns out my FluxEngine https://cowlark.com/fluxengine/ was not too buried and I'm able to use this.  Had good results in the past so should work well again.