Backing up ST506 disks

From: Fred Cisin <>
Date: Mon Aug 4 13:57:00 2003

On Mon, 4 Aug 2003, [iso-8859-1] Jules Richardson wrote:
> I'm just wondering how to back up the hard drive (a 20MB MFM) in my Research
> Machines fileserver. The system runs CP/M, has a couple of floppy drives, and
> the hard disk is hooked up to a Xebec controller with a SASI bus linking it to
> the host controller in the fileserver.

Xebec controllers can usualy be cabled to two drives.
Why not connect another drive with similar geometry, and copy it?

> There are actually two problems:
> 1) Getting the data off the hard drive somehow (possibly via floppy) and
> being able to read it on another system (ideally a PC I suppose)

Are you up for the task of writing a file system handler for your PC?

> 2) Being able to rebuild the system if/when the hard drive fails.
> Thoughts on both are welcome! I don't have any kind of OS source media for the
> system, and it wouldn't surprise me if it isn't the only survivor :-( Maybe
> there are utilities on the system itself to recreate bootable OS media, but my
> knowledge of CP/M is a little lacking!

Start with a DIR.
Do you have PIP? SYSGEN?

> For my old SCSI systems I tend to hold a raw block-by-block backup image of the
> drive by putting the hard disk in a PC with Linux and dragging data off that
> way. If the drive fails and I can't get an identical replacement, a slightly
> larger drive still works with a little bit of wastage. Due to the relationship
> between the controller and drive using ST506 I gather things are probably a
> little more complex though...

Not much. Put an ST506 controller into a PC. ST506/412 was the defacto
standard on PCs until IDE. although most PC people erroneously refer to
the cabling and interface as "MFM". The controllers used by IBM in the XT
were made by Xebec.
Once you have a controller and drive in your PC, you can write the code to
read and write sectors to be able to copy a drive.
If you go a step further, and parse the DIRectory, then you could
selectively read and write sectors to be able to transfer files.
Received on Mon Aug 04 2003 - 13:57:00 BST

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