Re: PET CP/M Revisited

From: Mike Naberezny <>
Date: Mon, 22 Jul 2013 23:22:08 -0700
Message-ID: <>
Hi Ruud,

On 7/22/13 10:35 PM, Baltissen, GJPAA (Ruud) wrote:
> When Patryk and I visited Anders some years ago, we got several boxes that
> looked like the second one. I don't know if Patryk wanted some as well
> otherwise they ended up all with me. I still have them and I'll check
> things this evening.

Anders was nice enough to send one of his boxes to me.  The one that he sent 
me is a HardBox.  The HardBox and the SoftBox are the same hardware with 
different EPROMs and minor configuration differences.

The HardBox provides a CBM DOS interface to a Corvus hard drive.  The SoftBox 
is a CP/M computer.  It can optionally use a Corvus under CP/M but the Corvus 
can't be used as a CBM DOS device.

I compared the HardBox and SoftBox boards and worked out the differences.  I 
was able to successfully convert a HardBox into a SoftBox and run CP/M on it. 
  Steve Gray has done it now also.

> I never was able to do anything with them because I couldn't find any info
> on the internet.

I have both types working now and can help.  Anders scanned the HardBox manual 
and made a disk image with the utilities.  Those are on my site now.  I was 
able to format a Corvus drive on the HardBox using the disk.

Almost all of my work has been on the SoftBox.  I got the disk and manual from 
former employees of Small Systems Engineering.  I had the disk for many months 
before the manual was found.  During that time, I disassembled the Z80 BIOS 
and most of the utilities to find out how they work.  I now have a good 
understanding of the SoftBox internals.

I have posted dumps of the EPROMs that I have.  Please check if you have a 
different version, especially if it is a SoftBox.


Mike Naberezny (

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Received on 2013-07-23 07:00:16

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