Recreating my experiences using a Comart Quad

Comart Quad

The second business computer – we moved to this from the ICL PC

 

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The specs were:
  • Intel 80186 CPU
  • Running around 10 Mhz
  • 1MB Memory
  • 5 1/4″ 1.2MB Floppy Drive
  • 20/40 MB MFM HARD DISK
  • Concurrent DOS/86 Operating System
  • Four serial ports
  • One parallel port
  • Four Wyse 50 Terminals (serial)
Cost of complete system was around £5K (1986/1987), around £19,500 in 2024 terms
 
Not much material available, there were probably some build changes over the lifetime of the computer so there are some flexibility between reports on the spec.
Comart Quad Magazine advert
So getting to something reasonably close to the setup of back in the day has been an interesting journey and full of false starts and a bit of going through hoops to get there.
 
There isn’t much information online about the Comart Quad but the pieces I have been able to pull together will be included somewhere on this page.  The advert above refers to the Quad running Concurrent DOS, although my memory seems to recall the machine I used running Concurrent CP/M or MPM.  Hopefully this will become clearer as I use the VM more and see what other memories it will jog.
 
Based on the advert being one of the best descriptions I have been able to find online of the actual configuration I’ve replicated this as close as possible for my VM.

We sourced the system from a company based on an advert my boss at the time found in a Sunday newspaper.  It wasn’t brought direct from Comart, but through this company who were re-selling it along with their business accounting software, more on that later.

The VM has finally ended up running in DosBox-X as this was my ideal target as its currently the DOS machine emulator I use the most.

However getting to a working machine that would execute Concurrent DOS with a hard disk image took a while.  I ended up creating the hard disk image using PCem and using this to boot of the floppy IMG images I was able to find for Concurrent DOS 4.1 as the lowest version so far I could get to boot and install.

Once I was able to get PCem to boot of the floppy images with an attached hard disk (IMG) file, it was then fairly easy to use the DSKMAINT program to format the hard disk image. 

The size of the partitions on this version of Concurrent DOS are less than the 20MB hard disk image size, so I ended up creating a DOS and a CP/M image on the disk size available. I don’t have any memories of ever using Concurrent DOS with CP/M formatted disks, but as I have other CP/M machines setup I thought it might be useful later on and I had the free space on the image to use up, so why not.

After PIP copying the files over using the [R] option to make sure the system files copied over the hard disk image was useable under DOSBOX-X using the IMGMOUNT and BOOT options through a config file and seems to be fairly stable.  DOSBOX-X appears to be able to mount the hard disk image without booting the O/S and appears to copy files into it without any issue or complaint so this has helped to get files into the hard disk image without to much extra overhead which has been good news.  It did occur to me later that the Copy command works perfectly well under CDOS, I think I had just gotten into a habit of using PIP recently.

Many thanks to the following links and people involved who made my tinkering around in this particular nostalgic experience even remotely possible: