Compusense, DragonPlus and the hard disk interface ...

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tjewell
Posts: 346
Joined: Mon Oct 19, 2009 4:58 pm
Location: Cambridge, England

Compusense, DragonPlus and the hard disk interface ...

Post by tjewell »

Hi all,

I've been chatting to Ted Oprychal, former MD of Compusense. Among other things, I asked the two questions you probably all want to know -

What became of the hard disk interface you advertised in Dragon User in 1986, and demonstrated at the 6809 show?

"The hard disk drive, prototype, was a SASI controller which worked remarkably well as a SS30 card on the SWTPC or Dragon system. We owned some hard disks – 5mb and 10MB capacity – which were available for around £500.00. They were excellent for Flex and OS9 but the estimated number of sales was so low that we decided not to go ahead. I do remember some sceptical faces at the shows but these were real enough and were used in-house to eliminate old 8” floppy drives. At the time, a Winchester drive cost several thousand pounds. The interface was pretty simple, a couple of bi-directional buffers. The driver code was written for Flex – no I don’t have a copy – it was fairly straightforward."

"The Hard drive: It was one of the first to have a 5 ¼ inch drive footprint and required similar power levels. The on-board controller was integrated with the drive. All that was required was a bidirectional interface with software handling. Nothing fancy, however that was appropriate for a Dragon. The drives were extremely reliable"

Do you still have anything from that time? Software? Prototypes?

"We owned hundreds of 8” volumes. These were packed into tea chests when we moved out of our building and succumbed to water damage. I believe I said “oh dear” or something like that when I found out. It was probably all for the best. We disposed of stuff by the skip load. [...] I threw out a lot of stuff and EBay got my old 6809 system"

As for Compusense itself, after the Dragon faded away, they moved into 6809 and 68000 co-processor cards for PCs. When that market also faded away, Compusense ceased being active in retail and was a vehicle for Ted's consultancy work. I think Ted is now retired and produces designs for 3D kits for model railways. I'm hoping he'll come along to the Meetup in June!

Tony
RoyCoates
Posts: 14
Joined: Fri Apr 08, 2011 2:43 pm

Re: Compusense, DragonPlus and the hard disk interface ...

Post by RoyCoates »

Tony,
I am amazed that there is still so much interest in the Dragon after all these years and was tickled pink to find mention of Flex - an operating system I absolutely loved working with.

I have extremely fond memories of Ted and did some work for him 'back in the day' mostly I think on the Flex Utilities package.

I do have a stash of Dragon gear in the attic which I did promise someone I'd have a rummage through some years ago but other things got in the way of that. I believe that I still have my Dragon Plus system up there along with a stack of floppy disks from the period - I wonder if they are still usable though?

Drop me a line and I'll see what I can conjure up.

Cheers,

Roy.
tjewell
Posts: 346
Joined: Mon Oct 19, 2009 4:58 pm
Location: Cambridge, England

Re: Compusense, DragonPlus and the hard disk interface ...

Post by tjewell »

Hi Roy - dropped you a PM, but it's stuck in the Outbox! You can drop me an email on tonyjewell AT gmail ...
RoyCoates
Posts: 14
Joined: Fri Apr 08, 2011 2:43 pm

Re: Compusense, DragonPlus and the hard disk interface ...

Post by RoyCoates »

Got it, Tony - and have replied.

Catch you now via email.

Cheers,

Roy.
prime
Posts: 266
Joined: Fri Apr 10, 2009 1:40 am

Re: Compusense, DragonPlus and the hard disk interface ...

Post by prime »

Is that the Roy Cotes of Dragonuser and Manic Miner / Jet Set Willy fame?

Cheers.

Phill.
RoyCoates
Posts: 14
Joined: Fri Apr 08, 2011 2:43 pm

Re: Compusense, DragonPlus and the hard disk interface ...

Post by RoyCoates »

Yes, I get the blame for a lot of other things too! :D
tjewell
Posts: 346
Joined: Mon Oct 19, 2009 4:58 pm
Location: Cambridge, England

Re: Compusense, DragonPlus and the hard disk interface ...

Post by tjewell »

Roy, you must come to the meetup in June!

Found a little more on the hard drive ... Ted says

"We hooked up with a tiny company/individual that advertised in 68’ Micro Journal. They were offering a Sasi controller + drivers for st506 drives. Basically a homemade card. It worked, good software. The card was re-engineered by us, I made up a sample batch of boards. As I wrote before, it was basically some buffers. I imagine that it could have been done with a parallel port if one was determined. The simple hardware brought the costings down out of the red zone, but not enough to make it worthwhile for us to proceed.
[...]
I’ve been looking at the 68’ Journal and I think it was a person/company called “Wellwritten Enterprises”, see image. Many of the individuals producing hardware and software for the 68xx processors were superb engineers, often trained by the military. It was policy to evaluate every interesting product that was advertised in the 68’ Journal and evaluate it. I would call the company and buy a sample. It was an effective way to introduce ourselves too.

If the hard disk had gone to production then the software would have been on a banked eprom on the board. The driver code took up a lot of space, almost 8k :)"
ss-50 hard disk.png
ss-50 hard disk.png (105.63 KiB) Viewed 5010 times
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