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brassicGamer
May 31st, 2017, 12:57 AM
Just wanted to share this system with you folks on the off-chance that anyone has some kind of insight into it. Won it on eBay yesterday after apparently being willing to max out a bit higher than the other bidder. I've never seen one before and it appears to be completely undocumented, at least on the 'Web. I have read that BT were looking at testing PC clones (https://books.google.co.uk/books?id=Vy8EAAAAMBAJ&pg=PA18#v=onepage&q&f=false) [Google Books] back in the day, specifically the Compro 88, as they were cheaper than IBM's offering. It's not in my hands yet, so here are some of the seller's pics:

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Observations / assumptions:

- Looks 5150-esque and very well-used.
- Proprietary PSU.
- It's possible BT decided to manufacture their own clone, or re-badge someone else's.
- It's 8-bit and runs off an ISA backplane.
- It has what appears to be a 10base2 card (I don't know what else would use Coax aside from UHF/VHF).
- The short length of the video card would suggest EGA rather than CGA.
- The RAM card appears to have a parallel port on it.
- It has an I/O card including floppy drive controller and serial at the very least (possibly MFM too?)
- It has a CPU card with goodness only knows what processor on it but one would have to guess an AMD / Intel 8088, or NEC as an outside chance.

Apparently it powers on but they've not tested it anymore than that. I have a compatible monitor and I'm hoping it uses the AT keyboard standard rather than XT or I'll need one of those (that'll be another 50). If it is an IBM clone then I can presumably run whatever software I want, install a hard drive controller, sound card, etc. and avoid the cost of finding a 5150/5160. Worst case scenario would be that it's a completely proprietary system and there's no remaining compatible software.

Any other thoughts? I should be picking it up tomorrow.

Malc
June 1st, 2017, 12:22 AM
Looks like a Zenith Data Systems machine, Z-150 (https://archive.org/details/ZenithDataSystemsZ-150PcSalesFlyer) ??, I know BT used ZDS machines back in the day, I have a Z-248 badged " British Telecom " and a Zenith CGA monitor Badged " BT ". Give it a good clean up and post some pics :-)

g4ugm
June 1st, 2017, 07:56 AM
I agree, it looks very much like a re-badged Heath/zenith machine. There should be an FCC ID (I know its a UK machine but I bet it has one) on the CPU board. You can then look it up in the FCC database and check.

The card with the coax connector looks like a "Cheapernet" card but its possible its an IBM 3270 terminal card. BT were big users of IBM Mainframes (and may still have some) which used 3270 terminals connected over co-ax. They also had software that allowed DOS to use Mainframe disks as network drives...

eswan
June 1st, 2017, 10:08 AM
My bet on the coax card is arcnet. That dip switch on the top edge looks familiar. If I remember correctly, you had to set a unique station id with it, similar to ethernet's mac address.

brassicGamer
June 2nd, 2017, 03:30 AM
Cheers guys. Looks like it's a variation on the Z-150, as it doesn't have CGA built in to the I/O card. Found an extensive review online: https://archive.org/stream/byte-magazine-1984-12/1984_12_BYTE_09-13_Communications#page/n251/mode/2up

A-ko
June 3rd, 2017, 08:24 AM
Case and interior layout looks identical to my Zenith Z-158. Without a doubt a Heath/Zenith clone.

JohnElliott
June 3rd, 2017, 09:50 AM
I've got a BT-badged Zenith keyboard. It speaks XT protocol, so I expect your system will need an XT keyboard.

brassicGamer
June 6th, 2017, 12:57 AM
My bet on the coax card is arcnet. That dip switch on the top edge looks familiar. If I remember correctly, you had to set a unique station id with it, similar to ethernet's mac address.

Spot-on. Novell-branded ARCNet card from 1987. Hadn't heard of the standard before but it seems that, in that year at least, it shared a similar market share to Ethernet's. That is until the latter moved to twisted pair and took over. I wonder why BT went with ARCNet - can't find any reference to it in the general IT press, but I imagine it would have been publicised in one of their internal newsletters at the time.

38968


Case and interior layout looks identical to my Zenith Z-158. Without a doubt a Heath/Zenith clone.

I think it's a Z-159, the last XT-class model they made. Based on this article (https://books.google.co.uk/books?id=BDwEAAAAMBAJ&pg=PA17#v=onepage&q&f=false) [InfoWorld] it seems I have a Model 12 (2x floppy drives plus EGA). I've dismantled it and will perform a full physical inspection prior to any attempts to power it on. While the cards all look good and the jumpers all seem to be set correctly (http://arvutimuuseum.ee/th99/m/U-Z/34129.htm) [arvutimuuseum], the backplane could do with a cleanup and the case may be retr0bright-able if it's not too brittle. Whether the floppy drives work is pot luck, but I can try them in another machine. I'll strip down and clean up the PSU - the scrapper I got this from said that it 'powered on' but I want to be super careful - it's proprietary so I'm not optimistic about a 2nd chance on this system.

I have a CGA card for it (not IBM, unfortunately), am not immediately bothered about fixed storage, and may be able to acquire an XT-compatible keyboard through Amibay. Here are my pics of the cards (https://drive.google.com/drive/folders/0B7vVWBbEOcWjQWptcEtObzNvMzA?usp=sharing) [Google Drive]. No FCC ID apparent and it's a shame there's no co-pro.

brassicGamer
June 19th, 2017, 01:25 AM
Looks like a Zenith Data Systems machine, Z-150 (https://archive.org/details/ZenithDataSystemsZ-150PcSalesFlyer) ??, I know BT used ZDS machines back in the day, I have a Z-248 badged " British Telecom " and a Zenith CGA monitor Badged " BT ". Give it a good clean up and post some pics :-)

Malc, do you have a blog entry or video / photos of this system? I don't think there are many remaining BT systems out there.

Malc
June 19th, 2017, 02:10 AM
No, I tried building a website to document my collection several times but after about 5 minutes i started loosing the will to live so gave up on that. I no longer have the collection i once had, Got rid of 90% of it, Just keep what i actually have a use for and enjoy using now, My Z-248 is resting got to get a new battery for it one day.