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ASCI u68 System X - power cord?

falter

falter

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Joined
Jan 22, 2011
Messages
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Location
Vancouver, BC
Hi there,

Among my collection i have an ASCI u68 System X. It did not come with a power cord and I have no idea if it works. The cord socket is a bit weird.. three prongs, but not really in any configuration I've ever seen. I was wondering if anyone was familiar with these machines and if there was a 'generic' power cord out there that might work? I'd love to see it fire up.
 
Perhaps three round pins in a lozenge-shaped recess, with the third (middle) pin slightly offset downwards? You used to see these on a lot of old office equipment and also on old HP gear.

If this is it, I think I still have some notes on where to get power cords.
 
Does it look like this? I found this discussed on http://www.sphere.bc.ca/test/hp1.html, but it sounds like they're out.

hp-cord2.jpg
 
If it is the part pictured above, you need to be careful. There were two "standard" configurations, differing only in which side was the "hot" side of the line. On some equipment it matters.

Volex used to have both styles in their catalog; I don't know if they still do.
 
Chuck(G) said:
If it is the part pictured above, you need to be careful. There were two "standard" configurations, differing only in which side was the "hot" side of the line. On some equipment it matters.

Volex used to have both styles in their catalog; I don't know if they still do.
Click to expand...

Wow thanks!! Yeah that looks right. I've not had much luck finding detailed info on this unit so I've been reluctant to just buy a cord anywhere. It seems to be a mostly 'off the shelf' kind of thing so hopefully they would have used a standard calculator cord.
 
Sorry to dredge this thread up.. but I am finally getting around to getting the power cord I need to see if this ASCI thing works. I understand there can be a difference in terms of which side of the line is 'hot' as the standard for that power cord was not quite nailed down. How would I go about determining which side is which on my System X to be sure?
 
20140202_132922.jpg 20140202_132903.jpg

I got the power cover off.. so I can see the wires now. IIRC black is 'hot'. So I guess the next question is, how do I ensure the power cord I buy is wired that way? :)

Also I discovered something else also pictured.. a chip with 'BAD' etched in it. Dang. I hope this is going to work.

Also if anyone ever hears of a line on the BASIC add on board you could get for these machines, I would be interested. I've never seen one offered anywhere but I'd be all over it if there was.
 
The fuse is always in the "hot" side of the line. To see if your cord is the right one, plug it into the power socket on the rear of your unit, then use a continuity tester to see which prong is the "hot" one. Facing the wall plug with the ground prong on the bottom, the hot conductor is the left one--that is, the blade that goes into the slightly smaller slot in the AC wall receptacle.

The IC marked bad is a common MC6821 PIA--you can still find them around. (the "S" siffix signifies a CerDIP package, nothing more).
 
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Chuck(G) said:
The fuse is always in the "hot" side of the line. To see if your cord is the right one, plug it into the power socket on the rear of your unit, then use a continuity tester to see which prong is the "hot" one. Facing the wall plug with the ground prong on the bottom, the hot conductor is the left one--that is, the blade that goes into the slightly smaller slot in the AC wall receptacle.

The IC marked bad is a common MC6821 PIA--you can still find them around. (the "S" siffix signifies a CerDIP package, nothing more).
Click to expand...

Thanks Chuck.. one thing I'm curious about -- I didn't see any kind of transformer in there. Does that seem right to you? I'm wondering if there's any possibility there was some kind of 'brick' adapter that belonged with this thing.
 
That's hard to say, without a good view of the innards. It could be that there is a small switching supply in this thing, but that's just a guess. Where do the wires go after the power socket? Could be that someone did some scavenging...
 
Found it. It's under the faceplate with all the commands/computer name written on it. Big thing. This machine is really in very clean condition.. no rust, all wires in great shape. If I can just nail down the power cord situation, I'm happening.
 
I believe that I indicated which is which. Plug the cord into the unit and see which AC plug blade connects to the black wire. That should correspond to the narrower opening in an AC wall outlet.

7_outlet_wiring.jpg


If the conductors appear to be reversed for your Volex cord, just resolder them at the power receptacle in the unit. Easy peasy.
 
Thanks for your guide, Chuck. The power cord arrived today, and as it turned out, I had to change poles internally. It fires up. I think it's slightly off.. but of course I also don't know hex and haven't a clue how to operate this thing, lacking a manual. Couple times it was like it didn't want to start up. But as I use it more its getting more consistent.

20140213_165634.jpg
20140213_165606.jpg

If anyone ever sees or hears of a manual somewhere, preferably online, please let me know. I'd love to try operating it and seeing what it can/can't do.
 
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FYI. I have recently obtained an ASCI u68 system, and after a significant amount of reverse engineering work, I have developed a utility ROM for it, as well as providing some useful information here (including my own document, a copy of the monitor ROM image, and even a disassembly of the monitor ROM):

https://drive.google.com/drive/folde...s4?usp=sharing

This forms part of my free archive for single board computer systems, available here:

https://drive.google.com/drive/folde...989yOOjjNMUcUR

There is some info on a paid archive, which contains software I have developed myself, including the utility ROM for the ASCI u68 board.
 
Well done! Wow it's been 7 years I guess since I last messed about with that machine. I keep hoping to come across the expansion board that has the BASIC ROMs on it. But they never appear loose.
 
What a great looking trainer! That looks an EXORbus slot (43 pins / row?), so you have a lot of expansion options. If you can find an image of the BASIC ROM, it wouldn't be too hard to get it running on some alternative card.
 
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