View Full Version : Sol-PC acquisition

July 15th, 2017, 02:15 PM
I had mentioned this acquisition in falter's Sol Prototype Project (http://www.vcfed.org/forum/showthread.php?55931-The-Sol-Prototype-Project) thread but thought this could use a dedicated post so as not to clog up his original post. Most of this thread is similar to my original post but I have pics posted now.

I have recently acquired a home-made Sol-PC with documentation from October 1976. The original owner appears to have been a Sol-PCB purchaser (paid $40). The Sol-PC Rev D board looks like the regular ďS-100 slot in the middleĒ board that is hand soldered, has a third-party ASCII keyboard from Electronics Warehouse (EW-100), a hand built power supply and comes in a case that looks nothing like a SOL-20 (clearly a third-party case as shown below).

The Sol-PCB may have been purchased from the original Popular Electronics article from July 1976. I donít see any evidence of the Sol-PCB being sold in any subsequent price lists or this September 1976 press release (http://sol20.org/articles/img/Sol_20_board_press_release.pdf) but it is mentioned in the PE article so I believe this may have been from that original article.

The documentation I have is quite sparse yet I believe it is complete. The cover letter is visible below. As noted in the letter, it comes with full schematics, a placement guide and other information for the builder. The components are all over the place in terms of dates so I donít think this was a pre-packaged kit. The personality module is also a bit strange because itís a 2708 version from 1977 (I think this was a replacement). The actual Intel 2708 is missing in one or two photos because, sadly, it is blank and I canít seem to erase what is left on it. It would have contained CONSOL since it is a 1k x 8 chip.

The Rev D schematics are dated September 23, 1976 so itís not too far off of the article date. Full size and more pics are at my site posted here (http://vintagecomputer.ca/processor-technology-sol-pc-an-early-sol-20-minus-the-20/). Iíll scan the rest of the documentation and post soon.


July 15th, 2017, 08:17 PM
Cool to get a SOL computer and I really like that case almost as much as a real SOL case never seen a case like that one before.


July 16th, 2017, 06:49 AM
Sweet museum piece!

July 17th, 2017, 03:14 AM
Thanks. I do love the "homebrew" aspect of this. It's a good example of the times. Incidentally, this came with an Ithaca Intersystems DPS-1 so I believe this was the terminal for it.

I have scanned and posted my documentation if anyone is interested. You can go to http://vintagecomputer.ca/files-area/ and look in the Sol-PC folder.

July 21st, 2017, 12:33 PM
Is your DPS-1 the blinkin light version? :inlove:

July 21st, 2017, 02:12 PM
Is your DPS-1 the blinkin light version? :inlove:

Yes but sadly, it's missing some of it's signature orange paddles for the front switches. I am also missing the Run/Stop switch. Of note is the serial number. The previous owner was clearly an early adopter for both this DPS-1 and the Sol-PC! Here are some more pics of the Ithaca InterSystems DPS-1: http://vintagecomputer.ca/ithaca-intersystems-dps-1/

Note: What looks like damage to the front panel is actually the protective wrap still intact. It's in great shape except for those paddles missing.


July 22nd, 2017, 10:12 AM
Gotta love them early adopters! Never did check the s/n on mine.

In this age of 3D printing, you could clone a batch of those paddles easily. The only trick might be matching the surface texture. (if you are a perfectionist)

July 22nd, 2017, 10:16 AM
Do you know the part number of the correct (original) C&K RUN/STOP switch? They might still be available.
Sorry, but my curiosity is killin my cat (LOL) - do you have the original barrel key for it?

July 22nd, 2017, 10:50 AM
Do you know the part number of the correct (original) C&K RUN/STOP switch? They might still be available.

According to Herb Johnson's page here: http://www.retrotechnology.com/restore/res_ithaca.html the Run/Stop switch is a C&K 7205J3V6BE2 DPDT switch. I wonder if something like this could be modified to work: http://www.ebay.ca/itm/191871770627 I thought I'd keep looking for now and see if I can find something closer.

Sorry, but my curiosity is killin my cat (LOL) - do you have the original barrel key for it?

No original key, unfortunately. I do have a spare barrel switch with key that I will try at some point. I just have to find it :)

July 25th, 2017, 11:07 AM
Wow, I finally got a chance to download and look at the SolPC documentation. Very scary.... No support from PT according to the docs to get the system running. It was sold as a PCB only for $40 no chips or sockets.

What I find interesting is that this also confirms something I suspected, which was the Rev-D board is really the first one available to the public. I have a RevD and Rev-E Sol-20.