I purchased my Sol-20 from a chemical company in 1980. They were having trouble with it and upgraded to an Apple setup. The computer would work but after a while it would fail. I found out that it was a heat problem. They had 4 memory boards in it and they were producing heat to beat the band. After designing a single board 48K memory board, these 4 boards could be removed and the machine worked great again. It has a Sanyo monitor and 3, 5 1/4 inch hard sector disk drives. There is also a serial board to drive a ASR 33 teletype. I have a few programs, BASIC and mail merge, plus a few others I do not remember. As time wore on, the keyboard started to fail, one key at a time. Now it is not usable. Hopefully this winter I want to try and replace the foam disk and insulators and maybe this machine will come back to life. Anyway, it's a neat little machine and I had a lot of fun with it, maybe again.

I had a SOL-20. I was a Ph.D. taking a hiatus from academe due to my wife's job starting in 1983. My father bought it for me as a Ph.D. completion present from a techie he knew. I used it to write and publish four research articles, which gave me the opportunity to return to get a professorial job in 1987 that I maintained for 31 years before retiring, plus the beginning of what became my first book I bought it from a techie who jury-rigged connections to two 5 1/4 floppy disk reader/writers. I also had a card that gave be CP/M which in turn allowed me to write some simple statistical programs in BASIC that were incredibly helpful. I had WordPerfect 2 which took up 56k of the 64k available RAM. Unfortunately the techie mailed it to me, and in so doing some of the extra cards became dislodged and scratched the motherboard. As a consequence, the computer eventually became dysfunctional and I ended up replacing it with an Apple 2.
Years later my wife and I were at the Smithsonian Museum of American History, and they had an excellent multi-room exhibit of the history of computers, starting with looms that worked by what were equivalent to data cards. We got to a room with early microcomputers. Most were on a table and labeled; Altair, Commodore, Apple 1, etc. Under one of the tables, on the floor, unmarked, was a Sol. I was thrilled to see it again. I'm sorry that it became dysfunctional, because if it hadn't I'd still have it to play with.
Charlie Pavitt, chazzq@udel.edu

Glad I found this. The Sol-20 is what fired up a 36-year career in the computer industry. I still have the entire original working setup - including the cassette recorder I used back in 1977 for I/O (I don’t have the original AM/FM radio I used for sound effects - you know, phasers and stuff with for-next loops - but I can probably find one!). I fired the system up about a decade ago, and we recently moved, so I plan to do it again soon. I have all of the original manuals and a lot of software - so as I “poke” around, if I find something that isn’t here, I’ll post it. Here’s hoping my cassettes haven’t degraded.

I have a SOL-20 which I Purchased January 1, 1978 in CA (working on remembering the computer store, in the LA Area.).
Since I celebrated my 80th this year, it is time to reduce my technical hording. Today, I started on cleaning up and restoring the SOL back to Original, however after finding your Site and reading a bit, it may be that not restoring or at least providing the Mod Parts to a new owner would be best.
The SOL was used from day one by two Engineers one S/W and one H/W. Modified with a front Panel Display (Hex) and Address Switches. Bus expansion and a big 5V Supply also.
I have Photo/Video-Documented what I have as well as what I am doing. In the interest of finding a buyer I would be pleased to share that information with you and your associates should you be interested.
Best Regards,
Ben Bibb, EE, NCE
Cedar Park, TX
512.219.7374

I still have the Sol-20 I bought back in 1979, I think. Someone else assembled the main board, I bought that from him and bought the rest of the kit and assembled it. It is in my closet, I'm sure it no longer operates, it's had a rough storage life.

I would like very much to find another keyboard, a modern USB one, that feels similar to the Sol-20 keyboard. Most of the ones I've encountered are loud and feel rough and sound echo-y.

Thank you for keeping all this alive! Can we port the simulator to Linux? Windows.... just isn't the right spirit!

I still have some punched tape off of a TTY33 that was connected to 4 SOLs, in a youth club in Jerusalem, 1979/...

I was just a baby when these things came aroud, so I never tinkered with any of these computers, and I've never seen a Sol. I never even heard about the Sol-20 until some time ago when I started digging into the history of one of my hobbies, which is computer chess. I am trying to emulate some of the old systems, inlcuding mainframe-stuff from the 60s and 70s. Some of those things are a pain to get working and operate. But then I came across 8080 Chess for Sol-20. It was significant because it was the first micro computer chess program entered into competitions with chess programs running on larger computers, in the 8th North American Computer Chess championship. It even scored a point, although the way this happened was rather embarassing for anybody involved: In the first round, 8080 Chess was completely outplayed by it's opponent, Ostrich running on a custom multi-processor beast. But right before Ostrich was about to deliver the fatal blow, the program locked up due to a bug, and 8080 Chess was awarded the full point.

Digging around for the program and emulator I found this site, which contained both an easy to use emulator, the full program _and_ full documentation! I wish all of these programs were this easy to get up and running today! I've played quite a bit with this program. Chess-wise, it is quite weak, probably on par with the more commonly known Sargon which came out the next year. The interface also has some quirks, such as the cumbersome control character commands used for special moves and operations such as castling, and square names not being rotated when you swap sides. But the documentation is a pleasant surprise; It is very thorough, and even quite entertaining in places.

So, a big thank you for maintaining this site, keeping the Sol-20 legacy alive and introducing it to generations that knew nothing about these computers when they were around!

Hello Everyone:

I remembering playing Targ on the Sol-20 that my Dad bought. I just found The Sol-20, cassettes, and users manual. Not sure if it works and don't have the power supply cord. What kind do I need and where could I find one. I have a monitor, cords, and cassette player. It is in Colorado. If anybody is interested in buying, let me know. Thanks.

I built my first SOL-20 in 1976, and thus began my career in related computer industry. I still have the original with many upgrades! My thanks to the early pioneers for bringing at great product to us hobbyists.

Rick

My Grandfather had built one of the Sol-20 from the kit. The computer has been sitting in my grandmother's garage since the day they upgraded from it. I finally decided to take it down and start working with it. Haven't quite figured it out yet, but Ill get there.

Thank you for the awesome resources!

I needed the manual for the 8K Static Ram board (version with the switches at the top right corner) and found it in your "Manuals" download section. Thanks. Nice looking website; I've stored its URL in my Vintage Systems links.

I had two Sol 20 computers, just sold one of them. I still have lots of other old equipment.

Justin.

I have 2 of the Sol 20's and SW and manuals... what are you still looking for?

I guess I should mention that I am selling off the rest of the vintage S-100 and Apple stuff I have to get the seed money I need to build-up a couple hundred RoboGuts™ Kits so I can start teaching classes at the local Boys & Girls clubs, Scouts, YMCA etc...

http://www.brainless.org/MultiMedia/Documents/Computer/DocumentBin/

No I do not want to break up this bundle.

Hi,

Long time since I (sadly) sold the Sol-20 I built from a kit. My first computer was a MITS Altair 8800, then I got a Motorola MEK6800D1 (still have it), then after selling the Altair I had money to build the Sol-20 and like a fool sold it to get an Apple II. I had lots of fun with the Apple but wish I had kept the Altair and Sol-20.

Anyway now I've been developing beginner robotics S.T.E.A.M. program for young children 5+ ... and any other beginners.

Great site! Thanks Mr Battle! I found this web-site a few years ago when I was restoring my Sol-20. I come back from time to time and always enjoy the new information that is periodically added. I bought a Sol-20 a few years ago and set it up every now and then to relive the early days of computing with my sons and grandsons. They like to hear the stories of how computers and computer gaming have evolved over the years. They get a kick out of playing Target. The latest Sol project I have in mind is to make a reproduction Sol-20 manual. Anyone ever make their own manual?

Apparently Steve Jobs used Sol 20 ideas when creating the Apple I and Apple II computers.

Everyone needs to look high and low to find ALL the stuff for this computer so it can be integrated into this website: [1] Contents of Proteus software collections #4, #5, #6, #9, #10 [2] source code to Processor Tech software [3] Your files, programs, disks, tapes, WAV files of tapes [4] Original documents and manuals [5] More personality module ROMs

The SOL-20 appears to be a much more frendlier alternative to the Altair, IMSAI, and other S-100 computers.
And this site presents computer scientists with a wonderful Solace emulator with complete source code to improve and explore.

It would be great to see some new programs, games and modules created.
And I would like to see all the 8080 stuff ported to this emulator.

Fantastic resource. Thanks for maintaining it. In 1981-82 we had a Sol 20 with HELIOS II disk drive in the then-embryonic computer room in Semiahmoo High School, White Rock, B.C., Canada, which was used to introduce students to computers and programming in BASIC until we got the first 8K Commodore PET later. It sparked my interest in computers as a 17 yr old which has continued (rabidly) until this very day.

Our HELIOS II drive was *notoriously* unreliable, and the support tech was coming in weekly to fix the thing. The school used it for a few support programs (including a Library book inventory/ control program written by yours truly), and when the school got rid of it, I inherited all the manuals for everything which unfortunately were later lost in a storage incident.

I hope to acquire a system soon with the HELIOS II and put it back in commission - if only so I can remember all the swear words I threw at the thing in Grade 11

chancewolf@me.com

THERE IT IS! I could never remember what that PC was that my dad bought when I was a kid. I started my programming on this old boy. Thanks for making this site. I am going to start looking for one of these right now.

Thanks for maintaining this site. I have visited quite often and do have one Sol-20 I am still in the process of restoring. I also have a working Sol-20/Helios II system that works beautifully after replacing some capacitors to restore the drive. Pictures I took some time back are here if you're interested. http://vintagecomputer.ca/?computers=processor-technology-helios-ii I am not an original owner/builder but am fascinated by computers of this era. Thanks again.