I am nearly ready to try out my JAIR S-100 computer. All that remains is to solder in the terminating resistors on the backplane, and make up a suitable power supply. The trouble is that this baby need a +/-16 and +8 V power, which is a bit unusual. I have lots of options for +/-12, +/-5V etc. I may have to hack something together.
Today, I have populated a SSM OB-1 board I bought recently. It is for setting the start address upon boot up. This board would have been used in an Altair or IMSAI type computer. I will be using it for a S-100 computer that I am building.
There is one crazy bugger on eBay who wants $500 US for one of these. I have a hard time believing it is worth that much.
I picked up this started from a friend last year. It was pretty rusty looking, but it works great. I used to to get my new engine started because it seems to have more torque than the ordinary one I use. Now that the engine is looser, I put the original one back.
Before putting this one away, I decided to clean up the rust and repaint it. I also replaced the mounting plate, as one of the mounting holes was broken. The pictures below show the cleaned up starter.
Received the following S-100 boards from the brother of the person, I bought the lot of boards off of in March. The boards consist of:
The Solid State Music (SSM) OB-1 board is a vector jump and prototyping board that is plug compatible with all S -100 bus mainframes. The board has a full 16 bits of vector jump address and can jump to any individual addressable location. Additional features of the OB -1 include prototyping areas on the board for ten 16 pin integrated circuits, three 24 or 28 pin integrated circuits, plus two spare regulator patterns.
The SSM IO-2 Input/Output, PROM and Universal Board. S-100 bus compatible. Two I/O ports committed, pads provided for three additional ports, including one serial. Other pads to facilitate wiring for a UART, EPROMs etc. Instructions include information on several wiring options. Gold contacts for edge connector. Kit includes parts necessary for two I/O ports.
There are some pretty cool things you can build with this card according to the manual. Also there is a lot of neat projects for it on http://www.glitchwrks.com/s100.htm
After spending the last few evenings re-connecting the engine, I discovered to my dismay that my trusty old 6V battery finally had enough. Hard to believe I had it since 2011. I bought one from Canadian Tire but because the engine is so tight, I was unsuccessful at first in starting it up. After a good recharge, I was finally able to get it to start. I let her run for a good 20 minutes to break it in. After that, I was able to start it easily enough.
Today I put 25 miles on it today, just test driving it. Did a drive by of some of my friends' places who I could not see because of the COVID-19 social distancing protocols in place, and beeped my horn. They appreciated that.
Have to replace the muffler because there is a large piece missing where it joins onto the manifold. This results in some backfiring when coming to a stop. Will fix that tomorrow.
Veronica is on the mend. Today with the help of Mitchell Phillips (one of my son's friends and a general tinkerer like myself), we got the new engine installed. It wasn't easy. It took a bit to get it all lined up so that it slipped into the spline of the transmission, but finally we prevailed.
Now it is just a matter of reinstalling the rest of the components and wiring it up. She should be ready for the road in a few days.
Got this cool vintage electronics kit in the mail today. Philmore used to make crystal radios back in the early days of radio (1920s). My guess is this kit is from the late 1950s or early 1960s.
Yesterday I picked up some S-100 boards and one heavy power supply. Slowly, I will get an S-100 system cobbled together.
Today I have a new toy to play with. All the way from the UK. This is a modern full scale replica of a C64 like the C64Mini (which I got in 2018), however this baby has a working keyboard and also emulates the Vic-20. It also comes with some built in games, , however I can also play any of my own collection off of a USB stick. Pretty cool.
A few days ago I saw a Processor Technology Sol-20 for sale on Kijiji. The seller wanted $1550 Cdn for it and it came with the manual. I decided to bookmark this ad just in case. Last night after discussing the price with a fellow collector, I decided to give an offer. In the end I managed to get the computer for $1150.00 ($865 USD). This is by far the most I have ever paid for a vintage computer (other than when they were new). However, this one was in pristine condition and appeared to be in good enough condition to be functional.
Today I picked it up from the seller, who lived about 50 minutes from my place. Considering the savings in shipping (this baby is quite heavy), I think I definitely got a good deal here.
After I brought it home and inspected it for any obvious issues, I decided to hook it up to my trusty old Commodore 1702 monitor. The Sol-20 uses a SO-239 video connector instead of the more common RCA type. Fortunately I have a good stock of ham radio cables and I was able to find a PL-259 to BNC adapter (PL-259 is the male counterpart to the SO-239), and a BNC to RCA cable. After crossing my fingers, I powered up the computer and it came to life.
No magic smoke appeared. In total I had the computer running for about a half hour. Feeling the air expelled from the fan at the back, I was surprised to feel how cool it was. This is a testament to a well designed Power Supply and spacious case.
The keyboard is a Keytronic capacitive keyboard. Unfortunately, these use a foam and foil type mechanism, which tends to degrade with time. This keyboard is in reasonable shape, however the 'y' and the '8', '9', '0' keys on the main keyboard are not functioning. The space bar also has issues. On the number pad, the '-' key does not work. One thing I have to do is do a foam and foil replacement. This is a tedious job, but I am getting used to it now after doing it on my Hyperion and my Apricot PC.
I have scanned the Sol Systems Manual which includes drawings and other useful information.
Charles Baetsen holds a Bachelor and a Master's degree in Engineering Physics from McMaster University in Hamilton, Canada.