Sometime in 2011, Cameron Cooper planted the idea of reproducing a SCELBI computer into my head. Once he had me convinced, I knew that I wanted to reproduce the entire line of SCELBI computers and I/O peripherals. SCELBI produced 16 different PCBs over the short lived life of their computer line, so this was going to be no small task. I knew that it would take a long time, and I was never sure that I would be able to maintain focus long enough to do them all.

At last, after 5 years, the last reproduction SCELBI PCBs have been made! Though I still have to build them up, write some software, and test them, the hard and most expensive part of making the PCBs has been done.

The digital board is the big one and the analog board is the small one. The digital board takes 16 bits of input from the computer for each character and coverts it into 4 bit digital X and Y vectors and the blanking information that make up a single character. The analog board coverts the XY vectors into analog voltages suitable for oscilloscope input. The analog card also will control horizontal and vertical positioning of each succeeding character and line.

I still have some parts to acquire, but I should have the missing parts and be able to begin assembly in about a week or two. Meanwhile, I can do some work on the software.

Here is the list of all 16 SCELBI PCBs
Main System Cards
1100 CPU – 8H/8B
1101 Data bus buffer – 8H/8B
1102 Input – 8H/8B
1103 Backplane – 8H
1104 Front Panel – 8H/8B
1105 1K SRAM – 8H
1106 Memory Expansion – 8B
1107 4K SRAM – 8B
1108 Backplane – 8B
1109 PROM – 8B

Peripheral Cards
2100 Oscilloscope digital
2101 Oscilloscope analog
2102 Audio Tape output
2103 Audio Tape read
2104 Teletype interface
2105 Keyboard