Any project of this magnitude winds up involving a number of people before it gets completed. I was fortunate to enjoy the support, talents, and skills of the following individuals during design and construction of RC-3:
- Harry Porter – Harry, a computer science professor at Portland State University, graciously allowed us to use his design, supported us via e-mail, and flew out from Oregon to Texas to be with us at the RC-3 dedication ceremony.
- Russ Corley – Russ, then curator at the Goodwill Computer Museum, was tireless in his support for the project, responding to my frequent requests for large format drawing prints, managing somehow to pay for parts out of his meager supply budget, plugging LEDs into panels until his fingers ached, and grinding through my exhaustive tests of the control section, instruction by instruction, clock step by clock step.
- Lon Johnson – Lon came to us via the IBM retirees club, and somehow managed to turn my cryptic design requirements into finished printed-circuit-board designs, providing us with trade standard design files that we could send to our PCB supplier.
- John Mandell – serendipitously, I met John while he was touring the museum. When I mentioned that we were building a relay computer, he asked if we ever needed any machining work done for it. Boy, did we. John was a pleasure to work with. I didn’t have to figure out exactly what I needed and draw it up; I just had to show him the problem and he’d come back a couple days later with an elegant solution and the machined parts to implement it.
- Jon Stanley – We found Jon via an e-mail Harry sent to his fans, informing them of our project. Jon is, in part, responsible for the RC-3 name; he had built his own relay computer based somewhat on Harry’s work, and called it Relay Computer 2. We figured ours was the third one in this lineage, so called ours RC-3. Jon shared the burden of endless soldering with me, wiring several major sections of the machine, including the extremely dense ALU. I only wish my wiring was as neat as his.
- Austin Roche – I co-opted Austin early on to help with the parts selection and logic design for the memory subsystem, and subsequently talked him into doing the wire-wrapped wiring of it.
- Stephen Torrence – Stephen designed a beautiful logo for RC-3 (sneakily embedding my name in ASCII 1’s and 0’s on it), and worked long and hard trying to get our little CNC router to work for front panel construction. When we decided to go with a commercial supplier instead, Stephen translated my dimensioned hole drawings into the CAD/CAM files their system used to make the panels.
- Deanne Row – Deanne, my favorite miracle worker in plexiglass, made the RC-3 side panels and cleverly used mattes to hide unused holes and imperfections in the edges of the reclaimed equipment rack we used.
- Lynn Foster – Lynn came to us via my plea to Single Volunteers of Austin. He wrote the initial configuration tables for the Cross-32 cross assembler, provided valuable input on op-code mnemonic selections, and wrote the assembly source file used for cross assembler validation.
- Orin Winn – Orin wrote the first program that RC-3 executed, a memory test program we used to verify the PROM burning process. He also teased out the internal wiring of the Robot Printer unit, giving me the info I needed to design a driver circuit for it, and constructed the print code translation table.
This project also would not have been a success without our corporate sponsors, whose generous donations are gratefully acknowledged:
- Omron Electronic Components – our major sponsor, Omron donated the relays used to build RC-3.
- Newark Electronics – our primary parts supplier, Newark donated the front panel switches.
- Crenlo/Emcor – builders of the rack we used, they donated the front door assembly.
- Keystone Electronics – donated the insulated standoffs that support the power buses on the relay rails.
- Datasync Engineering – provided us with a copy of their Cross-32 cross assembler, used to program RC-3.
I also want to thank the folks from Single Volunteers of Austin who answered my call for help, even though ultimately we did not use their talents:
- Bill Boulton
- Debbie Brase
- Linda Fugate
- Allen Irby
- Andrea King
- Bobbie Mattord
- Paul Schnizlein
Finally, a tip of the hat to Jeff Diamond, at UT Austin, whose enthusiasm for relay circuits seemed limitless, and whose probing questions made me think about why I was doing things the way I did.