MCI & Harrison

by Ray A. Rayburn
(Colorado, USA)

David Harrison developed the world's first "in-line" console where the output channel was located above the input channel. This was also the first console where the circuitry for the entire input channel and the entire output channel were both on a single printed circuit board (PCB). By using these huge PCBs it greatly reduced the cost to manufacture the console. Cost was further reduced by plugging the input/output PCBs into a large back-plane PCB which largely eliminated the hand wiring in the console.


By the time this console design was finished Dave did not have the funds to put it into production, so he licensed the design to MCI who called it the MCI400.

After a bit MCI asked David for a next generation console design, but also secretly designed a next generation console in-house. When Harrison delivered his new design to MCI he discovered they were releasing their own design as the MCI500.

With a finished console design, and very little money, David Harrison started Harrison, with that console as the first product.

Ray A. Rayburn

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