The Norcom TC-III

written by Matthew Reed

Norcom TC-III advertisement

NTC advertisement from the December 1983 issue of 80 Micro

The TRS-80 Model III added some nice improvements to the Model I and boasted nearly complete compatibility. But there were still some areas of incompatibility. Considering that most TRS-80 software development moved to the Model III, it was understandable that many Model I owners felt left behind.

The Norcom TC-III was a $399.00 ($499.00 factory installed) motherboard replacement for the Model I that promised all Model III features right in the Model I case. It was sold by Northern Information Technology Corp. The advertisements touted the following features:

  • Uses Model I keyboard, case, monitor and power supply
  • Includes full 48K memory, disk controller, printer and external I/O ports same as Model III
  • All Model III features plus reverse video and output to drive external speaker with no additional hardware
  • Uses Model III BASIC ROMs or other EPROMs
  • Runs Model III software
  • No Expansion Interface needed – it’s all built in
  • RS-232 add-in accessory board available

Although not explicitly stated by the advertisements, it appears that the TC-III was able to use a Model I owner’s existing external floppy drives. That means that a TC-III upgrade would have amounted to a substantial cost savings over buying a Model III with floppy drives. A motherboard upgrade is a common idea today, but it was pretty novel at the time.

Categories: Hardware


Al Hartman says:

The “TC” in TC-III stood for “Trash Compactor.”

I wanted one of these, and I’m sorry that I never got one.