Posts tagged with “Microtronix”

The Microtronix Expandable Interface

The Microtronix Expandable Interface was probably the first third-party alternative to the Radio Shack Expansion Interface for the TRS‑80 Model I. It cost $129.95 when it was introduced in late 1978 by Microtronix of Philadelphia, Pennsylvania. According to the product announcement in H&E Computronics, the Expandable Interface was also available in kit form for around $100.00.

The Electric Pencil Lower Case Modification

The best known limitation of the TRS‑80 Model I was its inability to display lower case characters. Although the lower case characters were present in the character set, the Model I lacked the extra memory chip needed to store the bit corresponding to lower case.

The significance of this limitation has been exaggerated over time (it’s worth noting that the contemporary Apple II also lacked lower case), but it created a real problem for word processors.