Posts tagged with “Larry Holmes”

The Holmes VID-80

The Holmes VID-80 was a popular add-on for the TRS‑80 Model I and III. Introduced by Holmes Engineering, Inc. in 1982, the VID-80 offered two related features:

It expanded the TRS‑80 screen from 64 characters wide by 16 characters high to the larger 80 characters wide by 24 characters wide.
It changed the TRS‑80 memory map to allow running the CP/M operating system.

The Holmes Internal Memory

Although the TRS‑80 Model I supported up to 48K of memory, there were only sockets for 16K within the Model I itself. The only official way to add more memory was to buy the Radio Shack Expansion Interface, which had sockets for an additional 32K of memory, for 48K in total. The Expansion Interface (without any memory) cost $299, making any kind of official memory expansion very expensive.

The other important feature of the Expansion Interface was the built-in floppy disk controller.