Posts tagged with “Bill Gates”

The Kill Command

The KILL command was probably the most unusually named command in the TRSDOS disk operating systems for TRS‑80 computers. KILL was used to delete a file, for example: KILL FILENAME/EXT.

The KILL command was supported by versions of TRSDOS for the Model I, Model III, and Model II, as well as the BASIC interpreters for all those machines plus the Model 4, Color Computer, the Model 100, Model 102, Model 200, and the Model 2000.


When the TRS‑80 Model I was introduced on August 3, 1977, it came with Level I BASIC, a 4K BASIC interpreter, in ROM. Level I BASIC was created by Steve Leininger, the designer of the TRS‑80, who based it on the public domain “Palo Alto Tiny BASIC” that Dr. Li-Chen Wang wrote in 1976.

But Radio Shack’s plan was always to upgrade to a more advanced Model I BASIC later. The very first TRS‑80 brochure said that “planned expansion includes an extended Radio Shack Level II BASIC.”


Level III BASIC was an enhanced version of Level II BASIC for the TRS‑80 Model I. It was created by Microsoft, also the authors of Level II BASIC, but sold by GRT Corporation on cassette for $49.95. Level III BASIC was said to be the first consumer product from Microsoft, which had previously sold only to manufacturers.

Rather than sell Level III BASIC directly to consumers, Microsoft decided to release it through GRT Corporation in 1978.