Posts in the “Operating Systems” Category - page 2
The Model I TRSDOS command shell supported a number of internal commands, as documented by the TRSDOS 2.3 Reference Manual. Most of the commands were also supported by other TRS‑80 operating systems, although they usually added extra features beyond the TRSDOS versions.
TRSDOS, referred to as DOS in some early references, was Radio Shack’s official disk operating system for the Model I. The name stood for Tandy Radio Shack Disk Operating System. It was bundled with Radio Shack’s floppy disk upgrade, but it could also be purchased separately.