Version 2.1: Add Model 4P support

This version adds initial support for the TRS-80 Model 4P. (The same ROM is likely to work on the Model 4 and 4D, but is untested on those machines).

Additionally, there is preliminary support for booting to floppy or hard drive on the Model II after running diagnostics, but booting the Model II family is not yet reliable.

Version 2.0: Includes Model II support

This release includes a diagnostic ROM for the TRS-80 Model II.

Version 1.5: requires no working RAM

This is a rewrite of the initial release to free the ROM from dependency on working RAM. It also prepares the code base for working on other machines, such as the Model 2, Model 4, and other classic Z80 systems.

TRS-80 Model 1 and 3 Diagnostic ROM Version 1.0

Initial release for the public. Version 1.0.