DEC's VT100 firmware, fully disassembled and annotated from 8 KiB of 8080 code
The Annotated VT100 Firmware (2022)
The VT100, launched in 1978, was DEC's first ANSI-compatible terminal and its first to swap discrete logic for a microprocessor, the Intel 8080. This project takes the original 8 KiB firmware and explains how it works, with a fully annotated disassembly linked to the Technical Manual and print set. It also covers why and how the disassembly was made, catalogs bugs and oddities, and introduces Awnty, an 8080 coverage checker.
Slight modifications to the supported escape sequences were made for the cost-reduced follow-on models, the VT101 and VT102, and those changes became the definition of "VT100 compatible," in DEC's internal Video Systems Reference Manual, used for the next 15 years.