COSMAC Elf Turns 50

The COSMAC Elf, a build-it-yourself computer based on the RCA 1802 CPU, marks its 50th anniversary. A video by Tech Time Traveler traces the machine's origins to a 1976 Popular Electronics article by Joseph Weisbecker, the RCA engineer who designed the 1802 chip. The piece covers the CPU's unusual architecture: 16 general-purpose 16-bit registers, built-in DMA enabling cheap video output, and the lack of a hardware call stack, which required the SCRT (standard call return technique) software convention for subroutine calls. Comments dive into assembly-level detail on how 1802 programmers implemented call/return using register pairs.

Source: https://hackaday.com/2026/09/04/cosmac-elf-turns-50. 8 Sync News only summarizes and links out; content copyright belongs to the authors and original sources.