COSMAC Elf

The COSMAC Elf is an early single-board personal computer based on the RCA 1802 microprocessor. It was originally described in a series of construction articles in Popular Electronics magazine in 1976 and 1977. The system operated without read-only memory (ROM) chips—programs were entered directly into RAM memory using the 1802's integrated direct memory access (DMA), 8 toggle switches, and an Input push button. An updated commercial version called the COSMAC VIP was later sold in kit form.