 The Altair 8800 was modeled after early 1970s minicomputers such as the Data General Nova. These machines contained a CPU board, memory boards, and I / O boards; the data storage and display terminal were external devices. The Teletype Model 33 ASR was a popular terminal because it provided printed output and data storage on punched paper tape. More advanced systems would have 8-inch floppy disks and a video terminal that would display 24 lines of 80 characters such as the ADM-3A. (No graphics were available and lower-case letters were a $ 75 option.) Most of these computers had a front panel with toggle switches for entering data and lights for displaying it. These were normally used to boot the computer and to diagnose problems.
