PDP-8/A

The earliest PDP-8 model (informally known as a "Straight-8") used diode-transistor logic, packaged on flip chip cards, and was about the size of a minibar-fridge. This was followed by the PDP-8/S, available in desktop and rack-mount models. By using a one-bit serial ALU implementation, the PDP-8/S was smaller, less expensive, but vastly slower than the original PDP-8. The only mass storage peripheral available for the PDP-8/S was the DF32 disk. Later systems (the PDP-8/I and /L, the PDP-8/E, /F, and /M, and the PDP-8/A) returned to a faster, fully parallel implementation but used much less-expensive TTL MSI logic. Most surviving PDP-8s are from this era. The PDP-8/E is common, and well-regarded because so many types of I/O devices were available for it. It was often configured as a general-purpose computer.