From the PDP-1 handbook, 1960
The Programmed Data Processor (PDP-1) is a high speed, solid state digital computer designed to operate with many types of input-output devices with no internal machine changes. It is a single address, single instruction, stored program computer with powerful program features. Five-megacycle circuits, a magnetic core memory and fully parallel processing make possible a computation rate of 100,000 additions per second. The PDP-1 is unusually versatile. It is easy to install, operate and maintain. Conventional 110-volt power is used, neither air conditioning nor floor reinforcement is necessary, and preventive maintenance is provided for by built-in marginal checking circuits.
PDP-1 circuits are based on the designs of DEC’s highly successful and reliable System Modules. Flip-flops and most switches use saturating transistors. Primary active elements are Micro-Alloy-Diffused transistors. The entire computer occupies only 17 square feet of floor space. It consists of four equipment frames, one of which is used as the operating station.