The PDP-4, introduced in 1963, was DEC's second (and second 18-bit) computer system. It simplified both the instruction set and I/O architecture of the PDP-1 in order to reduce cost. About 45 PDP-4's were built.
Photographs (courtesy of Digital Equipment Corporation):
| Option | Description | Capacity |
| CPU and memory | PDP-4 | 4KW - 8KW |
| CPU options | Type 18 EAE, Extended Arithmetic Element | |
| Memory | 4K - 8K, 18b words | |
| Console | Type 65 KSR-28 Teletype (Baudot code) | |
| Paper tape | integral paper tape reader Type 75 paper tape punch |
|
| Real time clock | integral | |
| Line printer | Type 62 line printer (Hollerith code) | |
| DECtape | Type 550/555 DECtape | 148KW |
| Drum | Type 24 serial drum | 131KW |
Updated 30-Jan-2007 by Bob Supnik (simh AT trailing-edge DOT com - anti-spam encoded)
