The PDP-9, introduced in 1967, was DEC's fourth 18-bit computer system. It was upward compatible from the PDP-7, introducing a more advanced form of memory management. A cost-reduced version, the PDP-9/L, was introduced in 1968.
Photographs:
| Option | Description | Capacity |
| CPU and memory | PDP-9 | 4KW - 32KW |
| CPU options | KE09A EAE, extended arithmetic element | |
| KG09A memory extension control | ||
| KP09A power fail detection | ||
| KX09A memory protection control | ||
| Console | KSR-33 Teletype | |
| Additional terminals | LT09 and KSR-33 Teletypes | 1-4 lines |
| Paper tape | PC09A paper tape reader and punch | |
| Real time clock | integral | |
| Line printer | Type 647E line printer (sixbit ASCII) | |
| LP09 line printer (sevenbit ASCII) | ||
| DECtape | TC02/TU55 DECtape | 148KW |
| Disk | RF09/RS09 fixed head disk | 2.1MW |
| RB09 fixed head disk | 1MW | |
| Magnetic tape | TC59 magnetic tape (9 track only) |
Updated 08-Aug-2020 by Bob Supnik (simh AT groups DOT io - anti-spam encoded)
