PDP-9
| PDP-9 | |
| Manufacturer: | Digital Equipment Corporation |
|---|---|
| Year First Shipped: | 1966 |
| Form Factor: | minicomputer |
| Word Size: | 18 bits |
| Logic Type: | PNP Transistor FLIP CHIPs |
| Design Type: | microcoded |
| Memory Speed: | 1 μsec |
| Physical Address Size: | 15 bits (32K words) |
| Virtual Address Size: | 13 bits (direct), 15 bits (extended) |
| Memory Management: | bounds register |
| Predecessor(s): | PDP-7 |
| Successor(s): | PDP-15 |
| Price: | US$30K (8KW system) |
The PDP-9 was DEC's fourth 18-bit computer, and the first DEC CPU to use microcode. A little over 400 were built.
Its principal intended use was for real-time systems, including data recording and process control. A variety of models were offered; the basic system provided 8K words of core memory, and the PDP-9/L was a cost-reduced system with cheaper peripherals and 4KW of memory.
Instructions had a 4-bit opcode, 1 bit of indirect, and 13 bits of address. It was a load-store architecture, with a single accumulator. Multiply/divide was a hardware option, the KE09A, which also performed shifting.
Use of more than 8KW of main memory required the Memory Extension Control, KG09A. A memory management option, the KX09A, which included a boundary register to set the boundary between protected and un-protected memory, and two modes for the CPU, was also available.
A large range of peripherals were available, including DECtape (via the TC02 controller), magnetic tape (via the TC59), drum (RM09 controller) and fixed-head disk (RB09).
Further Reading
(All available online through BitSavers.)
- "PDP-9 User Handbook"
