Difference between revisions of "PDP-8"
(for the 2 MHz clock, see "Computer Structures: Readings and Examples", page 120: "A PDP-S/S is one-fifteenth of a PDP-8 at one-half the cost. ...even though the same 2-megahertz logic clock is used in both cases.") |
(fpund good sources (primarily maintenance manual) that clarifies this) |
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| virtual address = 4k words | | virtual address = 4k words | ||
| design type = [[clock]]ed random [[logic]] | | design type = [[clock]]ed random [[logic]] | ||
| − | | clock speed = | + | | clock speed = 1.33 MHz |
| − | |||
| memory speed = 1.5 μseconds | | memory speed = 1.5 μseconds | ||
| memory mgmt = bank select | | memory mgmt = bank select | ||
Revision as of 21:24, 19 August 2019
This article is about the first PDP-8, which had that name without a model suffix. For information about PDP-8's in general, see PDP-8 family.
| PDP-8 | |
 An original, transistorized PDP-8 | |
| Manufacturer: | DEC |
|---|---|
| Architecture: | PDP-8 |
| Year Introduced: | 1965 |
| Year Discontinued: | 1969 |
| Form Factor: | minicomputer |
| Word Size: | 12 bits |
| Logic Type: | DTL |
| Design Type: | clocked random logic |
| Clock Speed: | 1.33 MHz |
| Memory Speed: | 1.5 μseconds |
| Physical Address Size: | 32k words (requires optional Type 183) |
| Virtual Address Size: | 4k words |
| Memory Management: | bank select |
| Bus Architecture: | Negative I/O Bus |
| Predecessor(s): | PDP-5 |
| Successor(s): | PDP-8/I |
| Price: | US$18,500 |
The PDP-8 (now often known as a Straight 8; the name dates from the late 60's, apparently adopted to allow disambiguation), the first model of the PDP-8 family, was DEC's major breakthrough, and now considered the first really successful minicomputer. It was, by a significant amount, the cheapest computer yet made at the time.
The PDP-8 was constructed with discrete transistors, packaged into DEC's FLIP CHIP technology. It could perform an addition to the accumulator in 3.0 μseconds, and a 12 by 12 bit multiplication with 24 bit result in 15 μseconds (average; range 9 to 21), using the optional math extension hardware (below).
Options
Options included:
- Type 183 Memory Extension Control, which was needed to support more than 4k words of memory
- Type 184 Memory Module
- Type 188 Memory Parity
- Type 182 Extended Arithmetic Element, which supported hardware integer multiplication and division, multi-bit double-word shifts, and normalization
Operating Systems
The PDP-8 could run various operating systems including:
Emulators
There are various emulators for PDP-8 systems including:
Application software/Simulation software
Mention in this video regarding a PDP-8 screen running J.H. Conways game of life:
| v • d • e PDP-8 Computers, Software and Peripherals |
|---|
| PDP-8s: PDP-5 • PDP-8 • LINC-8 • PDP-8/S • PDP-8/I • PDP-8/L • PDP-12 • PDP-8/E • PDP-8/F • PDP-8/M • PDP-8/A
Workstations: VT78 Also: PDP-8 family • PDP-8 architecture • PDP-8 Memory Extension units |
