PDP-8/I: Difference between revisions

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Introduced in 1968 as the successor to the PDP-8, the PDP-8/I was constructed out of integrated circuits on M-class [[Flip-chips]].
{{Infobox Machine
| name = PDP-8/I
<!--
| image = PDP 8 e Trondheim.jpg
| caption = PDP-8/E front panel
| ram = Maximum of 32 kwords in eight 4 kword banks
-->
| year introduced = 1968
| form factor = [[minicomputer]]
| word size = 12
| physical address = 32KW (requires optional MC8/I)
| virtual address = 4KW
| logic type = [[Transistor-transistor logic|TTL]]
| design type = [[clock]]ed random [[logic]]
| clock speed = 333KHz
| memory speed = 1.5 μseconds
| bus arch = negative I/O bus
| memory mgmt = bank selection, CPU mode
| operating system = [[TSS/8]]. Disk Monitor System
| predecessor = [[PDP-8]]
| successor = [[PDP-8/E]]
}}
 
The '''PDP-8/I''' was introduced in 1968 as the successor to the [[PDP-8]]. It was constructed out of [[Transistor-transistor logic|TTL]] [[integrated circuit|ICs]] on M-class [[FLIP CHIP]]s.
 
Options included:
 
* KA8/IB Positive I/O Bus Interface, to allow use of newer PDP-8 devices
* MC8/I Memory Extension Control, which was needed to support more than 4K [[word]]s of memory
* MP8/I Memory Parity
* KE8/I Extended Arithmetic Element, which supported [[hardware]] integer multiplication and division, one-[[bit]] double-word shifts, and [[normalization]]
* KT8/I Time Sharing Hardware Modification, which allowed the computer to operate in either Executive Mode or User Mode
 
It could perform an addition to the [[accumulator]] in 3.0 μseconds, and a 12 by 12 bit multiplication with 24 bit result in 6.0 μseconds, using the math extension hardware.


{{Nav PDP-8}}
{{Nav PDP-8}}

Revision as of 00:31, 4 September 2018


PDP-8/I
Year Introduced: 1968
Form Factor: minicomputer
Word Size: 12
Logic Type: TTL
Design Type: clocked random logic
Clock Speed: 333KHz
Memory Speed: 1.5 μseconds
Physical Address Size: 32KW (requires optional MC8/I)
Virtual Address Size: 4KW
Memory Management: bank selection, CPU mode
Bus Architecture: negative I/O bus
Operating System: TSS/8. Disk Monitor System
Predecessor(s): PDP-8
Successor(s): PDP-8/E


The PDP-8/I was introduced in 1968 as the successor to the PDP-8. It was constructed out of TTL ICs on M-class FLIP CHIPs.

Options included:

  • KA8/IB Positive I/O Bus Interface, to allow use of newer PDP-8 devices
  • MC8/I Memory Extension Control, which was needed to support more than 4K words of memory
  • MP8/I Memory Parity
  • KE8/I Extended Arithmetic Element, which supported hardware integer multiplication and division, one-bit double-word shifts, and normalization
  • KT8/I Time Sharing Hardware Modification, which allowed the computer to operate in either Executive Mode or User Mode

It could perform an addition to the accumulator in 3.0 μseconds, and a 12 by 12 bit multiplication with 24 bit result in 6.0 μseconds, using the math extension hardware.