From en.wikipedia.org:
[12-bit computer from Digital] {{Infobox information appliance | name = PDP-5
| title = | aka = | logo = PDP-5 wordmark.svg | image = | image_size = |
caption = | developer = Digital Equipment Corporation | manufacturer = |
family = Programmed Data Processor | type = Minicomputer | generation = |
releasedate = [1963] | lifespan = | price = [27,000] | discontinued = |
unitssold = about 1,000<ref name=video-game-historian>{{cite web
|url=https://videogamehistorian.wordpress.com/tag/pdp-5 |title=PDP-5
Historical Interlude|date=11 December 2014 }} | unitsshipped = | media = | os
= | power = | soc = | cpu = | memory = | storage = | memory card = | display =
| graphics = | sound = | input = | controllers = | camera = | touchpad = |
connectivity = | platform = DEC 12-bit | service = | dimensions = | weight =
[540] | topgame = | compatibility = | predecessor = LINC | successor = PDP-8 |
related = | website = }} The PDP-5 was Digital Equipment Corporation's first
12-bit computer, introduced in 1963.<ref name=DEC57.PRES>{{cite book
|title=DIGITAL EQUIPMENT CORPORATION – Nineteen Fifty-Seven To The Present
|url=http://s3data.computerhistory.org/pdp-1/dec.digital_1957_to_the_present_(1978).1957-1978.102630349.pdf
|date=1975 |publisher=Digital Equipment Corporation}}[p.5]
** History
An earlier 12-bit computer, named LINC has been described as the first
minicomputer[1] and also "the first modern personal computer."[2] It had 2,048
12-bit words, and the first LINC was built in 1962.
DEC's founder, Ken Olsen, had worked with both it and a still earlier
computer, the 18-bit 64,000-word TX-0, at MIT's Lincoln Laboratory.
Neither of these machines was mass-produced.
** Applicability
Although the LINC computer was intended primarily for laboratory use, the
PDP-5's 12-bit system had a far wider range of use. An example of DEC's "The
success of the PDP-5 ... proved that a market for minicomputers did exist"
is:
- "Data-processing computers have accomplished for mathematicians what the wheel did for transportation" [3]
- "Very reliable data was obtained with ..." [4]
- "A PDP-5 computer was used very successfully aboard Evergreen [5] for ..." [6]
all of which described the same PDP-5 used by the United States Coast Guard.
The architecture of the PDP-5 was specified by Alan Kotok and Gordon Bell; the
principal logic designer was the young engineer Edson de Castro[7][8] who went
on later to found Data General.
** Hardware
By contrast with the 4-cabinet PDP-1,[9] the minimum configuration of the
PDP-5 was a single 19-inch cabinet with "150 printed circuit board modules
holding over 900 transistors."[10] Additional cabinets were required to house
many peripheral devices.
The minimum configuration weighed about [540].[11]
The machine was offered with from 1,024 to 32,768 12-bit words of core memory.
Addressing more than 4,096 words of memory required the addition of a Type 154
Memory Extension Control unit (in modern terms, a memory management unit);
this allowed adding additional Type 155 4,096 word core memory
modules.[12][13]
*** Instruction set
Of the 12 bits in each word, exactly 3 were used for instruction op-codes.<ref
name="DECpromo" />[14]
The PDP-5's instruction set was later expanded in its successor, the PDP-8.
The biggest change was that, in the PDP-5, the program counter was stored in
memory location zero, while on PDP-8 computers, it was a register inside the
CPU. Another significant change was that microcoded instructions on the PDP-5
could not combine incrementing and clearing the accumulator, while these could
be combined on the PDP-8. This allowed loading of many small constants in a
single instruction on the PDP-8. The PDP-5 was one of the first computer
series with more than 1,000 built.[15]<ref name=video-game-historian />
** Software
DEC provided an editor, an assembler, a FORTRAN II Compiler and DDT (a
debugger).<ref name="DECpromo" />
** Marketplace
With a base price of $27,000 and designed for those not in need of the 18-bit
PDP-4, yet having "applications needing solutions too complicated to be solved
efficiently by modules systems" the PDP-5, when introduced in 1963, came at a
time when the minicomputer market was gaining a foothold.[16]<ref
name=DEC57.PRES />
** Photos
- PDP-5 computer, including Teletype Model 33 ASR (see http://collection.maynardhistory.org/items/show/5708)
- PDP-5 from Ed Thelen's collection (see http://ed-thelen.org/comp-hist/vs-dec-pdp-5.jpg)
- Front panel of a PDP-5 (see http://www.mcmanis.com/chuck/computers/images/pdp5-panel.jpg)
** Notes
[group="NB"]
** References
[reflist]
[DEC hardware]
Category:DEC minicomputers Category:12-bit computers Category:Transistorized
computers Category:Computer-related introductions in 1963