PDP-4

Last updated
PDP-4 computer Photograph of Exhibit of PDP-4 Digital Equipment Corporation Machines on the Stage of the National Archives Auditorium, 1964 (3874706978).jpg
PDP-4 computer

The PDP-4 was the successor to the Digital Equipment Corporation's PDP-1.

Contents

History

This 18-bit machine, first shipped in 1962, [1] was a compromise: "with slower memory and different packaging" than the PDP-1, but priced at $65,000 - less than half the price of its predecessor. [2] :p.4 All later 18-bit PDP machines (7, 9 and 15) are based on a similar, but enlarged instruction set, more powerful than, but based on the same concepts as, the 12-bit PDP-5/PDP-8 series.

Approximately 54 were sold. [2]

Hardware

The system's memory cycle was 8 microseconds, compared to 5 microseconds for the PDP-1. [3] [4]

The PDP-4 weighed about 1,090 pounds (490 kg). [5]

Mass storage

Both the PDP-1 and the PDP-4 were introduced as paper tape-based systems. [6] The only use, if any, for IBM-compatible 200 BPI or 556 BPI magnetic tape [7] was for data. The use of "mass storage" drums - not even a megabyte and non-removable - were an available option, but were not in the spirit of the “personal” or serially shared systems that DEC offered.

It was in this setting that DEC introduced DECtape, initially called "MicroTape", for both the PDP-1 and PDP-4.

Software

DEC provided an editor, an assembler, and a FORTRAN II compiler. [3] The assembler was different from that of the PDP-1 in two ways:

The PDP-4's console typewriter was a Teletype Model 28 ASR, with a built in paper tape reader and paper tape punch. Teletype Model 28 KSR Keyboard.png
The PDP-4's console typewriter was a Teletype Model 28 ASR, with a built in paper tape reader and paper tape punch.

Photos

See also

Related Research Articles

PDP-10 36 bit mainframe computer family built 1966–1983

Digital Equipment Corporation (DEC)'s PDP-10, later marketed as the DECsystem-10, is a mainframe computer family manufactured beginning in 1966 and discontinued in 1983. 1970s models and beyond were marketed under the DECsystem-10 name, especially as the TOPS-10 operating system became widely used.

Programmed Data Processor Name used for several lines of minicomputers

Programmed Data Processor (PDP), referred to by some customers, media and authors as "Programmable Data Processor, is a term used by the Digital Equipment Corporation from 1957 to 1990 for several lines of minicomputers. The name "PDP" intentionally avoids the use of the term "computer" because, at the time of the first PDPs, computers had a reputation of being large, complicated, and expensive machines, and the venture capitalists behind Digital would not support Digital's attempting to build a "computer"; the word "minicomputer" had not yet been coined. So instead, Digital used their existing line of logic modules to build a Programmed Data Processor and aimed it at a market that could not afford the larger computers.

PDP-1

The PDP-1 is the first computer in Digital Equipment Corporation's PDP series and was first produced in 1959. It is famous for being the computer most important in the creation of hacker culture at MIT, BBN and elsewhere. The PDP-1 is the original hardware for playing history's first game on a minicomputer, Steve Russell's Spacewar!

PDP-8 First commercially successful minicomputer

The PDP-8 is a 12-bit minicomputer that was produced by Digital Equipment Corporation (DEC). It was the first commercially successful minicomputer, with over 50,000 units being sold over the model's lifetime. Its basic design follows the pioneering LINC but has a smaller instruction set, which is an expanded version of the PDP-5 instruction set. Similar machines from DEC are the PDP-12 which is a modernized version of the PDP-8 and LINC concepts, and the PDP-14 industrial controller system.

PDP-11 Series of 16-bit minicomputers

The PDP-11 is a series of 16-bit minicomputers sold by Digital Equipment Corporation (DEC) from 1970 into the 1990s, one of a succession of products in the PDP series. In total, around 600,000 PDP-11s of all models were sold, making it one of DEC's most successful product lines. The PDP-11 is considered by some experts to be the most popular minicomputer ever.

PDP-7

The PDP-7 was a minicomputer produced by Digital Equipment Corporation as part of the PDP series. Introduced in 1964, shipped since 1965, it was the first to use their Flip-Chip technology. With a cost of US$72,000, it was cheap but powerful by the standards of the time. The PDP-7 is the third of Digital's 18-bit machines, with essentially the same instruction set architecture as the PDP-4 and the PDP-9.

RSX-11 operating system

RSX-11 is a discontinued family of multi-user real-time operating systems for PDP-11 computers created by Digital Equipment Corporation. In widespread use through the late 1970s and early 1980s, RSX-11 was influential in the development of later operating systems such as VMS and Windows NT. It was designed for process control, but was also popular for program development.

LINC Minicomputer

The LINC is a 12-bit, 2048-word transistorized computer. The LINC is considered by some the first minicomputer and a forerunner to the personal computer. Originally named the "Linc", suggesting the project's origins at MIT's Lincoln Laboratory, it was renamed LINC after the project moved from the Lincoln Laboratory. The LINC was designed by Wesley A. Clark and Charles Molnar.

PDP-6

The PDP-6 is a computer model developed by Digital Equipment Corporation (DEC) in 1964. It was influential primarily as the prototype (effectively) for the later PDP-10; the instruction sets of the two machines are almost identical.

OS/8 was the primary operating system used on the Digital Equipment Corporation's PDP-8 minicomputer.

DECtape

DECtape, originally called Microtape, is a magnetic tape data storage medium used with many Digital Equipment Corporation computers, including the PDP-6, PDP-8, LINC-8, PDP-9, PDP-10, PDP-11, PDP-12, and the PDP-15. On DEC's 32-bit systems, VAX/VMS support for it was implemented but did not become an official part of the product lineup.

The PDP-9, the 4th of the five 18-bit minicomputers produced by Digital Equipment Corporation, was introduced in 1966. A total of 445 PDP-9 systems were produced, of which 40 were the compact, low-cost PDP-9/L units.

The PDP-5 was Digital Equipment Corporation's first 12-bit computer, introduced in 1963.

PDP-15

The PDP-15 was the fifth and last of the 18-bit minicomputers produced by Digital Equipment Corporation. The PDP-1 was first delivered in December 1959 and the first PDP-15 was delivered in February 1970. More than 400 of these successors to the PDP-9 were ordered within the first eight months.

The Massbus is a high-performance computer input/output bus designed in the 1970s by Digital Equipment Corporation (DEC).

In computer architecture, 18-bit integers, memory addresses, or other data units are those that are 18 bits wide. Also, 18-bit CPU and ALU architectures are those that are based on registers, address buses, or data buses of that size.

The PDP-11 architecture is an instruction set architecture (ISA) developed by Digital Equipment Corporation (DEC). It is implemented by central processing units (CPUs) and microprocessors used in PDP-11 minicomputers. It was in wide use during the 1970s, but was eventually overshadowed by the more powerful VAX-11 architecture in the 1980s.

PDP-8/E

The PDP-8/e was a model of the PDP-8 line of minicomputers, designed by the Digital Equipment Corporation to be a general purpose computer that inexpensively met the needs of the average user while also being capable of modular expansion to meet the more specific needs of advanced user. The first was built in 1970 and was among the first ever minicomputers and this one was small enough to fit in the back seat of a Volkswagen Beetle Convertible. It originally sold for $6,500 but after 18 months the price dropped to $4995 to make it the only computer under $5000 available at that time.

Digital Equipment Corporation (DEC), was a major American company in the computer industry. Founded in 1957 with $70,000 of venture capital, it became "the nation's second-largest computer company, after IBM." Its initial major impact was in minicomputers, but its later-introduced VAX and Alpha systems are still notable.

Philco was one of the pioneers of transistorized computers. After the company developed the surface barrier transistor, which was much faster than previous point-contact types, it was awarded contracts for military and government computers. Commercialized derivatives of some of these designs became successful business and scientific computers. The TRANSAC Model S-1000 was released as a scientific computer. The TRANSAC S-2000 mainframe computer system was first produced in 1958, and a family of compatible machines, with increasing performance, was released over the next several years.

References

  1. Robert Slater (1989). Portraits in Silicon. p.  210. ISBN   0262691310.
  2. 1 2 DIGITAL EQUIPMENT CORPORATION - Nineteen Fifty-Seven To The Present (PDF). Digital Equipment Corporation. 1975.
  3. 1 2 Paul E. Ceruzzi (2012). A History of Modern Computing . p.  209. ISBN   0262532034.
  4. Bell, C. Gordon; Mudge, J. Craig; McNamara, John E. (2014). Computer Engineering: A DEC View of Hardware Systems Design. ISBN   1483221105.
  5. Weik, Martin H. (Jan 1964). "PROGRAMMED DATA PROCESSOR 4". ed-thelen.org. A Fourth Survey of Domestic Electronic Digital Computing Systems.
  6. Bob Supnik. "Architectural Evolution in DEC's 18b Computers" (PDF).
  7. Brochure F-71 - "Programmed Data Processor - 7" (PDF). Digital Equipment Corporation. 1964.