This was a 12-bit design adapted from the 1962 LINC machine that was intended to be used in a lab setting.
It is commonly stated that the C programming language took advantage of several low-level PDP-11–dependent programming features, albeit not originally by design. An effort to expand the PDP-11 from 16 to 32-bit addressing led to the VAX-11 design, which took part of its name from the PDP-11. == History == ===Previous machines=== In 1963, DEC introduced what is considered to be the first commercial minicomputer in the form of the PDP-5.
In 1967–1968, DEC engineers designed a 16-bit machine, the PDP-X, but management ultimately canceled the project as it did not appear to offer a significant advantage over their existing 12- and 18-bit platforms. Several of the engineers from the PDP-X left DEC and formed Data General.
The PDP-11 is a series of 16-bit minicomputers sold by Digital Equipment Corporation (DEC) from 1970 into the 1990s, one of a set of products in the Programmed Data Processor (PDP) series.
The first officially named version of Unix ran on the PDP-11/20 in 1970.
The Nova was a major success, selling tens of thousands of units and launching what would become one of DEC's major competitors through the 1970s and 1980s. ===Release=== A subsequent effort, code-named "Desk Calculator", looked at a variety of options before choosing what became the 16-bit PDP-11; The PDP-11 family was announced in January 1970 and shipments began early that year.
DEC sold over 170,000 PDP-11s in the 1970s. Initially manufactured of small-scale transistor–transistor logic, a single-board large scale integration version of the processor was developed in 1975.
As the architecture evolved, there were also variations in handling of some processor status and control registers. === Unibus models === The following models use the Unibus as their principal bus: PDP-11/20 and PDP-11/15 — 1970.
Microprogrammed successors to the PDP-11/20; the design team was led by Jim O'Loughlin. PDP-11/05 and PDP-11/10 – 1972.
First model to support an optional FP11 floating-point coprocessor, which established the format used in later models. PDP-11/35 and PDP-11/40 – 1973.
DEC sold over 170,000 PDP-11s in the 1970s. Initially manufactured of small-scale transistor–transistor logic, a single-board large scale integration version of the processor was developed in 1975.
It used a wire-wrapped backplane. == LSI-11 == The LSI-11 (PDP-11/03), introduced in February 1975 is the first PDP-11 model produced using large-scale integration; the entire CPU is contained on four LSI chips made by Western Digital (the MCP-1600 chip set; a fifth chip can be added to extend the instruction set, as pictured on the right).
A cost-reduced successor to the PDP-11/20. PDP-11/70 – 1975.
The PDP-11/34a (1978) supports a fast floating-point option, and the 11/34c (same year) supported a cache memory option. PDP-11/60 – 1977.
A two-or-three-chip processor, the J-11 was developed in 1979.
A PDP-11 with user-writable microcontrol store; this was designed by another team led by Jim O'Loughlin. PDP-11/44 – 1979.
It was also the last PDP-11 architecture created by Digital Equipment Corporation, later models were VLSI chip realizations of the existing system architectures. PDP-11/24 – 1979.
The Nova was a major success, selling tens of thousands of units and launching what would become one of DEC's major competitors through the 1970s and 1980s. ===Release=== A subsequent effort, code-named "Desk Calculator", looked at a variety of options before choosing what became the 16-bit PDP-11; The PDP-11 family was announced in January 1970 and shipments began early that year.
The early VAX CPUs provided a PDP-11 compatibility mode under which much existing software could be immediately used, in parallel with newer 32-bit software, but this capability was dropped with the first MicroVAX. For a decade, the PDP-11 was the smallest system that could run Unix, but in the 1980s, the IBM PC and its clones largely took over the small computer market; BYTE in 1984 reported that the PC's Intel 8088 microprocessor could outperform the PDP-11/23 when running Unix.
A replacement for the 11/45 and 11/70, introduced in 1980, that supports optional (though apparently always included) cache memory, FP-11 floating-point processor (one circuit board, using sixteen AMD Am2901 bit slice processors), and commercial instruction set (CIS, two boards).
In the 1980s, the UK's air traffic control radar processing was conducted on a PDP 11/34 system known as PRDS – Processed Radar Display System at RAF West Drayton.
In the early years, in particular, Microsoft's Xenix was ported to systems like the TRS-80 Model 16 (with up to 1 MB of memory) in 1983, and to the Apple Lisa, with up to 2 MB of installed RAM, in 1984.
The early VAX CPUs provided a PDP-11 compatibility mode under which much existing software could be immediately used, in parallel with newer 32-bit software, but this capability was dropped with the first MicroVAX. For a decade, the PDP-11 was the smallest system that could run Unix, but in the 1980s, the IBM PC and its clones largely took over the small computer market; BYTE in 1984 reported that the PC's Intel 8088 microprocessor could outperform the PDP-11/23 when running Unix.
In the early years, in particular, Microsoft's Xenix was ported to systems like the TRS-80 Model 16 (with up to 1 MB of memory) in 1983, and to the Apple Lisa, with up to 2 MB of installed RAM, in 1984.
First VLSI PDP-11 for Unibus, using the "Fonz-11" (F11) chip set with a Unibus adapter. PDP-11/84 – 1985-1986.
When VT173 inventory was exhausted in 1985, Digital discontinued DECset and transferred its customer agreements to Datalogics.
The PDP-11 is a series of 16-bit minicomputers sold by Digital Equipment Corporation (DEC) from 1970 into the 1990s, one of a set of products in the Programmed Data Processor (PDP) series.
The last models of the PDP-11 line were the PDP-11/94 and PDP-11/93 introduced in 1990. == Innovative features == === Instruction set orthogonality === The PDP-11 processor architecture has a mostly orthogonal instruction set.
Other companies found a niche market for replacements for legacy PDP-11 processors, disk subsystems, etc. By the late 1990s, not only DEC but most of the New England computer industry which had been built around minicomputers similar to the PDP-11 collapsed in the face of microcomputer-based workstations and servers. == Models == The PDP-11 processors tend to fall into several natural groups depending on the original design upon which they are based and which I/O bus they use.
Using the VLSI "Jaws-11" (J11) chip set with a Unibus adapter. PDP-11/94 – 1990.
A line of personal computers based on the PDP-11, the DEC Professional series, failed commercially, along with other non-PDP-11 PC offerings from DEC. In 1994, DEC sold the PDP-11 system-software rights to Mentec Inc., an Irish producer of LSI-11 based boards for Q-Bus and ISA architecture personal computers, and in 1997 discontinued PDP-11 production.
A line of personal computers based on the PDP-11, the DEC Professional series, failed commercially, along with other non-PDP-11 PC offerings from DEC. In 1994, DEC sold the PDP-11 system-software rights to Mentec Inc., an Irish producer of LSI-11 based boards for Q-Bus and ISA architecture personal computers, and in 1997 discontinued PDP-11 production.
As such, they were in use until their software was rendered inoperable by the Year 2000 problem.
The US Navy used a PDP-11/34 to control its Multi-station Spatial Disorientation Device, a simulator used in pilot training, until 2007, when it was replaced by a PC-based emulator that could run the original PDP-11 software and interface with custom Unibus controller cards. A PDP-11/45 was used for the experiment that discovered the J/ψ meson at the Brookhaven National Laboratory.
The software for the Therac-25 medical linear particle accelerator also ran on a 32K PDP 11/23. In 2013, it was reported that PDP-11 programmers would be needed to control nuclear power plants through 2050. Another use was for storage of test programs for Teradyne ATE equipment, in a system known as the TSD (Test System Director).
All text is taken from Wikipedia. Text is available under the Creative Commons Attribution-ShareAlike License .
Page generated on 2021-08-05