1801 series CPU
Encyclopedia
For the 8-bit microprocessor family see RCA 1802
RCA 1802
The RCA CDP1802, also known as the COSMAC , is an 8-bit CMOS microprocessor introduced by RCA in early 1976. It is being by Intersil Corporation as a high-reliability microprocessor...



The 1801 series CPUs were a family of 16-bit
16-bit
-16-bit architecture:The HP BPC, introduced in 1975, was the world's first 16-bit microprocessor. Prominent 16-bit processors include the PDP-11, Intel 8086, Intel 80286 and the WDC 65C816. The Intel 8088 was program-compatible with the Intel 8086, and was 16-bit in that its registers were 16...

 Soviet
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 microprocessor
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...

s based on the indigenous Elektronika NC microarchitecture
Microarchitecture
In computer engineering, microarchitecture , also called computer organization, is the way a given instruction set architecture is implemented on a processor. A given ISA may be implemented with different microarchitectures. Implementations might vary due to different goals of a given design or...

 cores, but binary compatible with DEC's
Digital Equipment Corporation
Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...

 PDP-11
PDP-11
The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...

 machines. First released in 1980, various models and variants of the series were among the most popular Soviet microprocessors and dominated the embedded systems and military applications of the 80'es. They were also used in such widely different areas as graphing calculator
Graphing calculator
A graphing calculator typically refers to a class of handheld calculators that are capable of plotting graphs, solving simultaneous equations, and performing numerous other tasks with variables...

s (Elektronika MK-85) and industrial CNCs (Elektronika NC series), but arguably their most well-known use was in several Soviet general-purpose mini-
Minicomputer
A minicomputer is a class of multi-user computers that lies in the middle range of the computing spectrum, in between the largest multi-user systems and the smallest single-user systems...

 and microcomputer
Microcomputer
A microcomputer is a computer with a microprocessor as its central processing unit. They are physically small compared to mainframe and minicomputers...

 designs like SM EVM
SM EVM
SM EVM was the general name for several types of Soviet and Comecon minicomputers produced in the 1970s and 1980s. Production began in 1975....

 and DVK
DVK
DVK is a Soviet PDP-11-compatible personal computer.The design is also known as Elektronika MS-0501 and Elektronika MS-0502.Earlier models of DVK series were based on K1801VM1 or K1801VM2 microprocessors with 16 bit address bus. In the later models, the KM1801VM3 microprocessor was used.-...

, UKNC
UKNC
UKNC was a Soviet PDP-11-compatible educational computer, aimed at teaching school informatics courses. It is also known as Elektronika MS-0511...

 and BK
Elektronika BK
The Elektronika BK was a series of 16-bit PDP-11-compatible Soviet home computers developed by NPO Scientific Center, the leading Soviet microcomputer design team at the time. It was also responsible for the more powerful UKNC and DVK micros...

 families respectively. Due to being the CPU of the popular Elektronika BK
Elektronika BK
The Elektronika BK was a series of 16-bit PDP-11-compatible Soviet home computers developed by NPO Scientific Center, the leading Soviet microcomputer design team at the time. It was also responsible for the more powerful UKNC and DVK micros...

 home computer
Home computer
Home computers were a class of microcomputers entering the market in 1977, and becoming increasingly common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a single nontechnical user...

, used in its late years as a demo machine
Demoscene
The demoscene is a computer art subculture that specializes in producing demos, which are non-interactive audio-visual presentations that run in real-time on a computer...

, as well as DVK
DVK
DVK is a Soviet PDP-11-compatible personal computer.The design is also known as Elektronika MS-0501 and Elektronika MS-0502.Earlier models of DVK series were based on K1801VM1 or K1801VM2 microprocessors with 16 bit address bus. In the later models, the KM1801VM3 microprocessor was used.-...

 micros that often offered a first glimpse into the UNIX
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...

 world, this processor achieved something of a cult status among Soviet and then Russian programmers.

Development

The history of this CPU stems back from the early to mid-70'es, when the group of engineers in Zelenograd
Zelenograd
Zelenograd is a city, which, along with the territories and settlements under its jurisdiction, forms one of the administrative okrugs of Moscow - Zelenograd Administrative Okrug...

's Special Computing Center, led by D.I. Yuditsky, developed their first 16-bit minicomputer
Minicomputer
A minicomputer is a class of multi-user computers that lies in the middle range of the computing spectrum, in between the largest multi-user systems and the smallest single-user systems...

, called Elektronika NC-1. This machine, intended to directly compete with SM EVM
SM EVM
SM EVM was the general name for several types of Soviet and Comecon minicomputers produced in the 1970s and 1980s. Production began in 1975....

 series, was first released in 1973 and used the in-house developed sectioned 4-bit 587 CPU, sometimes called the first Soviet microprocessor ever. Its descendants proved popular and were widely used in various control systems and telecom equipment. However, sectioned nature of their CPUs made these machines somewhat unwieldy, especially in military applications, and the need for a single-crystal microprocessor was identified.

In 1980 the first 1801 CPU intended to fill this niche, K1801VE1, entered production. It was essentially a microcontroller
Microcontroller
A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM...

 with 256 byte
Byte
The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits. Historically, a byte was the number of bits used to encode a single character of text in a computer and for this reason it is the basic addressable element in many computer...

s of on-chip RAM
Ram
-Animals:*Ram, an uncastrated male sheep*Ram cichlid, a species of freshwater fish endemic to Colombia and Venezuela-Military:*Battering ram*Ramming, a military tactic in which one vehicle runs into another...

, 2K ROM
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...

 and other peripheral circuitry, still based on Elektronika NC instruction set
Instruction set
An instruction set, or instruction set architecture , is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O...

, but compatible with a Soviet clone of DEC's Q-Bus
Q-Bus
The Q-bus was one of several bus technologies used with PDP and MicroVAX computer systems manufactured by the Digital Equipment Corporation of Maynard, Massachusetts....

 that was already adopted as an industry standard—a first sign of the things to come. Its peripheral circuits were underutilized by the industry, as it was mostly used as a general-purpose CPU, rather than a microcontroller, so it was decided to simplify the chip, removing unnecessary devices from the die
Die (integrated circuit)
A die in the context of integrated circuits is a small block of semiconducting material, on which a given functional circuit is fabricated.Typically, integrated circuits are produced in large batches on a single wafer of electronic-grade silicon or other semiconductor through processes such as...

. But by that time its parent organization, the SCC, has already lost in powergames that plagued Soviet industry.

By its nature, Soviet industry was an extremely bureaucratic
Bureaucracy
A bureaucracy is an organization of non-elected officials of a governmental or organization who implement the rules, laws, and functions of their institution, and are occasionally characterized by officialism and red tape.-Weberian bureaucracy:...

 structure, so decision making process was often driven not by technical or economical considerations, but by the results of the games of influence between various organisations and officials. SCC, even despite its technical successes and popularity of its designs, was not without its opponents and even enemies. While its staff had an aversion to copying and reverse engineering
Reverse engineering
Reverse engineering is the process of discovering the technological principles of a device, object, or system through analysis of its structure, function, and operation...

 Western technology, many groups within the Ministry of Electronic Industry argued for it as a quicker and more secure way to meet the needs. These groups eventually prevailed, and in 1976 the SCC was essentially disbanded, its technical base passing to the Angstrem plant while some of its research labs were joined into Research Institute of Precise Technics (which didn't really need them), and other forming a research arm of the newly formed NPO Scientific Center.

This sudden reorganisation resulted in the abandonment of the Elektronika NC architecture (it continued only in CNCs based on an NC-1 machine, some of which are used up to this day) and adoption of the PDP-11 compatibility as a MEI standard, a process sometimes called PDP revolt in Russian literature. Thus, the microcode for the new simplified CPU was redesigned and made compatible with LSI-11 instruction set. New processor was released in 1982, designated K1801VM1. It was supplemented by the 600-gate KR1801VP1 ULA
Gate array
A gate array or uncommitted logic array is an approach to the design and manufacture of application-specific integrated circuits...

, which was used to implement various support circuitry, 64 Kib
Kibibit
The kibibit is a multiple of the bit, a unit of digital information storage, prefixed by the standards-based multiplier kibi , a binary prefix meaning 210...

 KR1801RE2 ROM
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...

 chip, and 64 Kib K573RF3 EPROM
EPROM
An EPROM , or erasable programmable read only memory, is a type of memory chip that retains its data when its power supply is switched off. In other words, it is non-volatile. It is an array of floating-gate transistors individually programmed by an electronic device that supplies higher voltages...

. Together they constituted the first widely used generation of 1801 family.

Technical characteristics

All CPUs in the family were single-crystal 16-bit
16-bit
-16-bit architecture:The HP BPC, introduced in 1975, was the world's first 16-bit microprocessor. Prominent 16-bit processors include the PDP-11, Intel 8086, Intel 80286 and the WDC 65C816. The Intel 8088 was program-compatible with the Intel 8086, and was 16-bit in that its registers were 16...

 microprocessor
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...

s based on Electronika NC microarchitecture
Microarchitecture
In computer engineering, microarchitecture , also called computer organization, is the way a given instruction set architecture is implemented on a processor. A given ISA may be implemented with different microarchitectures. Implementations might vary due to different goals of a given design or...

, however only the first one, K1801VE1 microcontroller
Microcontroller
A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM...

, used its own instruction set
Instruction set
An instruction set, or instruction set architecture , is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O...

. Others have updated microcode simulating LSI-11 architecture. Various models differed in clock speed, instruction set (first models lacked MUL and DIV commands, for example), package and address bus width (latest models supported 22-bit addressing).

K1801VE1

  • Instruction set: Elektronika NC
  • Technology: nMOS
    NMOS logic
    N-type metal-oxide-semiconductor logic uses n-type metal-oxide-semiconductor field effect transistors to implement logic gates and other digital circuits...

  • Bus: Q-bus
    Q-Bus
    The Q-bus was one of several bus technologies used with PDP and MicroVAX computer systems manufactured by the Digital Equipment Corporation of Maynard, Massachusetts....

    , multiplexed
  • Clock speed: 100 kHz — 2 MHz
  • Package: 42-pin ceramic planar, kind of cross between CERDIP and SOIC
    Small-Outline Integrated Circuit
    A small-outline integrated circuit is a surface-mounted integrated circuit package which occupies an area about 30–50% less than an equivalent DIP, with a typical thickness that is 70% less. They are generally available in the same pinouts as their counterpart DIP ICs...

  • Microcontroller
    Microcontroller
    A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM...

    • RAM
      Ram
      -Animals:*Ram, an uncastrated male sheep*Ram cichlid, a species of freshwater fish endemic to Colombia and Venezuela-Military:*Battering ram*Ramming, a military tactic in which one vehicle runs into another...

      : 256 byte
      Byte
      The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits. Historically, a byte was the number of bits used to encode a single character of text in a computer and for this reason it is the basic addressable element in many computer...

      s (128 16-bit words)
    • ROM
      Read-only memory
      Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...

      : 2 Kib
      Kibibit
      The kibibit is a multiple of the bit, a unit of digital information storage, prefixed by the standards-based multiplier kibi , a binary prefix meaning 210...

       (1024 16-bit words)

K1801VM1

  • Instruction set: LSI-11 (not including EIS)
  • Technology: nMOS
  • Die
    Die (integrated circuit)
    A die in the context of integrated circuits is a small block of semiconducting material, on which a given functional circuit is fabricated.Typically, integrated circuits are produced in large batches on a single wafer of electronic-grade silicon or other semiconductor through processes such as...

     size: 5x5 mm
    Millimetre
    The millimetre is a unit of length in the metric system, equal to one thousandth of a metre, which is the SI base unit of length....

    , 50000 transistor
    Transistor
    A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...

    s
  • Bus: МПИ (Q-Bus
    Q-Bus
    The Q-bus was one of several bus technologies used with PDP and MicroVAX computer systems manufactured by the Digital Equipment Corporation of Maynard, Massachusetts....

    , multiplexed)
  • Clock speed: 100 kHz — 5 MHz
  • Voltage: +5 V
    Volt
    The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...

  • Power: 1.2 W
    Watt
    The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...

  • Package: 42-pin ceramic planar



K1801VM2

  • Instruction set: LSI-11 (MUL/DIV included, FIS codes implemented by ROM interrupt routines)
  • Technology: nMOS
  • Die size: 5.3x5.35 mm, 120000 transistors
  • Bus: МПИ (Q-Bus
    Q-Bus
    The Q-bus was one of several bus technologies used with PDP and MicroVAX computer systems manufactured by the Digital Equipment Corporation of Maynard, Massachusetts....

    , multiplexed)
  • Clock speed: 2 — 10 MHz
  • Voltage: +5 V
  • Power: 1.7 W
  • Package: 40-pin CERDIP(KM1801VM2)/PDIP(KR1801VM2)


It has two different address spaces and the ability to quickly switch between them. They were used in implementing the FIS instruction subset, with instructions processed not in microcode, but as interrupt handlers in shadow ROM.

1806VM2 (N1806VM2)

  • Technology: CMOS
    CMOS
    Complementary metal–oxide–semiconductor is a technology for constructing integrated circuits. CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits...

  • Clock speed: 0 — 5 MHz
  • Voltage: +5.5 V
  • Package: 42-pin ceramic planar (1806VM2) or 64-pin CQFP
    QFP
    A QFP or Quad Flat Package is a surface mount integrated circuit package with leads extending from each of the four sides. Socketing such packages is rare and hole mounting is not possible. Versions ranging from 32 to 304 pins with a pitch ranging from 0.4 to 1.0 mm are common...

     (N1806VM2)

T36VM1-2 (KA1013VM1)

Microcontroller
Microcontroller
A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM...

. It uses an 1806 core with support logic implemented in ULAs placed on the same die. Includes keyboard controller
Keyboard controller (computing)
In computing, a keyboard controller is a device which interfaces a keyboard to a computer. Its main function is to inform the computer when a key is pressed or released...

, UART, parallel interface, MMU
Memory management unit
A memory management unit , sometimes called paged memory management unit , is a computer hardware component responsible for handling accesses to memory requested by the CPU...

, watchdog timer and PMU
Power Management Unit
The Power Management Unit is a microcontroller that governs power functions of digital platforms. This microchip has many similar components to the average computer, including firmware and software, memory, a CPU, input/output functions, timers to measure intervals of time, as well as analog to...

. Memory
Memory
In psychology, memory is an organism's ability to store, retain, and recall information and experiences. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing memory....

 is external.

K1801VM3 (N1801VM3)

  • Instruction set: LSI-11 (EIS and MMU included)
  • Technology: nMOS
  • Die size: 6.65x8 mm, 200000 transistors
  • Bus: МПИ (Q-Bus
    Q-Bus
    The Q-bus was one of several bus technologies used with PDP and MicroVAX computer systems manufactured by the Digital Equipment Corporation of Maynard, Massachusetts....

    , multiplexed)
  • Clock speed: 4 — 6 MHz, and 8 MHz from 1991
  • Voltage: +5 V
  • Power: 1.7 W
  • Package: 64-pin CERDIP(K1801VM3)/64-pin CQFP(N1801VM3)
  • Address bus: 22-bit
  • Supports floating point
    Floating point
    In computing, floating point describes a method of representing real numbers in a way that can support a wide range of values. Numbers are, in general, represented approximately to a fixed number of significant digits and scaled using an exponent. The base for the scaling is normally 2, 10 or 16...

     coprocessor
    Coprocessor
    A coprocessor is a computer processor used to supplement the functions of the primary processor . Operations performed by the coprocessor may be floating point arithmetic, graphics, signal processing, string processing, or encryption. By offloading processor-intensive tasks from the main processor,...


KA1801VM4 (KN1801VM4)

Floating point coprocessor for VM3, 32/64 bit, clocked at 6 MHz (8MHz after 1991)
  • DEC
    Digital Equipment Corporation
    Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...

     PDP-11
    PDP-11
    The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...

     FPU
    Floating point unit
    A floating-point unit is a part of a computer system specially designed to carry out operations on floating point numbers. Typical operations are addition, subtraction, multiplication, division, and square root...

     instructions LDUB, LDSC, STA0, STB0 and STQ0 have not been implemented.

Use

These CPUs were used in:
  • Soyuz-Neon PC-11/16 PC, roughly similar to AT in performance (N1806VM2)
  • DVK
    DVK
    DVK is a Soviet PDP-11-compatible personal computer.The design is also known as Elektronika MS-0501 and Elektronika MS-0502.Earlier models of DVK series were based on K1801VM1 or K1801VM2 microprocessors with 16 bit address bus. In the later models, the KM1801VM3 microprocessor was used.-...

     series professional micros (various)
  • UKNC
    UKNC
    UKNC was a Soviet PDP-11-compatible educational computer, aimed at teaching school informatics courses. It is also known as Elektronika MS-0511...

     educational computers (KM1801VM2)
  • BK
    Elektronika BK
    The Elektronika BK was a series of 16-bit PDP-11-compatible Soviet home computers developed by NPO Scientific Center, the leading Soviet microcomputer design team at the time. It was also responsible for the more powerful UKNC and DVK micros...

     home computers (KM1801VM1)
  • Elektronika NC-31 lathe
    Lathe
    A lathe is a machine tool which rotates the workpiece on its axis to perform various operations such as cutting, sanding, knurling, drilling, or deformation with tools that are applied to the workpiece to create an object which has symmetry about an axis of rotation.Lathes are used in woodturning,...

    -control CNC
  • "Romashka" electronic typewriter
    Typewriter
    A typewriter is a mechanical or electromechanical device with keys that, when pressed, cause characters to be printed on a medium, usually paper. Typically one character is printed per keypress, and the machine prints the characters by making ink impressions of type elements similar to the pieces...

  • Various military and industrial applications
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK