Microprocessor development board
Encyclopedia
A microprocessor development board is a printed circuit board containing a microprocessor
and the minimal support logic needed for an engineer to become acquainted with the microprocessor on the board, and to learn to program it. It also served users of the microprocessor as a method to prototype applications in products.
Unlike a general-purpose system such as a home computer
, usually a development board contains little or no hardware dedicated to a user interface. It will have some provision to accept and run a user-supplied program, such as downloading a program through a serial port
to flash memory
, or some form of programmable memory
in a socket in earlier systems.
Microprocessor training development kits were not always produced by microprocessor manufacturers. Many systems that can be classified as microprocessor development kits were produced by third parties, one example is the Sinclair MK14
, which was inspired by the official SC/MP development board from National Semiconductor
, the "NS introkit".
Although these development boards were not designed for hobbyists, they were often bought by them because they were the earliest cheap microcomputer devices you could buy. They often added all kinds of expansions, such as more memory, a video interface etc. It was very popular to use (or write) an implementation of Tiny Basic
. The most popular microprocessor board, the KIM-1
, received the most attention from the hobby community, because it was much cheaper than most other development boards, and you could get more software for it (Tiny Basic, games, assemblers), and cheap expansion cards to add more memory or other functionality. Also much more articles were published in magazines like "Kilobaud Microcomputing" that described home-brew software and hardware for the KIM-1 you could copy than for other development boards.
Today some chip producers still release "test boards" to demonstrate their chips, and to use them as a "reference design
". Their significance these days is much smaller than it was in the days that such boards, (the KIM-1
being the canonical
example) were the only low cost way to get "hands-on" acquainted with microprocessors..
Input was normally done with a hexadecimal keyboard, using a machine language monitor program, and the display only consisted of a 7-segment display. Backup storage of written assembler programs was primitive: only a cassette type interface was typically provided, or the serial telex interface was used to read (or punch) a papertape.
Often the board has some kind to expansion connector that brought out all the necessary CPU signals, so that an engineer could build and test an experimental interface or other electronic device.
External interfaces on the bare board were often limited to an RS232 serial port, so a terminal, printer, or teletypewriter could be connected.
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...
and the minimal support logic needed for an engineer to become acquainted with the microprocessor on the board, and to learn to program it. It also served users of the microprocessor as a method to prototype applications in products.
Unlike a general-purpose system such as a 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...
, usually a development board contains little or no hardware dedicated to a user interface. It will have some provision to accept and run a user-supplied program, such as downloading a program through a serial port
Serial port
In computing, a serial port is a serial communication physical interface through which information transfers in or out one bit at a time...
to flash memory
Flash memory
Flash memory is a non-volatile computer storage chip that can be electrically erased and reprogrammed. It was developed from EEPROM and must be erased in fairly large blocks before these can be rewritten with new data...
, or some form of programmable memory
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...
in a socket in earlier systems.
History
The reason for the existence of a development board was only to provide a system for learning to use a new microprocessor, not for entertainment. So everything superfluous was left out to keep costs down. Even an enclosure was not supplied, nor a power supply. This is because the board would only be used in a "laboratory" environment so it did not need an enclosure, and the board could be powered by a typical bench power supply already available to an electronic engineer.Microprocessor training development kits were not always produced by microprocessor manufacturers. Many systems that can be classified as microprocessor development kits were produced by third parties, one example is the Sinclair MK14
MK14
The Microcomputer Kit 14, or MK14 was a computer kit sold by Science of Cambridge of the United Kingdom, first introduced in 1977 for UK£39.95. The MK14 eventually sold over 50,000 units. It used a National Semiconductor SC/MP CPU , 256 bytes of random access memory which was directly expandable...
, which was inspired by the official SC/MP development board from National Semiconductor
National Semiconductor
National Semiconductor was an American semiconductor manufacturer, that specialized in analog devices and subsystems,formerly headquartered in Santa Clara, California, USA. The products of National Semiconductor included power management circuits, display drivers, audio and operational amplifiers,...
, the "NS introkit".
Although these development boards were not designed for hobbyists, they were often bought by them because they were the earliest cheap microcomputer devices you could buy. They often added all kinds of expansions, such as more memory, a video interface etc. It was very popular to use (or write) an implementation of Tiny Basic
Tiny BASIC
Tiny BASIC is a dialect of the BASIC programming language that can fit into as little as 2 or 3 KB of memory. This small size made it invaluable in the early days of microcomputers , when typical memory size was only 4–8 KB.- History :...
. The most popular microprocessor board, the KIM-1
KIM-1
The KIM-1, short for Keyboard Input Monitor, was a small 6502-based single-board computer developed and produced by MOS Technology, Inc. and launched in 1976...
, received the most attention from the hobby community, because it was much cheaper than most other development boards, and you could get more software for it (Tiny Basic, games, assemblers), and cheap expansion cards to add more memory or other functionality. Also much more articles were published in magazines like "Kilobaud Microcomputing" that described home-brew software and hardware for the KIM-1 you could copy than for other development boards.
Today some chip producers still release "test boards" to demonstrate their chips, and to use them as a "reference design
Reference design
Reference design refers to a technical blueprint of a system that is intended for others to copy. It contains the essential elements of the system; however, third parties may enhance or modify the design as required....
". Their significance these days is much smaller than it was in the days that such boards, (the KIM-1
KIM-1
The KIM-1, short for Keyboard Input Monitor, was a small 6502-based single-board computer developed and produced by MOS Technology, Inc. and launched in 1976...
being the canonical
Canonical
Canonical is an adjective derived from canon. Canon comes from the greek word κανών kanon, "rule" or "measuring stick" , and is used in various meanings....
example) were the only low cost way to get "hands-on" acquainted with microprocessors..
Features
The most important feature of the microprocessor development board was the ROM based built-in machine language monitor, or "debugger" as it was also sometimes called. Often the name of the board was related to the name of this monitor program, for example the name of the monitor program of the KIM-1 was "Keyboard Input Monitor", because the ROM based software allowed entry of programs without the rows of cumbersome toggle switches that older systems used. The popular 6800 based systems often used a monitor with a name with the word "bug" for "debugger" in it, for example the popular "MIKBUG".Input was normally done with a hexadecimal keyboard, using a machine language monitor program, and the display only consisted of a 7-segment display. Backup storage of written assembler programs was primitive: only a cassette type interface was typically provided, or the serial telex interface was used to read (or punch) a papertape.
Often the board has some kind to expansion connector that brought out all the necessary CPU signals, so that an engineer could build and test an experimental interface or other electronic device.
External interfaces on the bare board were often limited to an RS232 serial port, so a terminal, printer, or teletypewriter could be connected.
List of historical development boards
- 8085AAT a 8085 microprocessor training unit from Paccom
- CDP18S020 evaluation board for the RCARCARCA Corporation, founded as the Radio Corporation of America, was an American electronics company in existence from 1919 to 1986. The RCA trademark is currently owned by the French conglomerate Technicolor SA through RCA Trademark Management S.A., a company owned by Technicolor...
CDP1802 microprocessor - EVK 300 6800 single board from American Microsystems (AMI)
- Explorer/85Explorer/85The Netronics Explorer 85 was a Intel 8085 based computer produced by Netronics R&D Ltd. located in New Milford, Connecticut between 1979 and 1984. Netronics also produced the more well known ELF II computer, and the ill fated Explorer 88 computer....
expandable learning system based on the 8085, by Netronics's research and development ltd. - ITT experimenter used switches and LEDs, and an intel 8080
- JOLT was designed by Raymond M. HoltRay holtRaymond M. Holt was a pioneering computer designer and businessman in Silicon Valley.From 1968-1970, Holt developed the first microprocessor chip set for Garrett AiResearch's Central Air Data Computer for the F-14 Tomcat....
, co-founder of Microcomputer Associates, Incorporated. - KIM-1KIM-1The KIM-1, short for Keyboard Input Monitor, was a small 6502-based single-board computer developed and produced by MOS Technology, Inc. and launched in 1976...
the development board for the MOS TechnologyMOS TechnologyMOS Technology, Inc., also known as CSG , was a semiconductor design and fabrication company based in Norristown, Pennsylvania, in the United States. It is most famous for its 6502 microprocessor, and various designs for Commodore International's range of home computers.-History:MOS Technology, Inc...
/RockwellRockwell- People :* Dick Rockwell, an American comic strip and comic book artist, nephew of Norman Rockwell* Francis W. Rockwell, a United States Congressman from Massachusetts* Francis W...
/SynertekSynertekSynertek, Inc. was an American semiconductor manufacturer founded in 1973. The initial founding group consisted of Bob Schreiner , Dan Floyd, Zvi Grinfas, Jack Balletto, and Gunnar Wetlesen. The manufacturing technology was MOS/LSI...
6502MOS Technology 6502The MOS Technology 6502 is an 8-bit microprocessor that was designed by Chuck Peddle and Bill Mensch for MOS Technology in 1975. When it was introduced, it was the least expensive full-featured microprocessor on the market by a considerable margin, costing less than one-sixth the price of...
microprocessor. The name KIM is short for "keyboard input monitor"- SYM-1SYM-1The SYM-1 was a single board "trainer" computer produced by Synertek circa 1978. Originally called the VIM-1 , that name was changed for legal reasons sometime between April and August 1978....
a slightly improved KIM-1 with better software, more memory, and I/O. Also known as the VIM - AIM-65AIM-65The Rockwell AIM-65 computer was a development computer based on the MOS Technology 6502 microprocessor introduced in 1976. The AIM-65 was essentially an expanded KIM-1 computer. Available software included a monitor with line at a time assembler/disassembler, BASIC interpreter, assembler, Pascal,...
an improved KIM-1 with an alphanumerical LED display, and a built-in printer. - The KIM-1 also lead to some unofficial copies, such as the super-KIM and the JuniorElektor Junior ComputerThe Elektor Junior Computer was a simple 6502 based microprocessor development board published in the 1980s in the Dutch, German and later French, Spanish and British versions of Elektor/Elektuur, in the form of a series of articles, and four books...
from the magazine ElektorElektorElektor is a monthly magazine about all aspects of electronics, first published as "Elektuur" in the Netherlands in 1960, and now published worldwide in many languages including English, German, Dutch, French, Greek, Spanish, Swedish, Portuguese and Italian with distribution in over 50 countries...
, and the MCS Alpha 1
- SYM-1
- LC 80 by RobotronRobotronVEB Kombinat Robotron was the biggest East German electronics manufacturer. It was based in Dresden and employed 68,000 people . It produced personal computers, SM EVM minicomputers, the ESER mainframe computers, several computer peripherals as well as home computers, radios and television...
- MAXBOARD development board for the Motorola 6802.
- MEK6800D2MEK6800D2The MEK6800D2 was a development board for the Motorola 6800 microprocessor, produced by Motorola in 1976. It featured a keyboard with hexadecimal keys and a LED display, but also featured an RS-232 asynchronous serial interface for a Teletype or other terminal...
the official development board for the Motorola 6800Motorola 6800The 6800 was an 8-bit microprocessor designed and first manufactured by Motorola in 1974. The MC6800 microprocessor was part of the M6800 Microcomputer System that also included serial and parallel interface ICs, RAM, ROM and other support chips...
microprocessor. The name of the monitor software was MIKBUG - MicroChroma 68 color graphics kit. Developed by Motorola to demonstrate their new 6847 video display processor. The monitor software was called TVBUG
- Motorola EXORcisor development system (rack based) for the Motorola 6809Motorola 6809The Motorola 6809 is an 8-bit microprocessor CPU from Motorola, designed by Terry Ritter and Joel Boney and introduced 1978...
- Microprofessor IMicroprofessor IThe Micro-Professor MPF-I, introduced in 1981 by Multitech , was the first branded computer product from Multitech and probably one of the world's longest selling computers...
(MPF-1) Z80 development and training system by AcerAcer (company)Acer Incorporated is a multinational information technology and electronics corporation headquartered in Xizhi, New Taipei City, Taiwan. Acer's products include desktop and laptop PCs, tablet computers, servers, storage devices, displays, smartphones and peripherals... - MST-80B 8080 training system by the Lawrence Livermore National LaboratoryLawrence Livermore National LaboratoryThe Lawrence Livermore National Laboratory , just outside Livermore, California, is a Federally Funded Research and Development Center founded by the University of California in 1952...
- NS introkit by National SemiconductorNational SemiconductorNational Semiconductor was an American semiconductor manufacturer, that specialized in analog devices and subsystems,formerly headquartered in Santa Clara, California, USA. The products of National Semiconductor included power management circuits, display drivers, audio and operational amplifiers,...
featuring the SC/MP, the predecessor to the Sinclair MK14MK14The Microcomputer Kit 14, or MK14 was a computer kit sold by Science of Cambridge of the United Kingdom, first introduced in 1977 for UK£39.95. The MK14 eventually sold over 50,000 units. It used a National Semiconductor SC/MP CPU , 256 bytes of random access memory which was directly expandable... - NRI microcomputer, a system developed to teach computer courses by McGraw-HillMcGraw-HillThe McGraw-Hill Companies, Inc., is a publicly traded corporation headquartered in Rockefeller Center in New York City. Its primary areas of business are financial, education, publishing, broadcasting, and business services...
and the National Radio InstituteI (NRI) - MK14MK14The Microcomputer Kit 14, or MK14 was a computer kit sold by Science of Cambridge of the United Kingdom, first introduced in 1977 for UK£39.95. The MK14 eventually sold over 50,000 units. It used a National Semiconductor SC/MP CPU , 256 bytes of random access memory which was directly expandable...
Trainings system for the SC/MP microprocessor from Sinclair Research Ltd. - SDK-80 Intels development board for their 8080Intel 8080The Intel 8080 was the second 8-bit microprocessor designed and manufactured by Intel and was released in April 1974. It was an extended and enhanced variant of the earlier 8008 design, although without binary compatibility...
microprocessor - SDK-51 Intels development board for their Intel MCS-51Intel MCS-51The Intel MCS-51 is a Harvard architecture, single chip microcontroller series which was developed by Intel in 1980 for use in embedded systems. Intel's original versions were popular in the 1980s and early 1990s. While Intel no longer manufactures the MCS-51, binary compatible derivatives remain...
- SDK-85 Intels development board for their 8085Intel 8085The Intel 8085 is an 8-bit microprocessor introduced by Intel in 1977. It was binary-compatible with the more-famous Intel 8080 but required less supporting hardware, thus allowing simpler and less expensive microcomputer systems to be built....
microprocessor - SDK-86 Intels development board for their 8086Intel 8086The 8086 is a 16-bit microprocessor chip designed by Intel between early 1976 and mid-1978, when it was released. The 8086 gave rise to the x86 architecture of Intel's future processors...
microprocessor - Siemens Microset-8080 boxed system based on a 8080.
- SigneticsSigneticsSignetics, once a major player in semiconductor manufacturing, made a variety of devices which included integrated circuits, bipolar and MOS, the Dolby circuit, logic, memory and analog circuits. They developed microprocessors like the 2650, the bipolar 8X300 and had licensed Motorola 68000...
Instructor 50 based on the Signetics 2650Signetics 2650The Signetics 2650, was a very early 8-bit microprocessor. According to Adam Osborne's classic book An Introduction to Microprocessors Vol 2: Some Real Products, it was "the most minicomputer-like" of the microprocessors available at the time....
. - RCA Cosmac Super Elf by RCARCARCA Corporation, founded as the Radio Corporation of America, was an American electronics company in existence from 1919 to 1986. The RCA trademark is currently owned by the French conglomerate Technicolor SA through RCA Trademark Management S.A., a company owned by Technicolor...
. a 1802 learning system with an RCA 1861 Video Display ControllerVideo Display ControllerA Video Display Controller or VDC is an integrated circuit which is the main component in a video signal generator, a device responsible for the production of a TV video signal in a computing or game system...
. - TK-80 the development board for NECNEC, a Japanese multinational IT company, has its headquarters in Minato, Tokyo, Japan. NEC, part of the Sumitomo Group, provides information technology and network solutions to business enterprises, communications services providers and government....
's clone of Intel's i8080, the μPD 8080A - TM 990/100M evaluation board for the Texas InstrumentsTexas InstrumentsTexas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
TMS9900 - TM 990/180M evaluation board for the Texas InstrumentsTexas InstrumentsTexas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
TMS9800 - XPO-1 Texas Instruments development system for the PPS-4/1 line of microcontrollers
See also
- Embedded systemEmbedded systemAn embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...
- Intel System Development KitIntel System Development KitEach time Intel launched a new microprocessor, they provided simultaneously a System Development Kit allowing computer company engineers as well as university students to introduce them to the new processor concepts and features.-Intel MIC-8:...
- Single-board computerSingle-board computerA single-board computer is a complete computer built on a single circuit board, with microprocessor, memory, input/output and other features required of a functional computer. Unlike a typical personal computer, an SBC may not include slots into which accessory cards may be plugged...
- Single-board microcontrollerSingle-board microcontrollerA single-board microcontroller is a microcontroller built onto a single printed circuit board. This board provides all of the circuitry necessary for a useful control task: microprocessor, I/O circuits, clock generator, RAM, stored program memory and any support ICs necessary...