Kansas City standard
Encyclopedia
Kansas City, Missouri
Kansas City, Missouri is the largest city in the U.S. state of Missouri and is the anchor city of the Kansas City Metropolitan Area, the second largest metropolitan area in Missouri. It encompasses in parts of Jackson, Clay, Cass, and Platte counties...
to develop a standard for storage of digital (micro)
Microcomputer
A microcomputer is a computer with a microprocessor as its central processing unit. They are physically small compared to mainframe and minicomputers...
computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
data on inexpensive consumer quality cassettes
Compact Cassette
The Compact Cassette, often referred to as audio cassette, cassette tape, cassette, or simply tape, is a magnetic tape sound recording format. It was designed originally for dictation, but improvements in fidelity led the Compact Cassette to supplant the Stereo 8-track cartridge and reel-to-reel...
, at a time when floppy disk
Floppy disk
A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles...
drives cost over $1000 USD each.
The two-day meeting was attended by 18 people who settled on a system based on Don Lancaster
Don Lancaster
Donald E. Lancaster is a prolific author, inventor, and microcomputer pioneer best known for his magazine columns. He is also known for his "TV Typewriter" dumb terminal project, his book on technical entrepreneurship The Incredible Secret Money Machine, and his work on and advocacy of early...
's design, published in Byte magazine's first issue. After the meeting, Lee Felsenstein
Lee Felsenstein
Lee Felsenstein is an American computer engineer who played a central role in the development of the personal computer...
(Processor Technology
Processor Technology
Processor Technology Corporation was a microcomputer company founded by Bob Marsh and Gary Ingram in April 1975. Its best known product is the Sol-20 computer.-History:...
) and Harold Mauch (Percom Data Company) wrote the standard.
A cassette interface is similar to a modem connected to a serial port
Serial communications
In telecommunication and computer science, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels...
. The 1s and 0s from the serial port are converted to audio tones using audio frequency-shift keying (AFSK). A '0' bit is represented as four cycles of a 1200 Hz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
sine wave
Sine wave
The sine wave or sinusoid is a mathematical function that describes a smooth repetitive oscillation. It occurs often in pure mathematics, as well as physics, signal processing, electrical engineering and many other fields...
, and a '1' bit as eight cycles of 2400 Hz. This gives a data rate of 300 baud
Baud
In telecommunications and electronics, baud is synonymous to symbols per second or pulses per second. It is the unit of symbol rate, also known as baud rate or modulation rate; the number of distinct symbol changes made to the transmission medium per second in a digitally modulated signal or a...
. Each frame starts with one start bit (a '0') followed by eight data bits (least significant bit first) followed by two stop bits ('1's). So each frame is 11 bits, for a data rate of 27 3/11ths bytes per second.
The February 1976 issue of Byte had a report on the symposium and the March issue featured two hardware examples by Don Lancaster and Harold Mauch. The 300 baud rate was reliable but slow. (The typical 8-kilobyte BASIC
BASIC
BASIC is a family of general-purpose, high-level programming languages whose design philosophy emphasizes ease of use - the name is an acronym from Beginner's All-purpose Symbolic Instruction Code....
program took five minutes to load.) Most audio cassette
Compact Cassette
The Compact Cassette, often referred to as audio cassette, cassette tape, cassette, or simply tape, is a magnetic tape sound recording format. It was designed originally for dictation, but improvements in fidelity led the Compact Cassette to supplant the Stereo 8-track cartridge and reel-to-reel...
circuits would support higher speeds.
Processor Technology
Processor Technology
Processor Technology Corporation was a microcomputer company founded by Bob Marsh and Gary Ingram in April 1975. Its best known product is the Sol-20 computer.-History:...
developed the popular CUTS (Computer Users
Participants of the Kansas City symposium
- Ray BorrillRay BorrillBoyd Raymond 'Ray' Borrill was founder of The Data Domain, a retail computer store in Bloomington, Indiana, and vice-president of itty bitty machine company retail computer store. 1977-1980, located in Evanston, Illinois. These stores have their place in computer history as they are two of the...
, Bloomington IN - Hal Chamberlin, The Computer Hobbyist, Raleigh NC
- Richard Smith, The Computer Hobbyist, Raleigh NC
- Tom Durston, MITSMicro Instrumentation and Telemetry SystemsMicro Instrumentation and Telemetry Systems was an American electronics company founded in Albuquerque, New Mexico that began manufacturing electronic calculators in 1971 and personal computers in 1975. Ed Roberts and Forrest Mims founded MITS in December 1969 to produce miniaturized telemetry...
, Albuquerque NM - Bill GatesBill GatesWilliam Henry "Bill" Gates III is an American business magnate, investor, philanthropist, and author. Gates is the former CEO and current chairman of Microsoft, the software company he founded with Paul Allen...
, MITSMicro Instrumentation and Telemetry SystemsMicro Instrumentation and Telemetry Systems was an American electronics company founded in Albuquerque, New Mexico that began manufacturing electronic calculators in 1971 and personal computers in 1975. Ed Roberts and Forrest Mims founded MITS in December 1969 to produce miniaturized telemetry...
, Albuquerque NM - Ed RobertsEd Roberts (computers)Henry Edward "Ed" Roberts was an American engineer, entrepreneur and medical doctor who designed the first commercially successful personal computer in 1975. He is most often known as "the father of the personal computer"...
, MITSMicro Instrumentation and Telemetry SystemsMicro Instrumentation and Telemetry Systems was an American electronics company founded in Albuquerque, New Mexico that began manufacturing electronic calculators in 1971 and personal computers in 1975. Ed Roberts and Forrest Mims founded MITS in December 1969 to produce miniaturized telemetry...
, Albuquerque NM - Bob Zaller, MITSMicro Instrumentation and Telemetry SystemsMicro Instrumentation and Telemetry Systems was an American electronics company founded in Albuquerque, New Mexico that began manufacturing electronic calculators in 1971 and personal computers in 1975. Ed Roberts and Forrest Mims founded MITS in December 1969 to produce miniaturized telemetry...
, Albuquerque NM - Lee FelsensteinLee FelsensteinLee Felsenstein is an American computer engineer who played a central role in the development of the personal computer...
, LGC Engineering / Processor TechnologyProcessor TechnologyProcessor Technology Corporation was a microcomputer company founded by Bob Marsh and Gary Ingram in April 1975. Its best known product is the Sol-20 computer.-History:...
, Berkeley CA - Les Solomon, Popular ElectronicsPopular ElectronicsPopular Electronics was an American magazine started by Ziff-Davis Publishing in October 1954 for electronics hobbyists and experimenters. It soon became the "World's Largest-Selling Electronics Magazine". The circulation was 240,151 in April 1957 and 400,000 by 1963. Ziff-Davis published Popular...
Magazine, New York NY - Bob Marsh, Processor TechnologyProcessor TechnologyProcessor Technology Corporation was a microcomputer company founded by Bob Marsh and Gary Ingram in April 1975. Its best known product is the Sol-20 computer.-History:...
, Berkeley CA - Joe Frappier, Mikra-D, Bellingham MA
- Gary Kay, Southwest Technical Products CorpSWTPCThe U.S. company SWTPC started in 1964 as DEMCO . It was incorporated in 1967 as Southwest Technical Products Corporation of San Antonio, Texas...
, San Antonio TX - Harold A Mauch, Pronetics/Percom Data, Garland TX
- Bob Nelson, PCM, San Ramon CA
- George Perrine, HAL Communications Corp, Urbana IL
- Paul Tucker, HAL Communications Corp, Urbana IL
- Michael Stolowitz, Godbout ElectronicsBill GodboutBill Godbout was an early computer pioneer and entrepreneur known for manufacturing and selling computer equipment, parts and Electronic kits in Silicon Valley, before the time of the Apple II....
, Oakland Airport CA - Mike Wise, Sphere, Bountiful UT
Floppy-ROM
Intel 8080
The 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...
program to be recorded. This test record did not work and they were unable to devote more time to the effort.
Daniel Meyer and Gary Kay of Southwest Technical Products arranged for Robert Uiterwyk to provide his 4K BASIC interpreter program for the 6800
Motorola 6800
The 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 idea was to record the program on audio tape in the "Kansas City Standard" format then make a master record from the tape. Eva-Tone made "sound sheets
Flexi disc
The flexi disc is a phonograph record made of a thin, flexible vinyl sheet with a molded-in spiral stylus groove, and is designed to be playable on a normal phonograph turntable...
" on thin vinyl that would hold one song. These were inexpensive and could be bound in a magazine.
Bill Turner and Bill Blomgren of MicroComputerSystems Inc. worked with EVA-TONE and developed a successful process. The intermediate stage of recording to tape produced dropouts so a SWTPC AC-30 cassette interface was connected directly to the record cutting equipment.
The May 1977 issue of Interface Age contained the first "Floppy-ROM", a 33⅓ RPM record with about 6 minutes of "Kansas City Standard" audio.
The September 1978 Floppy-Rom Number 5:.
Side 1 Apple Basic "the automated dress pattern".
Side 2 IAPS format "A program for writing letters".
The original 300 baudBaudIn telecommunications and electronics, baud is synonymous to symbols per second or pulses per second. It is the unit of symbol rate, also known as baud rate or modulation rate; the number of distinct symbol changes made to the transmission medium per second in a digitally modulated signal or a...
standard
The original standard recorded data as "marks" (one) and "spaces" (zero). A mark bit consisted of eight cycles at a frequency of 2400 HzHertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
, while a space bit consisted of four cycles at a frequency of 1200 Hz. A word
Word
In language, a word is the smallest free form that may be uttered in isolation with semantic or pragmatic content . This contrasts with a morpheme, which is the smallest unit of meaning but will not necessarily stand on its own...
, usually one 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...
(8 bits) in length, was recorded in little endian order, i.e. least significant bit first. 7-bit words were followed by a parity bit
Parity bit
A parity bit is a bit that is added to ensure that the number of bits with the value one in a set of bits is even or odd. Parity bits are used as the simplest form of error detecting code....
.
1200 baud variation
Acorn Computers Ltd implemented a 1200 baud variation of CUTS in their BBC MicroBBC Micro
The BBC Microcomputer System, or BBC Micro, was a series of microcomputers and associated peripherals designed and built by Acorn Computers for the BBC Computer Literacy Project, operated by the British Broadcasting Corporation...
and Acorn Electron
Acorn Electron
The Acorn Electron is a budget version of the BBC Micro educational/home computer made by Acorn Computers Ltd. It has 32 kilobytes of RAM, and its ROM includes BBC BASIC along with its operating system....
microcomputers, which reduced a '0' bit to one cycle of a 1200 Hz sine wave and a '1' bit to two cycles of a 2400 Hz wave. Standard encoding includes a '0' start bit and '1' stop bit around every 8 bit piece of information, giving an effective data rate of 960 bits per second.
Also, these machines recorded data in 256-byte blocks
Block (data storage)
In computing , a block is a sequence of bytes or bits, having a nominal length . Data thus structured are said to be blocked. The process of putting data into blocks is called blocking. Blocking is used to facilitate the handling of the data-stream by the computer program receiving the data...
interspersed with gaps of carrier tone, each block carrying a sequence number, so that it was possible to rewind the tape and resume at the proper block when a read error occurred.
Computers using the Kansas City standard
Early microcomputers (several of them S-100S-100 bus
The S-100 bus or Altair bus, IEEE696-1983 , was an early computer bus designed in 1974 as a part of the Altair 8800, generally considered today to be the first personal computer...
based):
- Compukit UK101
- Exidy SorcererExidy SorcererThe Sorcerer was one of the early home computer systems, released in 1978 by the videogame company, Exidy. It was comparatively advanced when released, especially when compared to the contemporary more commercially-orientated Commodore PET and TRS-80, but due to a number of problems including a...
Optional S-100 expansion bus, standard 300 bit/s mode and a 1200 baud variant by default. - Lucas NascomNascomThe Nascom 1 and 2 were single-board computer kits issued in 1977 and 1979, respectively, based on the Zilog Z80 and including a keyboard and video interface, a serial port that could be used to store data on a tape cassette using the Kansas City standard, and two 8-bit parallel ports...
1, 2 (which also supported a 1200 bit/s variant, see below) - MITSMicro Instrumentation and Telemetry SystemsMicro Instrumentation and Telemetry Systems was an American electronics company founded in Albuquerque, New Mexico that began manufacturing electronic calculators in 1971 and personal computers in 1975. Ed Roberts and Forrest Mims founded MITS in December 1969 to produce miniaturized telemetry...
Altair 8800Altair 8800The MITS Altair 8800 was a microcomputer design from 1975 based on the Intel 8080 CPU and sold by mail order through advertisements in Popular Electronics, Radio-Electronics and other hobbyist magazines. The designers hoped to sell only a few hundred build-it-yourself kits to hobbyists, and were... - MOSMOS 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...
/CBM 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... - MotorolaMotorolaMotorola, Inc. was an American multinational telecommunications company based in Schaumburg, Illinois, which was eventually divided into two independent public companies, Motorola Mobility and Motorola Solutions on January 4, 2011, after losing $4.3 billion from 2007 to 2009...
MEK D1 6800 board - Ohio ScientificOhio ScientificOhio Scientific Inc. was a United States computer company that built and marketed computers from the late 1970s to the early 1980s...
C1P/Superboard II - Processor TechProcessor TechnologyProcessor Technology Corporation was a microcomputer company founded by Bob Marsh and Gary Ingram in April 1975. Its best known product is the Sol-20 computer.-History:...
SOL-20 Terminal Computer - Processor TechProcessor TechnologyProcessor Technology Corporation was a microcomputer company founded by Bob Marsh and Gary Ingram in April 1975. Its best known product is the Sol-20 computer.-History:...
CUTSCutsCuts is an American sitcom that aired on the UPN network from February 14, 2005, to May 11, 2006, and is a spin-off of another UPN series, One on One...
S-100 bus Tape I/O interface board - SWTPCSWTPCThe U.S. company SWTPC started in 1964 as DEMCO . It was incorporated in 1967 as Southwest Technical Products Corporation of San Antonio, Texas...
's 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...
-based computers - Tangerine MICROTAN 65Tangerine MICROTAN 65The Tangerine Microtan 65 was a 6502 based single board microcomputer, first sold in 1979, which could be expanded into, what was for its day, a comprehensive and powerful system. The design became the basis for what later became the ORIC, ATMOS and later computers, which had similar keyboard...
(300 baud CUTS - faster 2400 non-CUTS format also available) - Eltec (German Company) Eurocom 1
Home/personal computers:
- ABC 80
- Acorn Computers Ltd
- Acorn AtomAcorn AtomThe Acorn Atom was a home computer made by Acorn Computers Ltd from 1980 to 1982 when it was replaced by the BBC Micro and later the Acorn Electron....
(300 baud standard / 1200 baud with the "fast cos" program from utility pack 1) - BBC MicroBBC MicroThe BBC Microcomputer System, or BBC Micro, was a series of microcomputers and associated peripherals designed and built by Acorn Computers for the BBC Computer Literacy Project, operated by the British Broadcasting Corporation...
(300 and 1200 baud variations) - Acorn ElectronAcorn ElectronThe Acorn Electron is a budget version of the BBC Micro educational/home computer made by Acorn Computers Ltd. It has 32 kilobytes of RAM, and its ROM includes BBC BASIC along with its operating system....
(1200 baud only)
- Acorn Atom
- Dick Smith Super-80Dick Smith Super-80 ComputerThe Dick Smith Super-80 was a Zilog Z80 based kit computer developed as a joint venture between Electronics Australia magazine and Dick Smith Electronics...
(300 baud only) - 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...
Magazine National SC/MP Project - HeathkitHeathkitHeathkits were products of the Heath Company, Benton Harbor, Michigan. Their products included electronic test equipment, high fidelity home audio equipment, television receivers, amateur radio equipment, electronic ignition conversion modules for early model cars with point style ignitions, and...
- Heathkit H8Heathkit H8Heathkit's H8 was an Intel 8080-based microcomputer sold in kit form starting in 1977. The H8 was similar to the S-100 bus computers of the era, and like those machines was often used with the CP/M operating system on floppy disk...
(300 and 1200 baud) - Heathkit H89 - also sold as the Zenith Z89Zenith Z89The Z-89 was a personal computer produced by Zenith Data Systems in the early 1980s. It was based on the Zilog Z80 microprocessor and ran the HDOS and CP/M operating systems...
(300 and 1200 baud)
- Heathkit H8
- MicroBee Systems
- MicroBeeMicroBeeMicroBee was a series of home computers by Applied Technology, later known as MicroBee Systems.The original MicroBee computer was designed in Australia by a team including Owen Hill and Matthew Starr...
(300 and 1200 baud)
- MicroBee
- Sega SC-3000 A slightly different 600 baud variant
Programmable calculators:
- CasioCasiois a multinational electronic devices manufacturing company founded in 1946, with its headquarters in Shibuya, Tokyo, Japan. Casio is best known for its electronic products, such as calculators, audio equipment, PDAs, cameras, musical instruments, and watches...
- FX-502P seriesCasio FX-502P seriesThe FX-501P and FX-502P were programmable calculators, manufactured by CASIO from 1978. They were the predecessors of the Casio FX-601P and Casio FX-602P.-Arithmetic:The FX-502P series use the algebraic logic as was state of the art at the time....
with FA-1Casio FA-1The FA-1 Interface was used the FX-502P and FX-602P series of programmable calculator to store programs and data register to Compact Cassette.-External links:* on shows the FA-1 interface....
interface (300 baud) - FX-602P seriesCasio FX-602P seriesThe FX-601P and FX-602P were programmable calculators, manufactured by CASIO from 1981. It was the successor model to the Casio FX-502P series and was itself succeeded in 1990 by the Casio FX-603P.-Display:...
and FX-702PCasio FX-702PThe FX-702P is a Pocket Computer, manufactured by Casio from 1981 to 1984.-Display:The FX-702P features a single line dot matrix liquid crystal display with 20 characters. A 10-digit mantissa is displayed however internal calculations use a 12-digit mantissa.-Programming:The programming model...
with FA-2Casio FA-2The FA-2 Interface was used the FX-602P series of programmable calculator and the FX-702P Pocket Computer to store programs and data register to Compact Cassette. When compared with its predecessor the Casio FA-1 the FA-2 featured an additional tape control output and connector for the Casio FP-10...
interface (300 baud) - Casio FX-603PCasio FX-603PThe FX-603P was a programmable calculator, manufactured by CASIO from 1990. It was the successor model to the Casio FX-602P.-Display:The FX-603P featured a two line dot matrix display with 16 characters each as main display...
and Casio FX-850PCasio FX-850PThe Casio FX-850P is a scientific calculator introduced in 1987 and sold until 1992.- Specifications :* 2 lines with 32 5×7 characters LCD** * 8 KB RAM...
with FA-6Casio FA-6The FA-6 Interface was used with the Casio FX-603P, Casio FX-840P, Casio FX-841P, Casio FX-850P, Casio FX-860P, Casio FX-860Pvc, Casio FX-870P, Casio FX-880P, Casio FX-890P, Casio VX-1, Casio VX-2, Casio VX-3, Casio VX-4, Casio Z-1 and Casio Z-1GR programmable calculator and Pocket Computers.It...
interface (300 and 1200 baud) - PB-700 (with FA-11 interface)
- FX-502P series
Other devices:
- Casio PT-50CasiotoneCasiotone refers to a series of home electronic keyboards released by Casio Computer Co. in the early 1980s.These first keyboards used a sound synthesis technique known as Vowel-Consonant synthesis to approximate the sounds of other instruments...
electronic keyboardElectronic keyboardAn electronic keyboard is an electronic or digital keyboard instrument.The major components of a typical modern electronic keyboard are:...
with TA-1 tape interface module.
See also
- UEFUEF (file format)Unified Emulator Format is a container format for the compressed storage of audio tapes, ROMs, floppy disks and machine state snapshots for the 8-bit range of computers manufactured by Acorn Computers...
- a popular file format for archiving Kansas City standard audio - BASICODE - a common basic platform using the 1200 baud KCS
External links
- The original Byte Magazine article
- Sound sample of stored KCS file
- SWTPC.com's article on the AC-30 cassette interface
- KCS decoding software for MS-DOS
- Percom Data CIS-30 Cassette Interface Brochure
- MakeUEF - KCS audio to UEF file conversion software
- FreeUEF - standalone UEF to KCS audio conversion software
- UEFReader - UEF to KCS audio conversion plugin for Java Sound applications
- Perl script to decode a wav file in KCS format to a text file using Fast Fourier Transforms