The
Kansas City Standard (
KCS), or Byte
standard, is a digital data format for audio cassette drives. Byte magazine sponsored a symposium in November 1975 in
Kansas City, MissouriKansas City is the largest city in the U.S. state of Missouri. It encompasses in parts of Jackson, Clay, Cass, and Platte counties. It is one of two county seats of Jackson County, the other being Independence, just to the city's east...
to develop a standard for storage of digital
(micro)A microcomputer is a computer with a microprocessor as its central processing unit. Another general characteristic of these computers is that they occupy physically small amounts of space when compared to mainframe and minicomputers...
computerA computer is a machine that manipulates data according to a set of instructions.Although mechanical examples of computers have existed through much of recorded human history, the first electronic computers were developed in the mid-20th century . These were the size of a large room, consuming as...
data on inexpensive consumer quality
cassettesThe Compact Cassette, often referred to as audio cassette, cassette tape, cassette, or simply tape, is a magnetic tape sound recording format. Although originally designed for dictation, improvements in fidelity led the Compact Cassette to supplant reel-to-reel tape recording in most...
, at a time when
floppy diskA floppy disk is a data storage medium that is composed of a disk of thin, flexible magnetic storage medium encased in a square or rectangular plastic shell. Floppy disks are read and written by a floppy disk drive or FDD, the initials of which should not be confused with "fixed disk drive," which...
drives cost over $1000 USD each.
The two-day meeting was attended by 18 people who settled on a system based on
Don LancasterDonald 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.
The
Kansas City Standard (
KCS), or Byte
standard, is a digital data format for audio cassette drives. Byte magazine sponsored a symposium in November 1975 in
Kansas City, MissouriKansas City is the largest city in the U.S. state of Missouri. It encompasses in parts of Jackson, Clay, Cass, and Platte counties. It is one of two county seats of Jackson County, the other being Independence, just to the city's east...
to develop a standard for storage of digital
(micro)A microcomputer is a computer with a microprocessor as its central processing unit. Another general characteristic of these computers is that they occupy physically small amounts of space when compared to mainframe and minicomputers...
computerA computer is a machine that manipulates data according to a set of instructions.Although mechanical examples of computers have existed through much of recorded human history, the first electronic computers were developed in the mid-20th century . These were the size of a large room, consuming as...
data on inexpensive consumer quality
cassettesThe Compact Cassette, often referred to as audio cassette, cassette tape, cassette, or simply tape, is a magnetic tape sound recording format. Although originally designed for dictation, improvements in fidelity led the Compact Cassette to supplant reel-to-reel tape recording in most...
, at a time when
floppy diskA floppy disk is a data storage medium that is composed of a disk of thin, flexible magnetic storage medium encased in a square or rectangular plastic shell. Floppy disks are read and written by a floppy disk drive or FDD, the initials of which should not be confused with "fixed disk drive," which...
drives cost over $1000 USD each.
The two-day meeting was attended by 18 people who settled on a system based on
Don LancasterDonald 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 FelsensteinLee Felsenstein is a computer engineer who played a central role in the development of the personal computer. He was one of the original members of the Homebrew Computer Club and the designer of the Osborne 1, the first mass-produced portable computer.Before the Osborne, Lee designed the Intel...
(
Processor TechnologyProcessor Technology Corporation was a microcomputer company founded by Bob Marsh in April 1975.-History:Bob Marsh, Lee Felsenstein and Gordon French started designing the Sol-20 Terminal Computer in June 1975. The SOL-20 utilized the Intel 8080 8-bit microprocessor chip, running at 2 MHz...
) and Harold Mauch (Percom Data Company) wrote the standard.
A cassette interface is similar to a modem connected to a
serial portIn telecommunication and computer science, serial communication is the process of sending data one bit at one time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent together, on a link with several parallel channels...
. The 1s and 0s from the serial port are converted audio tones, this is known as audio frequency-shift keying (AFSK). A '0' bit is represented as four cycles of a 1200
HzThe hertz is a unit of frequency. It is defined as the number of complete cycles per second. It is the basic unit of frequency in the International System of Units , and is used worldwide in both general-purpose and scientific contexts...
sine waveThe sine wave or sinusoid is a function that occurs often in mathematics, music, physics, signal processing, audition, electrical engineering, and many other fields...
, and a '1' bit as eight cycles of 2400 Hz. This gives a data rate of 300
baudIn 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 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
BASICIn computer programming, BASIC is a family of high-level programming languages. The original BASIC was designed in 1964 by John George Kemeny and Thomas Eugene Kurtz at Dartmouth in New Hampshire, USA to provide computer access to non-science students...
program took five minutes to load.) Most audio
cassetteThe Compact Cassette, often referred to as audio cassette, cassette tape, cassette, or simply tape, is a magnetic tape sound recording format. Although originally designed for dictation, improvements in fidelity led the Compact Cassette to supplant reel-to-reel tape recording in most...
circuits would support higher speeds.
Processor TechnologyProcessor Technology Corporation was a microcomputer company founded by Bob Marsh in April 1975.-History:Bob Marsh, Lee Felsenstein and Gordon French started designing the Sol-20 Terminal Computer in June 1975. The SOL-20 utilized the Intel 8080 8-bit microprocessor chip, running at 2 MHz...
developed the popular CUTS
(Computer
Users
' Tape
Standard) which worked at either 300 or 1200 baud. Process Technology developed the S-100 bus CUTS Tape I/O interface board. This board offered Kansas City Standard to any S-100 system. Processor Technology sold many programs on cassette tape.
CUTS format on one side, and Kansas City Standard on the other side.
Participants of the Kansas City symposium
- Ray Borril
Ray Borril 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 first computer...
, Bloomington IN
- Hal Chamberlin, The Computer Hobbyist, Raleigh NC
- Richard Smith, The Computer Hobbyist, Raleigh NC
- Tom Durston, MITS
Micro 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 Gates
William Henry "Bill" Gates III is an American business magnate, philanthropist, and chairman of Microsoft, the software company he founded with Paul Allen.He is ranked consistently one of the world's wealthiest people...
, MITSMicro 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 Roberts, MITS
Micro 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, MITS
Micro 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 Felsenstein
Lee Felsenstein is a computer engineer who played a central role in the development of the personal computer. He was one of the original members of the Homebrew Computer Club and the designer of the Osborne 1, the first mass-produced portable computer.Before the Osborne, Lee designed the Intel...
, LGC Engineering / Processor TechnologyProcessor Technology Corporation was a microcomputer company founded by Bob Marsh in April 1975.-History:Bob Marsh, Lee Felsenstein and Gordon French started designing the Sol-20 Terminal Computer in June 1975. The SOL-20 utilized the Intel 8080 8-bit microprocessor chip, running at 2 MHz...
, Berkeley CA
- Les Solomon, Popular Electronics
Popular Electronics was an American magazine started by Ziff-Davis Publishing in October 1954 for hobbyist and experimenters in electronics. 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 Technology
Processor Technology Corporation was a microcomputer company founded by Bob Marsh in April 1975.-History:Bob Marsh, Lee Felsenstein and Gordon French started designing the Sol-20 Terminal Computer in June 1975. The SOL-20 utilized the Intel 8080 8-bit microprocessor chip, running at 2 MHz...
, Berkeley CA
- Joe Frappier, Mikra-D, Bellingham MA
- Gary Kay, Southwest Technical Products Corp
The 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 Electronics
Bill 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
In August 1976 at the Personal Computing show in Atlantic City, Bob Marsh of Processor Technology approached Bob Jones, the publisher of
Interface Age magazine, about pressing software onto vinyl records. Processor Technology provided an
8080The Intel 8080 was an early microprocessor designed and manufactured by Intel. The 8-bit microprocessor was released in April 1974 running at 2 MHz , and is generally considered to be the first truly usable microprocessor...
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
6800The 6800 is an 8-bit microprocessor produced by Motorola and released shortly after the Intel 8080 in late 1974. It had 78 instructions, including the famous, undocumented Halt and Catch Fire bus test instruction...
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 sheetsThe 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 original 300 baudIn 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 a recorded data as "marks" (one) and "spaces" (zero). A mark bit consisted of eight cycles at a frequency of 2400
HzHz or hz may mean:*Herero language *Hertz, unit of frequency*Hamilton Zoo, New Zealand...
, while a space bit consisted of four cycles at a frequency of 1200 Hz. A
wordA word is the smallest free form in a language, in contrast to a morpheme, which is the smallest unit of meaning. A word may consist of only one morpheme , but a single morpheme may not be able to exist as a free form A word is the smallest free form (an item that may be uttered in isolation with...
, usually one
byteA byte is a unit of information storage representing the smallest addressable element for a given computer architecture. It often designates a sequence of bits whose length is determined by the architecture...
(8 bits) in length, was recorded in little endian order, i.e. least significant bit first. 7-bit words were followed by a
parity bitA 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 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...
and
Acorn 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....
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
blocksIn 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-100The S-100 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 . The S-100 bus was the first industry standard bus for the microcomputer industry...
based):
- Compukit UK101
- Lucas Nascom
The 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 for storing 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)
- MITS
Micro 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 8800The MITS Altair 8800 was a microcomputer design from 1975, based on the Intel 8080 CPU and sold as a mail-order kit through advertisements in Popular Electronics, Radio-Electronics and other hobbyist magazines. The designers intended to sell only a few hundred to hobbyists, and were surprised when...
- MOS
MOS 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-1The KIM-1, short for Keyboard Input Monitor, was a small 6502-based microcomputer kit developed and produced by MOS Technology, Inc. and launched in 1975...
- Motorola
Motorola, Inc. is an American, multinational, Fortune 100, telecommunications company based in Schaumburg, Illinois. It is a manufacturer of wireless telephone handsets, and also designs and sells wireless network infrastructure equipment such as cellular transmission base stations and signal...
MEK D1 6800 board
- Ohio Scientific
Ohio 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 Tech
Processor Technology Corporation was a microcomputer company founded by Bob Marsh in April 1975.-History:Bob Marsh, Lee Felsenstein and Gordon French started designing the Sol-20 Terminal Computer in June 1975. The SOL-20 utilized the Intel 8080 8-bit microprocessor chip, running at 2 MHz...
SOL-20 Terminal Computer
- Processor Tech
Processor Technology Corporation was a microcomputer company founded by Bob Marsh in April 1975.-History:Bob Marsh, Lee Felsenstein and Gordon French started designing the Sol-20 Terminal Computer in June 1975. The SOL-20 utilized the Intel 8080 8-bit microprocessor chip, running at 2 MHz...
CUTSCuts 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
- SWTPC
The U.S. company SWTPC started in 1964 as DEMCO . It was incorporated in 1967 as Southwest Technical Products Corporation of San Antonio, Texas...
's 6800The 6800 is an 8-bit microprocessor produced by Motorola and released shortly after the Intel 8080 in late 1974. It had 78 instructions, including the famous, undocumented Halt and Catch Fire bus test instruction...
-based computers
- Tangerine MICROTAN 65
The 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)
Home/personal computers:
- ABC 80
- Acorn Computers Ltd
- Acorn Atom
The Acorn Atom was a home computer made by Acorn Computers Ltd from 1980 to 1981 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 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...
(300 and 1200 baud variations)
- 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....
(1200 baud only)
- Dick Smith Super-80
The 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)
- Heathkit
Heathkits 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, and the influential Heath H-8, H-89, and H-11 hobbyist computers, which were sold in kit form...
- Heathkit H8
Heathkit'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 Z89
The 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)
- MicroBee Systems
- MicroBee
MicroBee 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)
Programmable calculators:
- Casio
is a multinational electronic devices manufacturing company founded in 1946, with its headquarters in Shibuya, Tokyo, Japan. Casio is best known for its calculators, audio equipment, PDAs, cameras, musical instruments, and watches...
- FX-502P series
The 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-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 series
The 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-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-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-603P
The 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-850PThe Casio FX-850P is a scientific calculator from the 1990s.- Specifications :* 2 lines with 32 5×7 characters LCD** * 8 KB RAM * CPU: VLSI at 1,228MHz...
with 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)
See also
- UEF
UEF is a compressed, chunked file format for the storage of audio tapes, ROMs, floppy disks and machine state snapshots for the 8-bit range of computers manufactured by Acorn Computers Ltd...
- a popular file format for archiving Kansas City standard audio
External links