SWTPC
Encyclopedia
The U.S.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 company SWTPC started in 1964 as DEMCO (Daniel E. Meyer Company). It was incorporated in 1967 as Southwest Technical Products Corporation of San Antonio, Texas
San Antonio, Texas
San Antonio is the seventh-largest city in the United States of America and the second-largest city within the state of Texas, with a population of 1.33 million. Located in the American Southwest and the south–central part of Texas, the city serves as the seat of Bexar County. In 2011,...

. They produced a wide variety of electronics kits, and later complete computer systems.

In the 1960s, many hobbyist electronics magazines such as Popular Electronics
Popular Electronics
Popular 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...

and Radio-Electronics
Radio-Electronics
Radio-Electronics was an American electronics magazine that was published under various titles from 1929 to 2003. Hugo Gernsback started it as Radio-Craft in July 1929. The title was changed to Radio-Electronics in October 1948 and again to Electronics Now in July 1992. In January 2000 it was...

published construction articles, for many of which the author would arrange for a company to assemble a kit of parts to build the project. Daniel Meyer published several popular projects and successfully sold his kits. He soon started selling kits for other authors such as 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...

 and Louis Garner. Between 1967 and 1971 SWTPC sold kits for over 50 Popular Electronics articles. Most of these kits were intended for audio use, such as hi-fi
High fidelity
High fidelity—or hi-fi—reproduction is a term used by home stereo listeners and home audio enthusiasts to refer to high-quality reproduction of sound or images, to distinguish it from the poorer quality sound produced by inexpensive audio equipment...

, utility amplifier
Amplifier
Generally, an amplifier or simply amp, is a device for increasing the power of a signal.In popular use, the term usually describes an electronic amplifier, in which the input "signal" is usually a voltage or a current. In audio applications, amplifiers drive the loudspeakers used in PA systems to...

s, and test equipment such as a function generator
Function generator
A function generator is a piece of electronic test equipment or software used to generate different types of electrical waveforms over a wide range of frequencies. These waveforms can be either repetitive or single-shot, in which case some kind of triggering source is required...

 based on the Intersil
Intersil
Intersil Corporation is an American company that specializes in the design, development and manufacturing of high-performance analog semiconductors for four high-growth markets — Communications, Computing, High End Consumer and Industrial.-Company history:...

 ICL8038.

In 1972 SWTPC had a large enough collection of kits to justify printing a 32 page catalog. In January 1975 SWTPC introduced a computer terminal kit, the "TV Typewriter
TV Typewriter
The TV Typewriter was a video terminal that could display 2 pages of 16 lines of 32 upper case characters on a standard television set. The Don Lancaster design appeared on the cover of Radio-Electronics magazine in September 1973. The magazine included a 6 page description of the design but...

", or CT-1024. By November 1975 they were delivering complete computer kits based on Motorola MPUs. They were very successful for the next 5 or so years and grew to over 100 people. Most of the companies that were selling a computer kit in 1975 were out of business by 1978. Around 1987, SWTPC moved to point of sale
Point of sale
Point of sale or checkout is the location where a transaction occurs...

 computer systems. The original company was terminated about 1990 and became Point Systems. This new company lasted only a few years.

Microcomputer pioneers

When 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 (CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...

 chips
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...

) became available, SWTPC became one of the first suppliers of microcomputer
Microcomputer
A microcomputer is a computer with a microprocessor as its central processing unit. They are physically small compared to mainframe and minicomputers...

s to the general public, focusing on designs using the Motorola 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...

 and, later, the 6809
Motorola 6809
The Motorola 6809 is an 8-bit microprocessor CPU from Motorola, designed by Terry Ritter and Joel Boney and introduced 1978...

 CPUs. Many of these products were available in kit form as well. SWTPC also designed and supplied computer terminals, chassis, processor cards, memory cards, motherboards, I/O cards, disk drive systems, and tape storage systems. From the older "TV Typewriter" design a Video terminal had evolved the CT-64 terminal system, which was an essential part of many early SWTPC systems. Later a more intelligent version of this terminal, the CT-82, was introduced, and a graphical terminal the GT-6144 Graphics Terminal. Still later a SS-50 bus plug-in board, the "Data Systems 68 6845
Motorola 6845
The Motorola 6845 is a video address generator first introduced by Motorola and used among others in the Videx VideoTerm display cards for the Apple II computers, the MDA and CGA video adapters for the IBM PC, in the Amstrad CPC and the BBC Micro. Its functionality was duplicated and extended by...

 Video Display Board
Video Display Controller
A 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...

" was introduced, and a keyboard could be connected to this board. With this solution an external terminal was no longer needed.

SWTPC's SS-50
SS-50 Bus
The SS-50 bus was an early computer bus designed as a part of the SWTPC 6800 Computer System that used the Motorola 6800 CPU. The SS-50 motherboard would have around seven 50-pin connectors for CPU and memory boards plus eight 30-pin connectors for I/O boards...

 backplane
Backplane
A backplane is a group of connectors connected in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors forming a computer bus. It is used as a backbone to connect several printed circuit boards together to make up a complete...

 bus
Computer bus
In computer architecture, a bus is a subsystem that transfers data between components inside a computer, or between computers.Early computer buses were literally parallel electrical wires with multiple connections, but the term is now used for any physical arrangement that provides the same...

 was also supported or used by other manufacturers: (Midwest Scientific Inc, Smoke Signal Broadcasting, Gimix, Helix
Helix (company)
Helix is a family run United Kingdom based manufacturer of scholastic stationery. It currently employes 75 people, and exports to over 65 countries, with offices in Chicago and Hong Kong and with UK headquarters based in Lye, West Midlands.- History :...

, Tano, Percom Data, Safetran
Safetran
Safetran Systems Corporation is a US-based supplier of switch machines, railroad wayside signal systems, rail transit signaling and rail-highway grade crossing active warning systems....

), etc. It was extended to the SS-64 (for the 68000 CPU) by Helix. SWTPC also designed one of the first affordable printers available for microcomputer users; it was based on a receipt printer mechanism.

Technical Systems Consultants
Technical Systems Consultants
Technical Systems Consultants was a US software company.Headquartered first in West Lafayette, Indiana and later moved to Chapel Hill, North Carolina, it was the foremost supplier of software for SWTPC compatible hardware, as well as many other early makes of personal computers...

, first of West Lafayette, Indiana (ex Purdue University) and later of Chapel Hill, North Carolina, was the foremost supplier of software for SWTPC compatible hardware. Their software included operating systems (Flex
FLEX (operating system)
The FLEX single-tasking operating system was developed by Technical Systems Consultants of West Lafayette, Indiana, for the Motorola 6800 in 1976. The original version was for 8" floppy disks and the version for 5.25" floppies was called mini-Flex. It was also later ported to the Motorola 6809;...

, mini-FLEX, FLEX09, and UniFLEX
UniFlex
UniFLEX is a Unix-like operating system developed by Technical Systems Consultants for the Motorola 6809 family which allowed multitasking and multiprocessing. It was released for DMA-capable 8" floppy, extended memory addressing hardware , Motorola 6809 based computers. Examples included machines...

) and various languages (several BASIC variants, FORTRAN, Pascal, C, assemblers, etc.) and other applications. Other software, from third parties, included Introl's C
C (programming language)
C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....

 compiler
Compiler
A compiler is a computer program that transforms source code written in a programming language into another computer language...

, Omegasoft's Pascal compiler, the Lucidata Pascal system (from Cambridge, UK), and assorted spread sheets and text processors. By about 1980, TSC had developed a Unix-like multi-user, multi-programming operating system (UniFlex), for 6809 systems with DMA 8" floppy disks and extended memory. Several of TSC's languages were ported to the UniFlex, as was the Lucidata Pascal system.

SWTPC was a pioneer of open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...

software. Their software catalog included the TSC software, and software from many other sources (including SWTPC itself). Much of it was available in source code—for a higher cost.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK