SCELBI
Encyclopedia
SCELBI Computer Consulting was a personal-computer hardware and software manufacturer located in Milford, Connecticut
. It was founded in 1973 by Nat Wadsworth and Bob Findley. Initially, they sold hardware (called the SCELBI-8H) based on the first 8-bit microprocessor from Intel, the 8008
. The 8H came with 1K of random-access memory
and was available either fully assembled or in a kit (consisting of circuit boards, power supply
, etc that the purchaser assembled). Some sources credit SCELBI being the first (March 1974, p. 154) advertised personal computer sold in kit form, with advertisements in QST
, Radio-Electronics
and later in BYTE
magazine.
SCELBI soon had competitors. In July 1974 Radio-Electronics published plans for a similar 8008 machine, called the Mark-8
that skilled hobbyists could fabricate for the cost of parts. Companies like MITS
started selling systems based on more capable processors, such as the 8080
used in the MITS Altair 8800
. SCELBI responded by introducing the SCELBI-8B model with 16K of memory, the limit on the 8008.
No high-level programming language
was available for the 8H in the beginning. Wadsworth wrote a book, Machine Language Programming for the 8008 and Similar Microcomputers, that taught the assembly language
and machine language programming techniques needed to use the 8H. The book included a listing of a floating point
package, making it one of the first examples of non-trivial personal-computer software distribution in the spirit of what would much later become known as open source
. Because of the similarities between the 8008 and the 8080, this book was purchased by many owners of non-SCELBI hardware.
SCELBI discovered that they made more money selling software books than hardware and the business switched to highly documented software published in book form, including many games, a monitor, an editor, an assembler, and a high-level language dubbed SCELBAL (a dialect of BASIC
that incorporated Wadsworth's floating-point package) to compete against Altair BASIC
.
Milford, Connecticut
Milford is a coastal city in southwestern New Haven County, Connecticut, United States, located between Bridgeport and New Haven. The population was 52,759 at the 2010 census...
. It was founded in 1973 by Nat Wadsworth and Bob Findley. Initially, they sold hardware (called the SCELBI-8H) based on the first 8-bit microprocessor from Intel, the 8008
Intel 8008
The Intel 8008 was an early byte-oriented microprocessor designed and manufactured by Intel and introduced in April 1972. It was an 8-bit CPU with an external 14-bit address bus that could address 16KB of memory...
. The 8H came with 1K of random-access memory
Random-access memory
Random access memory is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order with a worst case performance of constant time. Strictly speaking, modern types of DRAM are therefore not random access, as data is read in...
and was available either fully assembled or in a kit (consisting of circuit boards, power supply
Power supply
A power supply is a device that supplies electrical energy to one or more electric loads. The term is most commonly applied to devices that convert one form of electrical energy to another, though it may also refer to devices that convert another form of energy to electrical energy...
, etc that the purchaser assembled). Some sources credit SCELBI being the first (March 1974, p. 154) advertised personal computer sold in kit form, with advertisements in QST
QST
QST is a magazine for amateur radio enthusiasts, published by the American Radio Relay League . It is a membership journal that is included in membership with the ARRL. The publisher claims that circulation of QST in the United States is higher than all amateur radio-related publications in the...
, 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...
and later in 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...
magazine.
SCELBI soon had competitors. In July 1974 Radio-Electronics published plans for a similar 8008 machine, called the Mark-8
Mark-8
The Mark-8 is a microcomputer design from 1974, based on the Intel 8008 CPU . The Mark-8 was designed by graduate student Jonathan Titus and announced as a 'loose kit' in the July 1974 issue of Radio-Electronics magazine.- Project kit :The Mark-8 was introduced as a 'build it yourself' project in...
that skilled hobbyists could fabricate for the cost of parts. Companies like MITS
Micro Instrumentation and Telemetry Systems
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...
started selling systems based on more capable processors, such as the 8080
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...
used in the MITS Altair 8800
Altair 8800
The 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...
. SCELBI responded by introducing the SCELBI-8B model with 16K of memory, the limit on the 8008.
No high-level programming language
High-level programming language
A high-level programming language is a programming language with strong abstraction from the details of the computer. In comparison to low-level programming languages, it may use natural language elements, be easier to use, or be from the specification of the program, making the process of...
was available for the 8H in the beginning. Wadsworth wrote a book, Machine Language Programming for the 8008 and Similar Microcomputers, that taught the assembly language
Assembly language
An assembly language is a low-level programming language for computers, microprocessors, microcontrollers, and other programmable devices. It implements a symbolic representation of the machine codes and other constants needed to program a given CPU architecture...
and machine language programming techniques needed to use the 8H. The book included a listing of a 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...
package, making it one of the first examples of non-trivial personal-computer software distribution in the spirit of what would much later become known as 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...
. Because of the similarities between the 8008 and the 8080, this book was purchased by many owners of non-SCELBI hardware.
SCELBI discovered that they made more money selling software books than hardware and the business switched to highly documented software published in book form, including many games, a monitor, an editor, an assembler, and a high-level language dubbed SCELBAL (a dialect of 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....
that incorporated Wadsworth's floating-point package) to compete against Altair BASIC
Altair BASIC
Altair BASIC was an interpreter for the BASIC programming language that ran on the MITS Altair 8800 and subsequent S-100 bus computers. It was Microsoft's first product , distributed by MITS under a contract...
.