SCELBI (SCientific ELectronic BIological, pronounced "sell-bee") 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 and IMSAI started selling systems based on more capable processors, such as the 8080 used in the MITS Altair 8800 and IMSAI IMSAI 8080. 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.