| Company type | Public |
|---|---|
| Industry | Microcomputer Software |
| Founder | Robert Shepardson |
| Defunct | 1981 (1981) |
| Successor | Optimized Systems Software |
| Headquarters | , United States |
Shepardson Microsystems, Inc. (SMI) was a small company producingoperating systems andprogramming languages forCP/M, theAtari 8-bit computers andApple II. SMI is most noted for the original Apple II disk operating system,Atari BASIC, and Atari'sdisk operating system. Shepardson Microsystems was founded by Robert Shepardson inSaratoga Springs, New York.
The company got its start in the microcomputer arena by producing a series ofBASIC programming language interpreters for the burgeoningS-100 bus computer market. Their first product was Cromemco 16k BASIC, which, as the name implies, was intended to run onCromemco Z-seriesZ80-based computers with 16 kB ofRAM.[1]
As machines shipped with ever-increasing amounts of RAM, due largely to the replacement ofSRAM with the much denserDRAM in the mid-1970s, SMI further expanded their version as the 26 kB Cromemco Structured BASIC, while a cut-down 12 kB version was released as CP/A Business BASIC.[1]
At the time they were written,Microsoft BASIC was widespread but not as universal as it would be by the early 1980s. SMI's BASICs were based on the concepts and syntax ofData General Business Basic (which was very similar toHP Time-Shared BASIC), as opposed toDigital'sBASIC-PLUS that formed the basis for MS BASIC. As a result, SMI's BASICs incorporated a different way to handle strings and input/output,[1] a difference that would be seen in their later languages for the Atari.
On April 10, 1978, Shepardson Microsystems signed a contract withApple. For$13,000 —$5,200 up front, and$7,800 on delivery, and no additional royalties — Shepardson Microsystems would buildApple DOS, Apple's firstdisk operating system — and hand it over just 35 days later. For its money, Apple would get afile manager, an interface forInteger BASIC andApplesoft BASIC, and utilities that would allow disk backup, disk recovery, and file copying. Apple provided detailed specifications, and early Apple employeeRandy Wigginton worked closely with Shepardson's Paul Laughton as the latter wrote the operating system withpunched cards and aminicomputer.[2] That deal enabled release and sales of Apple's Disk II drive.
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Atari, Inc. planned to follow up its successfulVideo Computer System console with more powerfulhome computers (theAtari 400 and 800), to be introduced at the January 1979Consumer Electronics Show. A version ofMicrosoft BASIC for theMOS 6502 had been licensed for the systems, but the task of retrofitting the code into an 8kcartridge proved too difficult.
Atari turned to Shepardson Microsystems to help with the port, but after struggling with it themselves, they proposed developing a new BASIC instead of using Microsoft BASIC. Atari contracted with SMI not only forAtari BASIC, but theAtari Disk Operating System as well. SMI had their BASIC finished before the December 28, 1978 delivery of the contract, which included a $1000 bonus for early completion. In early 1981, SMI concluded that their BASIC and DOS products were not viable and permitted them, along with theAtari Assembler Editor, to be purchased by Bill Wilkinson and Mike Peters, who formedOptimized Systems Software. The new company enhanced the programs and sold them asthird-party applications.