| Company type | Public |
|---|---|
| Industry | Microcomputer Software |
| Founder | Robert Shepardson |
| Defunct | 1981 |
| Successor | Optimized Systems Software |
| Headquarters | , United States |
Shepardson Microsystems, Inc. (SMI) was a small company producing operating systems and programming languages for CP/M, the Atari 8-bit computers and Apple II. SMI is most noted for the original Apple II disk operating system, Atari BASIC, and Atari's disk operating system. Shepardson Microsystems was founded by Robert Shepardson in Saratoga Springs, New York.