The Xerox Sigma 9, also known as the XDS Sigma 9, is a high-speed, general purpose computer.
 Living Computer Museum - Xerox Sigma 9 | |
| Developer | Xerox |
|---|---|
| Product family | Xerox Sigma |
| Release date | 1970 |
Xerox first became interested in office automation through computers in 1969 and purchased Scientific Data Systems or SDS. They then renamed the division Xerox Data Systems or XDS; they saw limited success, and the division was ultimately sold to Honeywell at a significant loss.[1]
The Sigma 9 was announced in 1970 and the first delivery was made in 1971.[2] There were 3 models built, the Sigma 9, the Sigma 9 Model 2 and the Sigma 9 Model 3. The original was the most powerful and was universally applicable to all data processing applications at the time. The Model 2 was able to process in multi-programmed batch, remote batch, conversational time-sharing, real-time, and transaction processing modes. The Model 3 was designed for the scientific real-time community.
Features of the Basic Systems
editAll models featured a CPU with at least a floating-point arithmetic unit, Memory map with access protection, Memory write protection, Two real-time clocks, a Power fail-safe, an External interface, Ten internal interrupt levels. Also a Multiplexor input/output processor (MIOP) featuring Channel A with eight sub-channels.[3]
Listed below are the individual specifications
Sigma 9
edit- CPU featuring:
- Decimal arithmetic unit
- Two 16-register general purpose register blocks
- Interrupt control chassis with eight external interrupt levels
- Memory reconfiguration control unit
Model 2
edit- CPU featuring:
- Decimal arithmetic unit
- Two 16-register general purpose register blocks
- Interrupt control chassis with two external interrupt levels
- Main Memory of 32K words
Model 3
edit- CPU featuring:
- One 16-register general purpose register blocks
- Interrupt control chassis with two external interrupt levels
- Main Memory of 32K words
References
edit- ^ "Exhibits - Living Computer Museum". www.livingcomputermuseum.org. Retrieved 12 July 2016.
- ^ "Sigma9 Sales Guide" (PDF). Retrieved 12 July 2016.
- ^ Xerox Sigma 9 Reference Manual. El Segundo, California: Xerox. June 1972.
Further reading
edit- Sigma 8, 9 Withdrawal Pains Eased With Independent Memory. (1979). DM, Data Management, 17(2), 24.