SDS Sigma series - Revision history

Larsbrinkhoff: /* Software */ GORDO and SEX.

2025-08-13T14:12:28Z

‎Software: GORDO and SEX.

Jnc: /* Software */ Add a basic list of what was available

2025-08-13T13:51:55Z

‎Software: Add a basic list of what was available

Jnc: The two lines were mostly program compatible within the line

2025-08-13T12:29:11Z

The two lines were mostly program compatible within the line

Jnc: /* 32-bit group */ Memory-register aliasing provides a complete set of register-to-register operations

2025-08-01T14:24:19Z

‎32-bit group: Memory-register aliasing provides a complete set of register-to-register operations

Jnc: /* Family members */ tense

2025-07-30T08:22:31Z

‎Family members: tense

Jnc: /* External links */ +Sigma CPUs

2025-07-30T08:20:40Z

‎External links: +Sigma CPUs

Jnc: /* Sigma 3 */ Fix err

2025-07-29T00:51:48Z

‎Sigma 3: Fix err

Jnc: /* 32-bit group */ +Indirect

2025-07-29T00:42:27Z

‎32-bit group: +Indirect

Jnc: List the models in the family; give instruction layouts

2025-07-29T00:31:26Z

List the models in the family; give instruction layouts

Jnc: Expand a bit

2025-07-21T08:53:01Z

Expand a bit

← Older revision		Revision as of 14:12, 13 August 2025
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	[[Programming language]]s available included [[FORTRAN]] IV, [[COBOL]], [[LISP]] 1.5, [[BASIC]], and [[APL]], as well as the Symbol, Meta-Symbol and Extended Symbol [[assembly language\|assemblers]].		[[Programming language]]s available included [[FORTRAN]] IV, [[COBOL]], [[LISP]] 1.5, [[BASIC]], and [[APL]], as well as the Symbol, Meta-Symbol and Extended Symbol [[assembly language\|assemblers]].
		+
		+	Outside SDS, the Lawrence Livermore Laboratory made their own operating system called GORDO. UCLA took GORDO and developed it further; they named the result SEX.

	{{semi-stub}}		{{semi-stub}}

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 ===16-bit group===
 Their [[instruction set]] includes 'memory reference' [[instruction]]s:
 {{16bit-header}}
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 Introduced in 1972.
 {{semi-stub}}

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-The '''SDS Sigma series''' from [[Scientific Data Systems|SDS]] was a family of 16-bit and 32-bit computers (see below). They were intended for use partially or wholly in [[real-time]] settings, but also provided [[batch processing]] facilities (also [[time-sharing]], on the 32-bit systems). This dual capability was described as "multi-use" in SDS' marketing material.
+The '''SDS Sigma series''' from [[Scientific Data Systems|SDS]] was a family of two lines of computers; 16-bit and 32-bit (see below), each mostly [[program compatible]] among members of that line. They were intended for use partially or wholly in [[real-time]] settings, but also provided [[batch processing]] facilities (also [[time-sharing]], on the 32-bit systems). This dual capability was described as "multi-use" in SDS' marketing material.
-The Sigma 6, 8 and 9 were all produced after the merger of SDS and [[Xerox]] (forming 'Xerox Data Systems', 'XDS') in March 1969. Xerox sold XDS to [[Honeywell]] in 1975; Honeywell briefly continued support of the Sigmas, but then terminated it. At that point, other companies, including [[Telefile]], Ilene Industries Data Systems, and Realtime Computer Equipment started to build and sell [[program compatible]] machines.
+The Sigma 6, 8 and 9 members were all produced after the merger of SDS and [[Xerox]] (forming 'Xerox Data Systems', 'XDS') in March 1969. Xerox later sold XDS to [[Honeywell]], in 1975; Honeywell briefly continued support of the Sigmas, but then terminated it. At that point, other companies, including [[Telefile]], Ilene Industries Data Systems, and Realtime Computer Equipment started to build and sell their own program compatible machines.
 A Sigma 7 at [[UCLA]] was the first computer connected to the nascent [[ARPANET]].
@@ Line 7: / Line 7: @@
 ==Family members==
-There were two lines of program compatible machines; a 16-bit group and a 32-bit group. All used a [[load-store architecture]].
+As mentioned, there were two groups (lines) of program compatible machines; a 16-bit group and a 32-bit group. All used a [[load-store architecture]].
 Below are thumbnail descriptions of the models in the Sigma family, in the order of their dates of introduction.

@@ Line 43: / Line 43: @@
 * X - [[Index register]] (ditto)
-Again, there are also 'copy' instructions (register-to-register operations) and conditional branch instructions.
+Again, there are also conditional branch instructions. Like the [[PDP-10]], references to the low 16. [[main memory]] locations automagically turn into references to the corresponding register; memory reference instructions thus provide a complete set of register-to-register operations (definitely on the 7 and 5; not confirmed on the others).
 ====Sigma 7====

@@ Line 7: / Line 7: @@
 ==Family members==
-There were two lines of program compatible machines; a 16-bit group and a 32-bit group. All use a [[load-store architecture]].
+There were two lines of program compatible machines; a 16-bit group and a 32-bit group. All used a [[load-store architecture]].
 Below are thumbnail descriptions of the models in the Sigma family, in the order of their dates of introduction.

@@ Line 70: / Line 70: @@
 * [http://www.bitsavers.org/pdf/sds/sigma/ sigma] - documentation on [[Bitsavers]]
 * [https://s3data.computerhistory.org/brochures/sds.sigma.1967.102646100.pdf The Sigma Family] - sales brochure; pre-dates the Xerox merger
 * [https://archive.computerhistory.org/resources/access/text/finding-aids/102733948-Calkins/102733948-Calkins.pdf Guide to the Keith G. Calkins collection on Sigma systems]

@@ Line 30: / Line 30: @@
 ====Sigma 3====
-Introduced in 1966.
+Introduced in 1969.
 ===32-bit group===

@@ Line 1: / Line 1: @@
-The '''[[SDS]] Sigma''' was a family of 32-bit [[time-sharing]] computers.
+The '''SDS Sigma series''' from [[Scientific Data Systems|SDS]] was a family of 16-bit and (later) 32-bit computers. They were intended for use partially or wholly in [[real-time]] settings, but also provided [[time-sharing]] and [[batch processing]] facilities. The Sigma 6, 8 and 9 were all produced after the merger of SDS and [[Xerox]] (forming 'Xerox Data Systems') in March 1969.
-A '''Sigma 7''' at [[UCLA]] was the first computer connected to the nascent [[ARPANET]].
+A Sigma 7 at [[UCLA]] was the first computer connected to the nascent [[ARPANET]].
-{{stub}}
+{{semi-stub}}
 ==External links==
-* [http://www.bitsavers.org/pdf/sds/sigma/ Sigma documentation on Bitsavers]
+* [http://www.bitsavers.org/pdf/sds/sigma/ sigma] - documentation on [[Bitsavers]]
-* [https://dl.acm.org/doi/pdf/10.1145/1464291.1464296 The SDS Sigma 7: a Real-Time Time-Sharing Computer]
+* [https://s3data.computerhistory.org/brochures/sds.sigma.1967.102646100.pdf The Sigma Family] - sales brochure; pre-dates the Xerox merger
 * [https://www.andrews.edu/~calkins/profess/SDSigma7.htm The Computer That Will Not Die: The SDS Sigma 7] ''Narrator: it died.''
-* [https://s3data.computerhistory.org/brochures/sds.sigma.1967.102646100.pdf Sales brochure]
+* [https://uclaconnectionlab.org/internet-museum/ 3420 Boelter Hall: Where It All Began] - UCLA Internet Museum, displaying a Sigma 7 front panel
 [[Category: 32-bit Computers]]