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Thursday, November 30, 2017

Univac Document Archive: 1107 EXEC II Manual Added

I have added the following document to the Univac 1107 section of the Univac Document Archive. This is a PDF of a scanned paper document in my collection. This document is more than fifty years old and may appear wonky to contemporary eyes: text is sometimes misaligned on the page and multiple fonts are intermixed like a ransom note. These are not artefacts of scanning—it's how the document actually appears. Recall that only around 38 Univac 1107s were sold, so documents describing it were produced in small numbers and didn't, in the eyes of Univac, merit the expense of the high production values of contemporary IBM manuals.

EXEC II was originally developed by Computer Sciences Corporation (CSC) and dubbed the “1107 Monitor System”. When Univac adopted it as an alternative high-performance serial batch system, they renamed it “EXEC II”, redesignating their own multi-tasking system “EXEC I”. This manual was produced from CSC's manual by pasting corrections which changed the name of the system and some of its terminology over the original text. The replacement text was typewritten in a different font, and is obvious. Although EXEC II ran a single user job at a time, it had the ability to operate peripherals such as card readers, card punches, and line printers simultaneously with computation via interrupt-driven background tasks. CSC called these “parasites”, but Univac deemed this terminology infelicitous and renamed them “symbionts”, crudely replacing the text throughout the manual. Well, almost everywhere. Eagle-eyed readers will be amused to discover they missed a few.

EXEC II was also available for the Univac 1108, and as late as 1973 I worked for a site which still ran it. The Univac Document Archive also includes a 1966 1108 EXEC II manual which has been entirely re-set from the 1963 original and includes additional information. There was little difference between the 1107 and 1108 versions of EXEC II: on the 1108 the system did not take advantage of the 1108's memory relocation or guard mode facilities, and remained vulnerable to rogue programs which could destroy it.

Posted at November 30, 2017 23:36