Original source code for the IBM CP/67 CMS operating system from 1973

This is the original source code for the IBM CP/67 CMS operating system from 1973.

The source is in assembly listing format as produced by the S/360 assembler for CP/67.

This source code was recovered from tape reels found in a dumpster (literally!) and then converted to digital .aws format. The format is in very told VM TAPE format not directly usable on today’s z/VM (which is the grand-grand-grandchild of CP/67). So I read the tapes into VM/370 which is still close enough to CP/67 to be able to read the tape format.

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Excellent! We don’t very often hear about recovery from magtape.

Lots of comments in the source. And the lovely listing file lacks only the green bars.

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You just have to print it on your 1403 to get the green bars back :slight_smile:

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I’m really impressed by the source code and the kind of discipline that went into this.
(Is there even a single instruction without comments?)

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We used to snicker at AIX that it was like old IBM big iron beards were given the X/Open docs and told to clean-room a UNIX, but I couldn’t fault their documentation.

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