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.


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?)


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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