Comment by fooqux
1 day ago
I'm confused by the CP/M reference. Author says it'll be important later then proceeds to explain how it had nothing to do with CP/M or the 8080 CPU.
1 day ago
I'm confused by the CP/M reference. Author says it'll be important later then proceeds to explain how it had nothing to do with CP/M or the 8080 CPU.
Agree, CP/M has nothing to do with the story, nor does the 8080/8086 sidetrack.
The whole story is that Microsoft just never bothered to standardize, despite using it themselves.
If CP/M had used environment variables for configuration, presumably there would have been an established standard for TMP vs. TEMP that DOS would have adopted. The real catch, however, is that CP/M didn’t have directories. Nor did DOS 1.0.
could you quote the text you are referring to?
"Rewind to 1973. The operating system common on microcomputers was CP/M. The CP/M operating system had no environment variables. That sounds like a strange place to start a discussion of environment variables, but it’s actually important."
Just a few lines below:
"Over time, programs were written with MS-DOS as their primary target, and they started to realize that they could use environment variables as a way to store configuration data. In the ensuing chaos of the marketplace, two environment variables emerged as the front-runners for specifying where temporary files should go: TEMP and TMP."
And before that there are a few paragraphs describing the migration of applications from i8080/Z80 based CP/M towards x86 based DOS via mechanical translation.
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