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.

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driggs 18 minutes ago | parent | next [-]

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.

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zabzonk an hour ago | parent | prev [-]

could you quote the text you are referring to?

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fooqux an hour ago | parent [-]

"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."

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flohofwoe 40 minutes ago | parent [-]

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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rendaw 25 minutes ago | parent [-]

I was curious seeing this thread, and I just looked and don't get it either. AFAICT the CP/M references could have been entirely omitted and nothing in the narrative about TMP and TEMP would change.

	▲	jodrellblank 10 minutes ago \| parent [-]
		Except that DOS was made to have its first programs ported from CP/M, so it’s relevant to explain that there were no environment variables to inherit from CP/M and no developer habits or program standards to inherit from CP/M programs.