> My recollection is that most CP/M programs were configured via patching. At least that’s how I configured them. I remember my WordStar manual coming with details about which bytes to patch to do what. There was also a few dozen bytes of patch space set aside for you to write your own subroutines, in case you needed to add custom support for your printer.

Huh. That is interesting, it was before my time, and I never heard of this :D

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zabzonk 3 hours ago | parent [-]

Yes, it was definitely a thing. The patching code had to be in Z80/8080 machine code. I wrote higher performance keyboard and display routines for my copy of Wordstar using this feature.

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Semaphor 2 hours ago | parent [-]

Stuff like that is also cool (reminds me a bit of modding some games), patching machine code to improve performance of a compiled app? Very cool! (My dad might have done that, he has an old ZX81)

But I thought specifically patching something to configure it is such a weird concept that I never would have thought of.

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matt_kantor an hour ago | parent [-]

The line between "configuration" and "modding" is pretty thin.

One could say that the difference is whether the developers intended the changes you're making to be possible or not, but what about programs with dedicated modding APIs?

	▲	zabzonk an hour ago \| parent [-]
		At the time (early to mid 1980s) I think we would say "patching". The Wordstar devs certainly did mean you to do this - the memory locations available were fully documented, and I seem to remember they supplied a small patch utility to incorporate your code into the Wordstar executable.