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"Programming Like It's 1979: 6502 Assembly language on the Apple ]["

Programming Like It’s 1979: 6502 Assembly language on the Apple ][

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I totally did this on the old IBM PC style of computers with DEBUG.

We used to patch programs by adding a hex 90 (NO-OPERATION) at some critical point where it’s testing to see if you have an authorized copy of the software, rendering it now open. And for years, the way you’d perform a low-level hard drive format was to boot from floppy, run DEBUG and then run the ROM routine to run it, something like G=C800:5 as I recall.

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