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Retrocomputing

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    You missed an important step: poking characters into the keyboard buffer (poke 198 to set the count, and 631-640 to set the actual characters). Code would typically print the code two lines from the top of the screen, followed by a "RUN [someLine]", and then poke enough returns into the buffer for all the lines and the RUN, then home the cursor and exit. Commented Jun 8, 2019 at 17:30
  • It would also have been possible, and not even very difficult, to use poke to modify a program that was running, provided that before creating any variables one would need to keep, one adjusted the end-of-program address as needed and then did a CLR. Commented Jun 8, 2019 at 17:32
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    Using POKE is explicitly excluded in the question. Commented Jun 8, 2019 at 19:35
  • @supercat I wasn't really going for a complete 'how-to' tutorial, merely trying to outline the basic (hah!) principle behind the technique. Commented Jun 9, 2019 at 19:35
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    @berendi: Outputting to the screen wouldn't achieve automatic self-modification unless one POKEs keystrokes into the buffer as mentioned. Commented Jun 9, 2019 at 22:23