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Comment by classichasclass | Hacker News Reader

6502 was my first assembly, though we didn't have an assembler - we entered raw opcodes into the Epyx FastLoad monitor on the C64. You kids with your symbol tables and your fancy mnemonics.

a9 01 8d 20 d0 a9 93 20 d2 ff ...

When we got a KIM-1, we were able to write meaningful programs on it in a weekend, since we already had memorized all the hex.

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I've forgotten so much of that, but I'll go to my grave remembering that

  LDA #97
  JSR $FFD2

writes "A" to the screen.

Funny. I still remember it $FDED on the Apple // series. But printing text out like that was really slow. For fast text printing you had to write to memory locations between $400-$7FF and deal with the non continuous memory block -> screen location mapping.

It was even more of a pain with 80 columns when half of the text was in the main memory and the other half was the bank switched memory.

Ouch. That sounds painful. Yeah, I usually ended up writing to screen RAM at $400. It was convenient to let the kernal manage cursor position and all that, though.

Yeah, in 40 column mode, each row was separate by 320 bytes. In 80 column mode, each even character on a line was in main memory and each odd column was in the second 64K block in extended memory.

I’m certain there was a good reason for that. Woz was an engineer’s engineer. But wow, I can’t imagine what it would’ve been.

Even on the Apple //e you could “call -151” to get into the assembler and then type “!” to use the mini assembler

Not on the Microsoft laden Apple ][+ - they removed that... :`(

Only on the OG Integer ROM Apple ][ and then again on the later 1985 enhanced ROM //e

White border with a cleared screen looks good.

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