C64 - Addendum to Hiding ML in REM statements

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A followup to the previous video about hiding machine language code in BASIC REM statements. I demonstrate how to Indirectly load a zero byte, without crashing BASIC and two things you shouldn't do once the ML is in place.
00:11 Title
00:42 Coin-REM source code
01:33 Coin-REM zero-byte
02:34 Adding BASIC lines
03:39 Editing the REM line
04:37 End Title

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15 окт 2024

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Комментарии : 8

@csbruce 2 месяца назад

0:52 You could also LDX #1 : DEX to get a $00. 2:00 Hidden dependencies can be dangerous. Technically, it's not the '0' digit in the "10" but the line number being ≤ 255, and the $00 is in the most-significant byte. 2:11 $800 seems more reliable, since BASIC programs won't actually RUN if location $800 isn't a $00. Though, I guess the low byte of the address is a problem.

@retrooldguy9880 2 месяца назад

Yeah you're right, I did make it sound like the line# itself should end in a zero and not the high-byte of the address holding the line number. The video does show the correct byte in the memory dump. So hopefully everyone will know what I meant 🤔

@TheUtuber999 2 месяца назад

Thanks for the tip on retrieving a zero byte indirectly. 2:08 "As long as the BASIC line number ends in a zero..." I think as long as the line number is less than 256 it should work because address $804 is the high byte of the line number.

@jack002tuber 2 месяца назад

That LDA from the line number was pretty cool. Neat stuff

@Richardddoobies 2 месяца назад

Commodore manual: "Screen memory is not an appropriate place to store machine language programs." Me: "Hold my beer." SYS 1024

@Ansatz66 2 месяца назад

It would be interesting to know why exactly hitting return corrupts the code, and why this particular corruption.

@UltimatePerfection 2 месяца назад

Can you do a review of Vision BASIC for C64? Most of the videos about it seems to come from the developer's account which hardly is unbiased. I am considering getting it, just need to see some benchmarks to see if it's really much faster than regular BASIC to make c64 games with.

@networkg 2 месяца назад

@UltimatePerfection I bought a copy of Vision Basic and can tell you that if you enjoy programing for a C64, you will love it. It is very fast. Like 7 to 10 times faster. Even more so if you use machine language mixed in with the basic. The guy who wrote it is getting ready to release a version 1.1 which should offer a few improvements. Although it will be a free upgrade, you might want to wait so you can get the updated manual which I hear will have a much requested feature, an index ! You do need an REU or GeoRam (version 1.1 will support this I think) but for me, I just do all my programming in VICE and then run the compiled code on a standard C64.