*fx200,3 not working

Question

*fx200,3 not working

mattgodbolt opened this issue 2 years ago · comments

Matt Godbolt commented 2 years ago

To repro:

?&3000=12
*fx200,3
call!-4
P.?&3000

should be cleared but isn't! Super odd

Tom Seddon · Answer 1 · Sat Nov 12 2022 06:28:09 GMT+0800 (China Standard Time)

Could it be the clear routine skipping the first byte of every page? - https://tobylobster.github.io/mos/mos/S-s10.html#SP4

The reset does clear (for example) &3001.

Matt Godbolt · Answer 2 · Sat Nov 12 2022 07:06:17 GMT+0800 (China Standard Time)

zomg you might be right there! One thing the reporter (over email) said was the "32K" didn't pop up, which I've noticed too. so I wonder if there's something else going on too

Tom Seddon · Answer 3 · Sat Nov 12 2022 20:16:41 GMT+0800 (China Standard Time)

I'm 99% sure you have to take extra measures to get the 32K to appear when doing CALL!-4, which is otherwise equivalent to just pressing BREAK on its own.

Matt Godbolt · Answer 4 · Sat Nov 12 2022 22:17:51 GMT+0800 (China Standard Time)

👍 thanks Tom

Danny Yates · Answer 5 · Sun Nov 13 2022 20:54:52 GMT+0800 (China Standard Time)

Yeah, the System VIA is implicated here, IIRC. It sets some state when it's powered up which the MOS checks and later clears, which is how it knows whether it's a cold (power-on) reset.