Well worth diving into the entire site. Lots 6502 and Atari-2600-adjacent tools. Great spacewar emu and discussion posted here before: https://www.masswerk.at/spacewar/index.html
(Bracketed address ranges additionally to breakpoints, which trigger either as PC enters or exits, optional trap for "illegal instructions", and a continuous CPU log, so you may find out how you wound up in a trap, regardless wat the regular trace was set to. — In essence, all you may need to trace some run away code.)
https://www.masswerk.at/nowgobang/list/
(Bracketed address ranges additionally to breakpoints, which trigger either as PC enters or exits, optional trap for "illegal instructions", and a continuous CPU log, so you may find out how you wound up in a trap, regardless wat the regular trace was set to. — In essence, all you may need to trace some run away code.)