Ayy, after a lot of debugging, my ring buffer copying code for #mos6502 works!!!
I only made like 8 embarrassing mistakes in the process, but hey, #assembly is hard. And fun!
So, #65cha02 is back on track. Now to incorporate the ring buffer code into a machine monitor...
#theWorkshop #theFoundry

Heavily commented source code, for anyone curious: https://git.sr.ht/~raingloom/six_five_chaos/tree/779890c68987607806732592bf7905eede71df32/item/asm/ringecho.s