#1 is the main reason I hack on old stuff, #3 is also present. The 6502 in particular is a nice choice since they're still made and available (Mouser carries t

#1 is the main reason I hack on old stuff, #3 is also present. The 6502 in particular is a nice choice since they're still made and available (Mouser carries them), there's a zillion vintage things that use them if you want something actually old, there's hobbyist kits/preassembled if you want something new, and it's a super easy CPU to interface to, especially for trivial cases.