weaponepsilon wrote:
27c512s, 27128s
These are too small to be useful for most NES stuff. The 27C512 can hold 64KB, and the 27C128 can hold 16KB, and only the earliest NES games have less than 64KB of PRG-ROM and 16KB of CHR-ROM. Almost anything after 1987 or so has at least 128KB.
If you're programming your own stuff though, or using homebrews from other people, then these chips are certainly useful. Most NES programmers nowadays don't make big games. EPROMs are a pain in the ass to erase though, they need to stay several minutes under direct UV light, so you probably don't want to use them during development, only for final carts.
I often (well, I hardly do any hardware work nowadays, since Flash carts are so convenient, but still...) use Flash ROMs. The 29CXXX line to be exact. Flash and EEPROMs are way more convenient than EPROMs, because they can be erased in seconds in the same device you use to program them.