I'm not sure why the micro-routine website is down, but after editing my hosts file to point to its old IP address, I was able to retrieve these Renoise instrument packs they developed.
One emulates the YM2149, sampled from real hardware, Atari 1040 STE microcomputer, the other emulates the POKEY chip, sampled from real hardware, ab Atari 65 XE microcomputer.
Enjoy! (I've still yet to test them out)
The donate buttons the creator of the instruments had on their site no longer work, but if I find a way to thank them, I'll share and update here.