I knew someone who even in the early 90s was supporting a stock control database he'd written on the Commodore PET that constructed queries in 6502 assembler fr

I knew someone who even in the early 90s was supporting a stock control database he'd written on the Commodore PET that constructed queries in 6502 assembler from user input, and then loaded them onto the CPU in the drive which could then chunter away assembling output while the user-facing app continued to respond normally.