It might have some use where early PC games expects a floppy drive to be slow -- giving time to view a title screen while the game is loading, for example -- but I can't think of a single game where slowing down the HD would be useful. What is your interest in such an adjustment?

for authentic doom gameplay - on my first pc some sounds was loading in same time with actions, it's make sound little laggy sometimes, but very pretty, imho. (sry, bad eng)

You could probably use some version with physfs, and mount a zip.... from a slow USB stick.

There's also the option of playing it in PCem if you want a more 'authentic doom playing' speed since that has lots of options for cache, CPUs, BIOS, even video bus speed... it can nail down authentic speed better than adjusting cycles alone.