user input timeouts?

[bob at sinister.com (Bob Keyes)]

I am working on a 2 floppy linux disttribution, and I want it to be able
to make some intelligent decisions when it is operating unattended but
still allow a user at the console to interrupt some startup procedures.

So, I want basically this: User is given a period of time (8 seconds or
so) to either hit Y to to continue or N to abort, and if they fail to take
action within that time, a default action will occur.

I am doing this on a small system, like I said, and have busybox and ash
at my disposal. I could probably write a C program to do it but would
rather not. Anyone have any ideas?