I'm paranoid right now because I made another circuit meant for the parallel port of the PC. While all my previous experiments involving the port were successful (except for one experiment I made a long time ago), I feel I need to make some sort of protection circuit just in case my circuits in the future decide to blow the parallel port.
So my question is, if I made a miniature parallel port extension cable that's about a couple inches long and replaced all of the wires in the cable with fuses, would this be sufficient enough protection for all computers?
I'll explain by example:
If my circuit accidentally sends a logic high output to a data pin on a parallel port hardwired in SPP mode that outputs a logic low, I can see something blow up, but I'm thinking adding a fuse in series with this connection so that this "accidental" connection will blow up the fuse instead of the electronics in the computer. Is my theory correct on this?
If fuses work, what ratings and values would be best?
My circuitry runs on 5V maximum and will likely draw less than 150 mA current.
Also, can I apply this idea to the serial port (or any other port) as well but with fuses of different ratings to match the serial port?
After all, its much cheaper to blow up fuses than it is to blow up my circuit or the PC itself.