Re: Very old disused computers;

Almost any old computer can be linked into a Windows installation using the MSDOS Interlink utility. Link it serial-to-serial and you have access to all the ports and drives it can support. Boot it first as Interserver, then the main computer. The Windows system will display the drives as demountable drives. That old computer can be used as a print server - gives you an extra parallel port, and lets the printing download into the "slave" computer memory. Gives you the potential to add drives, as long as the bios + drivers will support them.