Tony Duell beat me to this when he wrote: "There have been many devices which implemented the IEEE-488 bus (GPIB, HPIB) using a standard parallel interface chip like the 6821 or 6522 together with buffers." My Osborne 1 (Z80, 64K, CP/M, 5 1/4 floppies, tan case, '82) labeled their parallel port "IEEE-488" (aka HP-IB) and wrote low level routines for the eight basic HP-IB commands into the bios. They used a 6821 PIA to drive the port, an interesting mixing of chip families. My computer whiz high school son and I built some software around their stuff and I used the Osborne (personal) at work (DOD R&D) for several years to talk to, among other stuff, Nicolet digital scopes. I don't remember much about the details and don't know whether I can find anything useful, or readable, on the software, but the bios routines should be available in the Osborne tech literature. I still have the Oborne, but haven't tried to run it for several years, will have to see if it still lights. My next laptop was a Toshiba T1200 (80C86, 1MB, 3.5 floppies only, MSDOS, '89) which had a bidirectional parallel port implemented in a custom gate array with eight additional control signals. I remember that we tried to do a klunge to run '488 on that but can't for the life of me remember whether we were ever successful. I'll have to dig around some more in the old stuff and see what I can find. Good luck on the project Vassilis. Dave Dykstra, Tucson Vassilis Prevelakis wrote: and: etc