5" floppy?.

Very early HPIB stuff, I think before the IEEE-488 standard was produced used 6-32 UNC jackscrews. Later on, the jackscrews were M3.5 (metric), and HP sold conversion kits for the older stuff -- a pair of jackposts for the instruments, and a set of 4 jackscrews for the cables. UNC ones were niuckel-plated, metric ones were black oxide finish, so you could easily tell them apart. Most older instruments wrre converted (for example, the HPIB interface for my 9830 was made in 1974 according to the serial number, but has metric jackposts). So if you find one with the old UNC jackposts then IMHO it should be left as it is. Of coruse this means no modern cable will fit, hence my idea to change the screws at one end of one cable to the UNC type (I'll probably have to make these...) so as to be able to link the instrument to all my other HPIB stuff. Tghe laternative is to swap the jackposts and keep the old ones with the intrument (say in a plastic bag tucked inside), but to be honest, I'd rather keep it oirignal on the outside if I can. -tony