25 Sep
2010
25 Sep
'10
1:30 p.m.
Brass threaded PCB standoffs in early Taiwanese
systems were
sometimes an interesting mixed bag--the threaded stud was often
imperial, while the threaded hole was metric.
The classic example of this is the jackposts on HPIB connectors. The male
end (to fit into the socket/panel) is often 6-32 UNC (expeically in HP
machines), although I have seen metric theads in, say an Epson printer
[1]. The female part, to take the screw in the cable connectors is M3.5
(!) now, early ones were 6-32 UNC. The convention for real HP
cables/jackposts was taht nickel-plated (shiny metal) screws/posts are
UNC, black oxide ones are metric, but I've seen plenty of shiny metric
ones on other eqyipment.
[1] There was an HPIB interface board for classic Epson dot-matrix
printers. It fits into the intenral interface connector normally used for
a serial option.
-tony