20 Jan
2008
20 Jan
'08
2:21 p.m.
Tony Duell wrote:
And while not a terminal, and while not triggeered by
^G, the HP9830 has
an electronic beeper used to signal errors. It's simply triggered by a
single line from the I/O interface PCB and things like the frequency and
dureation are set by r's and C's on the PCB, they're not software
controlled. But it shows the sort of design that when into these old HPs
when you realase there's a little circuit -- OK, just a couple of gates,
a trnasisotr, and a few passives -- to geenrate an amplitude envelope on
this beep to make it sound more pleasant. One machine where every cent
was _not_ saved...
-tony
I like a real bell.
PS. stupid HTML email ... you can't enter a CTL G. :(