6 Aug
2004
6 Aug
'04
5:02 a.m.
On 4 Aug 2004 at 5:18, Tony Duell wrote:
Anyway, there's a little extra circuitry
(transistor, a few passives)
to provided a simple amplitude envelope. Not just a sudden start/stop
beep, but one that tails away.
No real benefit from having this, but that _was_ HP for you.
Indeed, the same thing was done in the HP 64000 workstations. They used a
555 timer for the tone generator, a one-shot for the gate, but then added a
transistor and an R-C circuit to provide a fast attack, slow decay
envelope, resulting in a characteristic "Bink!" sound.
Melodious chimes must have been an HP corporate directive back then. ;-)
-- Dave