Gaps in the collection (was Re: rarest computers. )

From: J. David Bryan <jdbryan_at_acm.org>
Date: Fri Aug 6 12:02:59 2004

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
Received on Fri Aug 06 2004 - 12:02:59 BST