2 Jan
2026
2 Jan
'26
11:05 a.m.
On Fri, Jan 2, 2026 at 6:59 PM Paul Koning <paulkoning(a)comcast.net> wrote:
I checked the printset after posting. The 'buzz' is generated by
pulsing the coil from the firmware, it doesn't use the normally-closed
relay contact to make a buzzer.
On Jan 1, 2026, at 10:56 PM, Tony Duell via
cctalk <cctalk(a)classiccmp.org> wrote:
On Thu, Jan 1, 2026 at 11:44 PM Nigel Williams via cctalk
<cctalk(a)classiccmp.org> wrote:
That's what the schematic shows, or more precisely it shows a relay coil, I can't
find the actual part description.
Anyone know why DEC chose to use the grind-noise? it was a singularly
unpleasant sound, it had the effect of not wanting to trigger it.
From what I remember it's actually a little relay on the main circuit
board. A single pulse for the key click and a buzz for the 'bell'
-tony
Curiously enough, the earlier VT05 does have a proper beeper, with an 800 Hz oscillator
feeding a speaker.
I looked in that printset too. A real speaker.
Years ago I could have rescued a VT05. Alas the car was full
(PDP11/44, PDP8/e, Acorn System 4, Northstar, Sun 3/260, manuals, etc)
and I never went back for it. Been kicking myself ever since.
And the VT61/t, which is a block editing terminal for
Typeset-11 in a VT52 case, also has a speaker for the key click (and I assume for the
bell/beep though I didn't look that far). Then again, it's not clear whether the
VT61/t has anything in common with the VT52 other than its case and perhaps the CRT and
some of the power supplies. I remember a collection of rather hairy looking circuit
boards, the final last gasp of single-sided PCB technology with hundreds of jumper wires
on the component side...
I think the VT52 is a pair of single-sided boards with lots and lots
of wire jumpers. I've never actually seen inside one, I have a VT55
with AFAIK is a VT52 with the line/histogram board added. That is a
double-sided (at least) PCB.
-tony