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Rod Speed Rod Speed is offline
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Default small potentiomenter with switch

"whisky-dave" wrote in message
On Saturday, 24 April 2021 at 03:55:58 UTC+1, Rod Speed wrote:
"whisky-dave" wrote in message
On Friday, 23 April 2021 at 23:14:34 UTC+1, Rod Speed wrote:
"whisky-dave" wrote in message
On Friday, 23 April 2021 at 21:11:43 UTC+1, Peter Able wrote:
On 23/04/2021 11:31, whisky-dave wrote:
On Wednesday, 21 April 2021 at 19:42:11 UTC+1, Peter Able wrote:
On 21/04/2021 13:29, whisky-dave wrote:
On Wednesday, 21 April 2021 at 12:18:47 UTC+1, Peter Able
On 20/04/2021 22:17, whisky-dave wrote:
On Tuesday, 20 April 2021 at 20:09:11 UTC+1, Peter Able
On 20/04/2021 11:47, whisky-dave wrote:
Does anyone know where I can buy those old school type
potentiomenter with switch you know the ones like they had
first hand held radios in the 60s-70s and on walkmans and
just a little wheel and the click for volume control. And
of course

I know I could by the standard rather large pots with DSPT
want to put
this thing inside a mouse (computer mouse that is) .

Get one out of a scrap radio is the literal answer.

Tell us about the mouse project !

It's for a small project to get students (those interested in
hardware) to adapt an old mouse or we can supply one
so they can have rapid fire button with speed adjust. So need
switch it off for normal use too.
unfortunately these seem more expensive (over £3) than the
buy ;-)

yes I know there maybe a software solution but we need to
more than just keyboard kiddies to hardware.

looking to buy 20-40

Respect! That's a brilliant project.

"thumbwheel potentiometer switch" produces 25 10k log taper
£30 on ebay.

Hope you don't need LINear. !


Cheers althouth TBA these type may be a problem mounting on a
Currently using a finger preset

Although it appears just adjusting the frequence of a 555 or
ratio doesn;t give a very good range.
Seem both frequency and M/S may need tweeking which is a pain.

now need to find a small , cheap, round mount hole switch.

We try to run 4 or 5 of these type activities a year for
they aren't marked or compulsary
just a fun activity but the days of using a LED , 555 based egg
are well gone.
Need to think of something that can't be done on a phone or
students can show off to friends.

Good luck then.

Incidentally you could probably do what you want to do with two
press or touch switches - and a microcontroller. Shoving your
in at the deep end, I guess - but it could be a forward-looking

Far to advanced and difficult to do., due to size restriction.
These are 1st year students even final year students would have
problems with that.

And it could then simulate LOG, LIN, Ballistic or whatever.

No point as the interface on the computer wouldn't see that

And make LEDs flash !

No that's more like it. :-)

You might be surprised!

I'm sure you'd be more surprised by the level our student tend to be

s When I was at University - late 60s -

In those days the bright went to university,

Not just those, the more stupid trained to be teachers there.

It depended on where their interest were, a few of our ex
students are now lectures, one became head of department.

I meant school teachers.

Even nurses are uni qualified now.

They need to be it;s no longer just emptying bedpans lots of tech
and medical theory need nowerdays.

now it is more for those that can't get a job after leaving school.


We get a quite a few from "Clearing" which is those that have failed to
into their preferred courses they have applied to study, so they lack
relatively high grades in physics and maths that are needed so fall

Thats nothing like your previous. And isnt true of arts students either.

I was referring to those in the engineering departments

seemed to have heard of devices with more than four pins - and the
of system engineering was unheard of. I broke the mould with a mass

TTL ! the first chips I can across were DTL when working as a school

The first I used was RTL.

Still a step up from valves

The second two computers I used were discrete transistors.
The IBM 360/50 was SLT but I didnt do the maintenance on that one.

First computer in my lab early 1979 was a PDP11/34
costing £7,700 about 40K in todays money

First computer in mine was in 1965, PDP8/S the serial one.
Only vague memory of the price, something like $30K then.
Only IO was an ASR 33 teletype with 10 cps paper tape
reader and punch. Loading Focal, similar to Basic took
an hour or so and it could give you a checksum error
at the end of the load so you had to start again.

I drove the IBM 360/50 that was the main computer the uni
had at night. That had punched cards for input and output
and a massive great printer bigger than a Leyland Mini car.

Move to a different operation in 69 which had a PDP9.
No idea what that cost. That had 300 cps optical paper
tape reader and punch. We later added a fixed head
hard drive and later again a 9 track mag tape.

The PDP9 was discrete transistors on plug in cards,
geranium transistors too, not silicon. We stole the
DEC design of the interface between the PDP9 and
the PDP15, the TTL version of the PDP9 and made
our own pcbs which allowed the use of the magtape.
I did the mag tape controller using TTL wire wrapped
on a draw full of individual wire wrap sockets of TTL.

We did our own OS for the PDP9 using the same
concept as TSX for the PDP11 for multitasking.

Then added a PDP11/AD which was the node for the
country wide network that allowed the use of the
CDC 3600 and later 7800.

The PDP9 had 11/23s added later and then a microvax.

I did all the hardware and maintenance for
all that stuff except the central CDC gear.
but the thing everyone came in the lab to be hypnotised by was a
relatively simple pseudo binary sequencer used to try to break the
design. It ran at many megabits per second, but I included four
Lilliput bulbs driven by certain bits of the pbs, but only updated

A real crowd puller!

Well this is why we are trying to find activities that get their
interest and put their smartphones away.