Ideas for really small slide switches?

Hello Lewin,

>>
>>Nah, all the digital cameras use it. Well, that and PAL. OTOH I can't
> 
> In a few years you won't be able to buy an NTSC television set. I don't
> like designing for a standard that already has an execution date.
> 

Just because some politicians said that NTSC is going to go that doesn't 
necessarily mean it's going to happen anytime soon. Even if the TV 
stations did go there is lots of legacy stuff that needs an NTSC input.

> 
>>imagine anyone crawling behind their PC, tipping over the coffee mug
>>while doing that, wiggling the bolts and unplugging the VGA cable. Plus
>>how do you connect that garden hose to your little card?
> 
> 
> Same problem with NTSC, by the way, and same solution - the card will
> have a flat connector of the type used on LCDs, sold by JAE and Hirose
> among others - and an adapter cable provided separately. Note that I
> don't mean an FFC connector; the cables used are more usually
> individual strands of very fine wire.


Well, for NTSC you can buy them cheaply. No bulky adapter cable. One 
side has a tiny RCA plug (for the TV), the other a digital camera plug 
where you can hardly see the contacts without a magnifier.

> 
> As for the PC issue - I am assuming that anyone with the remotest
> interest in this has spare monitors lying around all over the place :)
> If I cared to collect them, I could have 20+ 15" and 17" CRT monitors
> per week, that is AT MINIMUM how many I see thrown away at work and on
> the streets I traverse while walking my dog.
> 
> 
Not out here. They are usually recycled, for example by participating in 
the Dell return program. Then they are gone for good. The others are 
plugged into CAD stations and the like.


>>How about a very thin metallization on top of each LED and using that as
> 
> 
> Practical to do by hand?!!
> 

I don't know whether you can metallize by hand, it was just a 
suggestion. Theoretically it should be possible if you could apply a 
peel-off mask or something.


> I could build a series of digital theremins underneath the board and
> infer from phase changes where the finger is. However essentially this
> algorithm (if I remember correctly) is patented by LeapFrog, they use
> it in their "touch-sensitive" (without switches) books and globes.
> 

Isn't this more or less a hobby or amusement project? If corporate and 
very qty limited ask them about a 'courtesy license'. Could mention 
their name in the paperwork in return.

Regards, Joerg

http://www.analogconsultants.com

Jonathan Kirwan wrote:

> Geeze, I don't see how Lewin can fail.  Ideas are flowing!  I need a
> PDP-11 in that form factor and I know that Lewin won't get to the
> PDP-11 before he gets that darned PDP-1 done, so.... anything to push

:) You'd be amazed how many people have said this.

The PDP-11 is much harder because peoples' expectations include media
support. It isn't enough simply to emulate the CPU, core and front
panel.

"larwe" <zwsdotcom@gmail.com> writes:

> Jonathan Kirwan wrote:
>
>> Geeze, I don't see how Lewin can fail.  Ideas are flowing!  I need a
>> PDP-11 in that form factor and I know that Lewin won't get to the
>> PDP-11 before he gets that darned PDP-1 done, so.... anything to push
>
> :) You'd be amazed how many people have said this.
>
> The PDP-11 is much harder because peoples' expectations include media
> support. It isn't enough simply to emulate the CPU, core and front
> panel.

Well they say that the MSP430 is already a PDP11 emulation... So it
might be easier than you think! :)


-- 

John Devereux

On 18 Jan 2006 12:10:34 -0800, "larwe" <zwsdotcom@gmail.com> wrote:

>Jonathan Kirwan wrote:
>
>> Geeze, I don't see how Lewin can fail.  Ideas are flowing!  I need a
>> PDP-11 in that form factor and I know that Lewin won't get to the
>> PDP-11 before he gets that darned PDP-1 done, so.... anything to push
>
>:) You'd be amazed how many people have said this.
>
>The PDP-11 is much harder because peoples' expectations include media
>support. It isn't enough simply to emulate the CPU, core and front
>panel.

Hey, I'd be cool with that much.  I bet I could figure out a way to
extend things for my own use.

But I also learned on the Bell Labs' Cardiac computer.  Moving a
little ladybug around and erasing and writing memory numbers in little
boxes as I run my own programs manually means that my standards are
pretty low and the PDP-1 is "high cotton" for me.  So I don't want to
get you off-track.

Jon

On Wed, 18 Jan 2006 21:06:57 +0000, John Devereux
<jdREMOVE@THISdevereux.me.uk> wrote:

>Well they say that the MSP430 is already a PDP11 emulation... So it
>might be easier than you think! :)

That's been said and it was my first impression, upon reading the
instruction set.  But then, reality set it.  See:

http://users.easystreet.com/jkirwan/new/msp430.html

For a comparison.

Jon

Jonathan Kirwan wrote:

> >The PDP-11 is much harder because peoples' expectations include media
> >support. It isn't enough simply to emulate the CPU, core and front
> >panel.
>
> Hey, I'd be cool with that much.  I bet I could figure out a way to
> extend things for my own use.

I can emulate a PDP-11/23 (the only PDP I ever personally owned) with
three switches and I think three lamps. It needs storage devices to get
software into the beast.. if I'm not going to emulate them then I might
as well not put any other electronics on the board at all.

On 18 Jan 2006 13:21:43 -0800, "larwe" <zwsdotcom@gmail.com> wrote:

>Jonathan Kirwan wrote:
>
>> >The PDP-11 is much harder because peoples' expectations include media
>> >support. It isn't enough simply to emulate the CPU, core and front
>> >panel.
>>
>> Hey, I'd be cool with that much.  I bet I could figure out a way to
>> extend things for my own use.
>
>I can emulate a PDP-11/23 (the only PDP I ever personally owned) with
>three switches and I think three lamps. It needs storage devices to get
>software into the beast.. if I'm not going to emulate them then I might
>as well not put any other electronics on the board at all.

Ah.  I was imagining a PDP-11/70 or PDP-11/45.  Particularly, since
you were already talking about lights and switches, my imagination did
not go over to the 11/23.  It just wouldn't make sense in the context.

I've loaded bootstraps more times than I'd like to remember and
programs as well, though the front panel of the /45 and /70.

Jon

> I'm trying to build the smallest possible tangible PDP-1 emulator. My
> ideal scenario would fit the circuit onto a double-sided 90 x 55mm PCB.

Spehro's suggestion is closest, so far, to what I had in mind.
http://www.larwe.com/pdpcard.gif shows a front panel layout that is
ALMOST final. The eight control switches are giving me trouble.

By the way, someone pointed out to me today that a KIM-1 emulator would
be another cool and easy thing to do on a similar hardware platform.
There are some very nice little surface-mount 7-segment LEDs, I am
giving it serious consideration. I won't have to modify substantially
the "RTOS" (really a strong word for it) I developed to run the PDP-1
emulator.

larwe wrote:

> Spehro's suggestion is closest, so far, to what I had in mind.
> http://www.larwe.com/pdpcard.gif shows a front panel layout that is
> ALMOST final. The eight control switches are giving me trouble.

Oh, one other thing: A citizen suggested yet another method, which is a
magnetic stylus and SOT23 Hall effect sensors as the "buttons". I
rather like this :)

"larwe" <zwsdotcom@gmail.com> a &#4294967295;crit dans le message de
news:1137644602.463004.40010@g49g2000cwa.googlegroups.com...
>
> larwe wrote:
>
> > Spehro's suggestion is closest, so far, to what I had in mind.
> > http://www.larwe.com/pdpcard.gif shows a front panel layout that is
> > ALMOST final. The eight control switches are giving me trouble.
>
> Oh, one other thing: A citizen suggested yet another method, which is a
> magnetic stylus and SOT23 Hall effect sensors as the "buttons". I
> rather like this :)
>

Or reed switches?


-- 
Thanks,
Fred.