does anybody remember who was building generic front panels - - long response

From: woodelf <bfranchuk_at_jetnet.ab.ca>
Date: Wed Feb 2 02:40:37 2005

Gooijen H wrote:

>An other difficult part are indeed the switches.
>First, I must say that I *never* had the intention to make a 1:1 replica of
>the
>frontpanel. My museum is already quite full as it is (with even more to
>come)!
>I searched for paddle type switches, normal and spring-loaded. Not easy, but
>the ones I found can still be ordered, but they are indeed rather small: the
>lebgth of the paddle is approx 12-15 mm (IIRC) and the width is 10 mm. If
>you
>have thick fingers the size is really small.
>The size of the switches determined the total length of the frontpanel which
>is still 36 cm. The height is then set by proportion compared to the real
>frontpanel.
>
>
So what are the part numbers of the switches you used?


>As Ethan said it: you must make the size of the switches and the frontpanel
>proprotional to eachother. If you want the frontpanel to be as close to the
>original as possible it must be 19" wide. Small switches is definitely not
>what you want in that case!
>The ones used on the FP6120 look bigger than the C&K ones that I used, but
>the finishing touch is of course to get them in the correct color.
>More work, but I said it on my website: the end result is very depending on
>the effort and time you spend on the frontpanel.
>
>
In my case I have *NO* tool s of any kind or the practical knowlage
of the metalworking
to be done so I my case I have get other people to do the work so front
panel express is
most likely the way I will go.

>Rich mentioned the price tag. He is correct that you must do the math.
>The switches are easily costing $4 a piece, and for a PDP-11 or -8
>frontpanel
>just the switches will set you back some $80 to $100.
>
>
$4??? I have been looking at switches and they range from 25 cents (
surplus )
to $25+ each and you still have the display to worry about. Also it
seems that
you have more display options than just leds but that is more $$$ yet.


>The problem with designing a PCB for the LED's and switches is not the
>electronic part, as said in the beginning of this e-mail :~) The design is
>simple and straight-forward *if* you have the dimensions of the switches
>that
>are going to be used. Making a frontpanel PCB is only useful if you know
>before how many are going to be wanted (and bought!) *and* you know for sure
>that the required amount and type of switches is available.
>Note that you *still* need (metal) work before you start soldering the
>switches
>to make sure that they line up perfectly. If you just solder the switches in
>the PCB you will see that you could get them lined up better. I guess that
>you get solve that by soldering only *one* pin of all the switches, and then
>line them up using the soldering iron and three hands :~)
>
>
In my case I belive PCB's are a better option than wire wrapping. In my
case I have more
time than skill so doing computer work is easy as compared to mechanical
stuff.
By using CPLD's I hope to get the cpu and memory and I/O on one board and
just have the front panel I/O come out. The only real problem with me doing
a hardware version of the 8 is the complex hardware for extended
memory and
hardware details that you don't expect. Since the CPLD's are
reprogramable I could
do almost any small computer that is not micro-programmed or have lots
of registers.
 

>Same story goes for the LEDs, but depending their visibility (when they are
>off)
>you get get away with a less than perfect alignment ...
>
>
Has anybody tried using the white leds for displays?

>One thing you must consider -- and I forgot that in my construction!!
>The frontpanel plate will have some distance to the plate where the switches
>are
>mounted on - or if you like: the PCB where they are soldered on.
>Keep that distance in mind when you solder the LEDs (or lamps). Try to get
>the
>
The other chicken and the egg problem is knowing just what to buy, since you
practicaly have to build it first to get what ideas and parts you need.

> thanks for the nice feedback on my project,
>
>- Henk, PA8PDP.
>
>
Received on Wed Feb 02 2005 - 02:40:37 GMT