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PDP-8/e Front panel light color(s)?

C

Crawford

Experienced Member
Joined
Oct 21, 2008
Messages
275
Location
Maryland
Folks,

Can anyone tell me the color (colour) of the front panel lights on a PDP-8/e?

Did they use the same color for memory address, data and the 'run' light?

(all the net pictures are with the system off or blurry).

Thanks,
Crawford
 
8/e Lamps

8/e Lamps

Crawford,

The originals were lamps (incandescent). At some point, some lamps were replaced with amber leds. When we got our machine, it had been converted to amber leds. I converted it back to lamps. When I put the front panel back on, I'll send you a photo with the lamps lit.

Actually, there was just a discussion recently on lamps/leds on alt.sys.pdp8. There I learned that the lamps I used are not the correct brightness. I used lamps my father had for the KA10, which are rated for a higher voltage than the KC8-EA applies to them. Still looks OK to me though.

Here: http://www.frappr.com/pdp8owners/map there is my machine on a table next to a VT52, and another guy's machine in a different picture, powered up. The incandescent lamps have a yellowish cast. His might be the amber leds, mine just aren't bright enough.

Lou
 
PDP-8 front panel lights

PDP-8 front panel lights

Lou,

Thanks.

From a 'historical correctness' standpoint it looks like incandescent lights are the right way to go. However, wouldn't LED's work better (while running) to see what's going on? LED's would have better response time, and show a change, where the incandescent, pulsed quickly would still be lit? I realize that most of the time, the lights are useful in 'steady state'/stopped mode.

-Crawford
 
Hi,

I have an "Industrial 8" (8/E with red and blue switches). It has incandescent bulbs - not LEDs - behind the FP. Visibility is good.

cheers

John
 
miles said:
Hi,

I have an "Industrial 8" (8/E with red and blue switches). It has incandescent bulbs - not LEDs - behind the FP. Visibility is good.

cheers

John
Click to expand...

That sounds interesting, could you perhaps share a picture? I _think_ I know how they look, but I'd like to learn more about the different versions of PDP-8's made.

Cheers,
Pontus.
 
Industrial 8 Pictures

Industrial 8 Pictures

John,

Yes, please post pictures of the Industrial 8! Red and blue sounds like it might look less 1970's than the 'earth tone' red/yellow/orange of the other DEC equipment... reminds me of long hair, shag carpet and advocado-colored kitchen appliances.

-Crawford
 
I still prefer lamps over LEDs. I know the LEDs will last longer, but the lamps look nicer.
I also prefer the looks of the 8i over the 8e. It's so nice not to have to switch between
selections. I believe the 8i uses those same bulbs that the KA-10 used. Very hard to find.
Tim Radde
 
Hi Folks,

Here is a photo of the beast. I'll make some better photos in daylight and post them on my web. Meanwhile enjoy ....

cheers

John
 

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miles said:
Hi Folks,

Here is a photo of the beast. I'll make some better photos in daylight and post them on my web. Meanwhile enjoy ....

cheers

John
Click to expand...

Thanks, I haven't seen that version before :) pretty cool looking. I have some pictures at home of other variants. Maybe I should put them on the web.
 
I was thinking about this:

IMG_2783.JPG


But it turns out it is actually based on the intel 8008, who knew :)
 
Pontus,

What machine is that????? I have never seen anything like that!! You say it is based on the 8008, which I can believe because the switch register appears to be broken into an 8 bit portion and six bit portion. What other info do you have on this thing?

Lou
 
Lou - N2MIY said:
Pontus,

What machine is that????? I have never seen anything like that!! You say it is based on the 8008, which I can believe because the switch register appears to be broken into an 8 bit portion and six bit portion. What other info do you have on this thing?

Lou
Click to expand...

I don't know much about it. The picture is taken from a brochure that came with my PDP-8/e. Apparently it is a really simple system meant for industrial applications called the "MPS Microprocessor Series" and one of Digitals first uses of micros. It consists of three quad height flip chips: CPU, RAM and ROM. And a fourth single height flip chip called the "external event detector". If you scroll down the manual there is also a pretty nifty ROM programmer.

http://www.bitsavers.org/pdf/dec/mps/


A quick search on the classiccmp mailing list shows that one was sold on ebay in 2002, not very common system I believe.
 
I just read the manual on Bitsavers, and had a look at the print set (see the 8008 there!). This is basically a more intelligent version of the PDP-16. The 16 was for industrial control and relied very heavily on the 8 to operate. This unit only relies on the 8 for program compilation. The module numbering is interspersed with the module numbers for the 16. It must have come from the same group. Thanks for showing us this!

Lou
 
8008 from DEC?

8008 from DEC?

Pontus,

Is that just a picture, or have you seen the real thing? It's very 'mod' ... more '60s than '70s. (Spock just called and he wants his computer back!)

I still can't see the picture that John M. posted..

How about we start a blinkenlights/Front Panel gallery? (when men were nerds and computers had lights and switches)

-Crawford
 
Lou - N2MIY said:
The module numbering is interspersed with the module numbers for the 16. It must have come from the same group. Thanks for showing us this!

Lou
Click to expand...

Glad you like it :) I should read up on the PDP-14 and PDP-16, but they seem rather booring.

Crawford said:
Pontus,

Is that just a picture, or have you seen the real thing? It's very 'mod' ... more '60s than '70s. (Spock just called and he wants his computer back!)

I still can't see the picture that John M. posted..

How about we start a blinkenlights/Front Panel gallery? (when men were nerds and computers had lights and switches)

-Crawford
Click to expand...

That is just a picture, never seen it :) I imagine Spock would scoff at our tech, but the design is right up his alley.

Don't know why you can't see John's picture, it works fine for me.

It would be fun with a front panel gallery :) There are more variants than you think.
 
I think I got the 14 and 16 mixed up earlier. It was the 14 that was really dependant on the 8. The 16 was quite a bit more stand alone. This MPS looks like a microprocessor based 16 (and my comment about the card numbers still appears to be true.) Unlike a 16, this thing has lights and switches

So how do we go about making a front panel gallery?

Lou
 
Lou - N2MIY said:
I think I got the 14 and 16 mixed up earlier. It was the 14 that was really dependant on the 8. The 16 was quite a bit more stand alone. This MPS looks like a microprocessor based 16 (and my comment about the card numbers still appears to be true.) Unlike a 16, this thing has lights and switches

So how do we go about making a front panel gallery?

Lou
Click to expand...

Well, the easy part is to get some web hosting and set up a simple page, nothing fancy necessary. The tricky part is getting the pictures (I have a few on my hard drive) and the rights to use them. I would really like to show up the odd ones, and then you really need the consent of the author of the pictures.

Anyway, here is a nice writeup on front panels (with pics, sort of):

http://www.quadibloc.com/comp/panint.htm
 
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