Alvin G PCA-003 VFD Display Modules

[Richard Scales]

I was wondering whether anyone has had any success talking to the Alvin G PCA-003 boards that are available: https://www.pinballspareparts.com.au/electronics/displays/pca-003.html
I would be interested to hear from anyone that has managed to talk to one or who might be able to provide any insight into how their interface works.

I have a few coming my way and would like to see if I can make them talk somehow.

Any pointers to information about interfacing requirements and protocols etc would be most welcome.

[Keith Moore]

Richard, I have not yet done it, but I do plan to at some time. I got a few of these for various reasons (demo/display, etc.). I assume you have the detailed data / pinball instruction sheet like I do. If not, let me know.  

https://www.dropbox.com/s/bltgd4w4o9gonuy/Alvin_G_Display.zip?dl=0

My chops aren't good enough to just whip out the electronics to drive these, but I was planning on making a computer that does this eventually. It is an IEEE 8255 interface. I should be able to do it with an arduino. 

[Richard Scales]

That's exactly what I was thinking off - thank you for the diagrams - I had nothing on them - certainly not the detailed data / pinball instruction sheet and would of course be grateful for any information.

The PSU requirements look like a  good place to start.

Kind regards

Richard

[Nixcited delighted]

On Wednesday, 18 September 2019 04:11:26 UTC+1, Richard Scales wrote:

I was wondering whether anyone has had any success talking to the Alvin G PCA-003 boards that are available: https://www.pinballspareparts.com.au/electronics/displays/pca-003.html

 

Hi Richard,

Apologies for the delayed response - my ISP changed servers and outgoing mail has stopped.

I posted links to schematics I scanned from a pinball user manual. A zip is in my Dropbox at https://www.dropbox.com/s/bltgd4w4o9gonuy/Alvin_G_Display.zip?dl=0 - I think someone already pointed you at these.

I sent a display to Andrew Jardine, who is quite good with these VFD displays and pinball and he was going to see if he could fire one up, but I suppose he’s got bogged down in real life when he really should be fixing up old tech. for me. He's in this group, so he may comment. For myself I’ve not started with the displays either, so I suppose I am just as guilty.

I was really annoyed with the way my 10 displays were packed. Layered loose side by side in bubble wrap and they’d all been moving about. The large cap on the back was ripped off half of them and one display had broken glass, so it’s useless. The guy said he’d packed them well and wasn’t interested in my complaint.

Rearguards,

John S 

[Richard Scales]

Disappointing news about the packing. Mine are being transported mostly by hand from Australia so hopefully they'll each make it in one piece! I look forward to having a go at driving them. I can see that interfacing then to something like an Arduino looks easy enough. I suspect it's more a matter of the data required to drive them.
Richard

[Mac Doktor]

On Sep 19, 2019, at 5:37 AM, Nixcited delighted <j...@jsdesign.co.uk> wrote:

I was really annoyed with the way my 10 displays were packed. Layered loose side by side in bubble wrap and they’d all been moving about. The large cap on the back was ripped off half of them and one display had broken glass, so it’s useless. The guy said he’d packed them well and wasn’t interested in my complaint.

I take pictures of obviously damaged boxes and/or contents at the first opportunity. It gives me some ammo to use.

Recently I received an HP frequency counter (with Nixies, of course) and the box was so beat up that the people at the post office recommended that I send it back. Knowing how rugged HP stuff is I took a chance on it—after taking several pictures of it sitting on the counter in front of the grinning clerk. It works fine.

A friend of mine bought a computer monitor years ago—19" CRT—and when she heard the UPS van pull up she went to the door. She got there just in time to stop the UPS guy from leaving. The box wasn't a cube anymore, it was a ball. All eight corners mashed in. It made all kinds of jangling sounds when moved. It left with the UPS van.

Terry Bowman, KA4HJH
"The Mac Doctor"

[Keith Moore]

So we all have to swear on a pinky-pact that if any one of us lights one of these up, they share the details with everyone else here. I think these displays are the ginchiest. I don't normally do FVDs so I am planning to use these as my learning opportunity. I do plan to work on these, but as was mentioned in another comment here, life is in  the way for a while.  That's my lame temporary excuse. It'll pop up to the top in a while.   But let's all promise that we will share when we get these going. They really are nice, versatile displays. 

On Tuesday, September 17, 2019 at 11:11:26 PM UTC-4, Richard Scales wrote:

[GastonP]

Actually, the 8255 and an LS273, both through HV buffers, drive the segments.Ports A and B of the 8255 drive the "upper" VFD anodes (+47V) while Port C and the LS273 drive the "lower" VFD anodes (+47V).

The TL5812 drives the digit grids (one per digit) through a separate serial shift register interface.

It's a classic configuration for a multiplexed display, that can be easily controlled by any modern microcontroller with 16 free pins without recurring to specialized hardware. Just plain old parallel interface for the segments plus a little bit-banging for the digits. If one wants to use a processor with less free pins, it can be done too, but the complexity grows.

I just ordered a couple of this boards and am crossing my fingers...

[Richard Scales]

That sounds promising - what would be your platform of choice? I can see that something like Arduino Mega or a Teensy would have the required i/o.

I have no experience of doing anything with a multiplexed display,  it all seems like magic to me!

[GastonP]

Well, I just received my display boards.

     I will be lucky if I can make 2 out of the 4 boards I got. I must be fair and say that I ordered just 2 and the vendor sent me 4, but the packing was... inappropriate. All of the boards were piled up one on top of the other without any kind of separator, one layer of thin bubble wrap on the bottom of the box, 2 or 3 on the top and that was it. Only one board has both displays with vacuum in them (one of which was chipped in one of its ends), which is not the same as saying that they are both working. Of the remaining three, two had one of the displays without vacuum and the last of them had one of the displays totally mashed. There were glass pieces all over the place.

It makes me remind of the horror stories about the sale of NL7971s by Poly-Pack (IIRC).

I have a strong suspicion that a couple of the displays were already damaged before being packed. Besides, all boards show signs of attempted repairs (mostly around the electrolytic caps) and spewed electrolyte, but again to be fair the boards are being sold as untested and coming from an bulk warehouse stock buy. We all know how wide is the definition of untested.

Anyway, I plan to clean up the mess, apply 5Vcc to the TTL and HV power supply lines, tie a microcontroller kit and check the status of the logic and driver chips before deciding which boards become donors.

Regarding to which platform I would use... I have several NodeMCU ESP32 sitting in a box which I think with a little struggling or worst case adding some glue logic can be used. WiFi configuration and NTP syncronization would be cool. If this plan does not work, then my fallback is Arduino nano as I also have several sitting in a box next to the NodeMCUs :).

[Richard Scales]

i just got hands on a box of 10 - many have loose caps, one has a chipped display the rest look fine - but time will tell, I still have to get them home to the UK - I look forward to seeing how you get on!

[Richard Scales]

Happy New Year everyone. I was just wondering if anyone had made any progress with any of these displays yet?

[Keith Moore]

Not yet, Richard.   I do hope to later in the year. I have 2 other projects in front of this one still. Stuff keeps bumping up in front of this one but I do still plan to play with it this year.

- Keith  

[Richard Scales]

I know how it can be - I thought I was on top of everything and then another display device pops up which I just cant help investigating - currently Sperry / Babcock SP-101's!

-Richard