Class 365 PBC Unit and PIS system

[ac6000cw]

Looking at the photo in post #141, that track looks broken or deliberately cut (looks like it's got bare copper bits on either side of the break, where the green solder resist covering has gone). The brown patches are likely old rosin-based solder flux residue. Maybe someone has replaced one of the chips and damaged the track in the process. To get a proper look at the damage, you'd need to find a suitable flux-remover solvent and a small stiff brush, or you could try carefully scraping the area around it with e.g. the point of a craft knife.

At least it's all large through-hole components and wide PCB tracks so you don't need a microscope to see them!

 

[365 Networker]

An interesting video showing the PIS system on the underground 1986 prototype stock - these I believe were built by BREL, so perhaps use an earlier version of the JASMIN system used in the networkers.

 

[365 Networker]

There aren't any updates currently as I'm just arranging a day when I can meet up with my friend to get them.

If and when you acquire the EPROMs, do you know how to retrieve the data? You might also need to use a virtual machine to view the data - the files could be in a format not supported on modern systems.

 

[WMasterJedi]

If and when you acquire the EPROMs, do you know how to retrieve the data? You might also need to use a virtual machine to view the data - the files could be in a format not supported on modern systems.

I can confirm I will be getting them but I’m unsure when as both me and my friend are busy but I’m assuming some time in the summer holidays.

 

[WMasterJedi]

Progress on the destination board and controller has kind of stopped for now as I’m happy with how it is currently so I’m moving my focus on to reverse engineering one of the internal dot matrix boards.

 

[365 Networker]

Progress on the destination board and controller has kind of stopped for now as I’m happy with how it is currently so I’m moving my focus on to reverse engineering one of the internal dot matrix boards.

It would be interesting to see if you could get the internal PIS dot matrix to display messages - whether that be calling patterns or perhaps custom messages (I did see someone online had programmed an old 465 display for custom messages).

 

[WMasterJedi]

I have 3 internal dot matrix screens in total 2 that look identical and the other which is the one that would sit above the cab door.

Now, I have only ever looked inside 2 of them, the one that sits above the cab door and one of the identical ones.
Both of them had the PCB that included latched shift registers and the dot matrix panels as well as 3 other PCBs for power, logic and another that was for general stuff and doesn’t have any processing (microcontrollers) or any of that on it.

I already had a suspicion of this before opening the other identical screen as it only had one small connector but this suspicion was confirmed once I looked inside, there isn’t any logic or even power board instead along with the screen PCB there was a singular PCB named “Slave Isolation”.

This is because the identical screen that does have a logic and power board is the master and not only does it display stuff on its own screen but also sends the signals to display stuff on the slave screen.

 

[WMasterJedi]

It would be interesting to see if you could get the internal PIS dot matrix to display messages - whether that be calling patterns or perhaps custom messages (I did see someone online had programmed an old 465 display for custom messages).

That is such a coincidence for what I just sent!

 

[WMasterJedi]

I have 3 internal dot matrix screens in total 2 that look identical and the other which is the one that would sit above the cab door.

Now, I have only ever looked inside 2 of them, the one that sits above the cab door and one of the identical ones.
Both of them had the PCB that included latched shift registers and the dot matrix panels as well as 3 other PCBs for power, logic and another that was for general stuff and doesn’t have any processing (microcontrollers) or any of that on it.

I already had a suspicion of this before opening the other identical screen as it only had one small connector but this suspicion was confirmed once I looked inside, there isn’t any logic or even power board instead along with the screen PCB there was a singular PCB named “Slave Isolation”.View attachment 159735
View attachment 159736
This is because the identical screen that does have a logic and power board is the master and not only does it display stuff on its own screen but also sends the signals to display stuff on the slave screen.

What is also good is that because this board gets the signals to display stuff externally, once I am done reverse engineering it, which is going very well, I will be able to show custom messages on it without even having to open it up!

 

[WMasterJedi]

It would be interesting to see if you could get the internal PIS dot matrix to display messages - whether that be calling patterns or perhaps custom messages (I did see someone online had programmed an old 465 display for custom messages).

When I do start progress on the controller again if I can properly get it into master I may be able to show actual messages but for now custom is still great!

 

[365 Networker]

When I do start progress on the controller again if I can properly get it into master I may be able to show actual messages but for now custom is still great!

Absolutely - I found this online https://forum.arduino.cc/t/led-matrix-online-editor/334746 - it may be of some use to you.

 

[WMasterJedi]

Unfortunately that won't work as the boards use a different way of doing things.

 

[WMasterJedi]

I have removed the dot matrix boards from the metal and they look fabulous!

 

[WMasterJedi]

I have got the internal display to partially work with an arduino!

 

[365 Networker]

I have got the internal display to partially work with an arduino!

Excellent - presumably you should be able to programme text to appear.

 

[WMasterJedi]

Excellent - presumably you should be able to programme text to appear.

Exactly, I just need to connect clock and data for the shift registers to my arduino which will then be able to send bits to choose which LEDs to have lit then the final 8 bits go to another shift register which selects which row to light.

Currently I need to power “output enable” manually as I have not figured out what bits to send to do that manually also the same for the row select, it works but I have not figured out how to do it properly without just doing it on accident.

Sometimes some bits come through as 0 when it should be 1 and 1 when it should be 0 this is due to me not having the correct connector so sometimes things like that happens and the electricity doesn’t get through properly (this also doesn’t help with the line select as that is quite precise)

 

[WMasterJedi]

I know how it works, but it’s just writing the code and when and how to send the bits in a way that will be perfect.

 

[WMasterJedi]

Update!
I am now somewhat reliably able to send bits to the shift registers and get them to show.

Couple of problems due to a non proper connection causing there to be a 0 where there should be a 1 or a 1 where there should be a 0, very minor though.

I am also able to change 3 bits in the first 8 bits to select which row to display.

 

[WMasterJedi]

Update!
I am now somewhat reliably able to send bits to the shift registers and get them to show.

Couple of problems due to a non proper connection causing there to be a 0 where there should be a 1 or a 1 where there should be a 0, very minor though.

I am also able to change 3 bits in the first 8 bits to select which row to display.

A brilliant success!

I have connected my arduino to the 4 pin plug that is used to transmit data to the screen and by writing some code for the clock and data lines I have been able to make a little test where the screen shows HI!

 

[365 Networker]

A brilliant success!

I have connected my arduino to the 4 pin plug that is used to transmit data to the screen and by writing some code for the clock and data lines I have been able to make a little test where the screen shows HI!

Good work!

 

[WMasterJedi]

I have successfully recreated the letter a in the original font using images from when I had it connected to the original logic board as references.

Not only that but I have been able to make it scroll!

 

[WMasterJedi]

I have successfully recreated the letter a in the original font using images from when I had it connected to the original logic board as references.

Not only that but I have been able to make it scroll!

Also please ignore the flicker. This is just the annoying thing that happens when you try to record/photograph dot matrix screens.

In real life there is very slight flicker due to my code not being super optimised but far less than what’s on camera and very unnoticeable.

 

[WMasterJedi]

I mentioned in a previous post that I'm currently moving my focus to the internal dot matrix screens but I am kind of moving between that and the main destination board.

I discovered why the two indicator lights on the front of the main display were not working, as expected, the 12V 5W Halogen bulbs had burnt out. Luckily the type of bulb that it uses are readily available to buy and I have found some on Amazon which are also 12V 5W but also look absolutely identical and are the same size.

Handily the bulbs are in little sockets which means replacing them will be simple!