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Quantel DPB-7001 Paintbox MAME Emulator

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Bumping this to bring you all up to date:

Work on the emulator has been progressing of late, there was a period of little activity due to TheMogMiner having other commitments and a technical road-block which has now been worked around so he is back making progress! So lets talk about that now...

So of course the Paintbox doesn't just consist of the DPB itself it is made up of various parts which also all need to be emulated if we're going to do this properly. These parts are:

DPB-7001 - The main machine of course

Tablet - The tablet operated by the user. This is made up of the TDS tablet electronics and a Quantel interface :

TDS Tablet electronics (using 8681 CPU)
This processes the analog data from the tablet pickup coils and converts them into serial data which is sent to the ID20 interface.

Quantel ID20 TDS Tablet interface (using 6803 CPU)
The ID20 interface lives inside the tablet enclosure and connects to the original TDS hardware, it takes the serial data from the tablet and merges in the RAT buttons, pen pressure data and the keyboard then outputs packets of data to the DPB over an RS422 serial link. This means there is only one single link between the tablet and the DPB allowing the DPB to sit in a remote rack. So the keyboard and RAT both plug into the back of the tablet.

Keyboard - (using 8039 CPU)
The keyboard is a simple affair and simply outputs ASCII codes over RS232 to the ID20 interface.

All of these peripherals have to be included into the emulator. It was during the emulation of the TDS Tablet controller there were issues working out the analog data from the RF coils that get sent to an ADC so the TDS interface can work out where the pen is. At the moment to get the project moving it was decided to simply push the right serial data out of the TDS part into the ID20 interface. It means we have a working tablet but it's not an actual emulation of the original TDS one.

Once these elements were put together we then had a user input into the DPB emulator and we can interact with it.

These images here are the current status of the emulator, to explain what your seeing... The image is broken into 4 quadrants, the top left is the VDU diagnostics video output which is from the Computer part of the DPB. The top right is Framestore 2 with an additional overlay which shows the brush store in the bottom left of that, bottom left is Framestore 1. With the bottom right being a visual representation of some of the internal registers over the video period.

So to be clear this is not video output from the DPB yet!

The main video output is normally generated by the Combiner card, it takes data from the framestores and creates the final video data which is then passed to the Output Proc card which generates the actual analog video output card. Combiner also adds on the cursor and stencil overlay if it's turned on by the user.

Right now the combiner is not emulated at all which is why we are looking at the data stored in the framestores as just a big bitmap.

So in the images below we can see we have the paintbox palette visible:

Of course there is still a LOT of work to do, but it is excellent progress! I will post up more as it happens.


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