swap-file/open-dvg

open-dvg

This is a heavily modified version of the v.st vector board that targets installation in arcade cabinets with an Electrohome GO5-802 / 805 monitor.

It uses the same serial protocol as the USB-DVG, meaning you can use standard builds of AdvanceMAME with it.

Protocol Documentation Here: https://github.com/amadvance/advancemame/blob/master/advance/osd/dvg.c

Hardware and software is currently in BETA! The PCB is very out of date; it requires a lot of hand rework and the Teensy 4.1 hangs off the end of it. I need to pick some different faster DACs and make a new circuit board.

The software is not heavily optimized either; consider it a proof of concept. Buy a USB-DVG if you want something that works out of the box.

The original project which targets Vectrex monitors can be found here: https://github.com/osresearch/vst

Step 1: Building the hardware

The circuit board design in this repo is not up to date. See Op-Amp and DAC reference adjustment notes here:
osresearch/vst#25 (comment)

To get the speed we need to use both SPI ports to output to separate X and Y DACs at the same time. Cut the clk and data traces going to the old XY DAC and wire it to SPI1 with a pair of jumpers. Then route the old Y op amp input to the WZ DAC's unused output. See photos in the modifications folder.

Step 2: Flashing the Firmware

Make sure you have Visual Studio Code with PlatformIO installed.

Step 3: Make sure you get a test pattern to display

Hook up your vst board to your monitor and ensure you see a suitable test pattern displayed.

Step 4: Compile AdvanceMAME

http://www.advancemame.it/doc-build