The vstcm is a vector signal transceiver PCB which generates colour vector graphics to be displayed on an oscilloscope or vector monitor such as Amplifone, Wells Gardner WG6100, Hantarex MTRV and Electrohome G05, as used in Star Wars, Tempest, Gravitar, etc.

When used with a computer (Raspberry Pi, PC, ...) running AdvanceMAME, it can be used to play classic colour (and monochrome) vector arcade games, but it can also play certain games all by itself using various emulators. If you search for vstcm on a well-known video sharing site you can see the board in action.

(Haven't got a vector monitor or an oscilloscope? Make your own, it's not that hard! - see below).

For those who built a V2 of this board, a document is provided to convert the wiring to run with V3 software.

The original v.st was designed by Trammell Hudson for black & white games. Documentation for that version can be found here https://github.com/osresearch/vst and here https://trmm.net/V.st/

Compared to the original version, the new vstcm adds:

• RGB colour with different intensity levels
• 6502, Z80 and 6809 emulators which allows it to play games on its own without a Raspberry Pi or MAME
• A mini version of MAME for playing vector games on the Teensy without a Raspberry Pi
• An upgrade to the Teensy 4.1 for more power (eg >800Mhz as opposed to 120Mhz for the Teensy 3.2)
• Asteroids style test patterns in Red, Green & Blue to aid CRT convergence
• A configuration menu with settings stored on the built in SD card
• Programmable onboard control buttons
• Programmable IR remote control buttons
• Extra pots to control X & Y position (to complement the existing X & Y size pots)
• Several power supply options: either USB, or external 5V/9V/12V

The board was built with simplicity in mind using components that are easy to find, and easy to solder so that anyone can build one.

Currently, the board can work in either of two ways:

• connected to a Raspberry Pi running MAME. The programme code for this option is a development of that which was provided with the original version of the v.st, with modifications made by "Swapfile" (Github user) to interface with AdvanceMAME, and then further modifications made by myself in order to add the new functionality specific to the vstcm, followed by extensive optimisation by fcawth (cf his fork of this project). There is scope for further improvement (see the wiki for this project in the link above), and it is hoped that the publication on github will encourage contributions to develop this as a relatively cheap and easy solution for the vector arcade / vector graphics community.
• on its own, running a 6502, Z80 or 6809 emulator, and with the original game ROM files stored on the SD card of the Teensy. So far, Battlezone, Asteroids and Donkey Kong work with this, but it shouldn't be too much trouble to get others working. Sound and external controls have not been properly implemented as yet (please feel free to contribute the necessary mods to the code...). See instructions below for how to get this to work.

For those interested in seeing how things got to this point, the inital development of the PCB was documented with plenty of pictures (in French, but use Google Translate if required) here : https://www.gamoover.net/Forums/index.php?topic=43469.0 (from page 5) and also shows previous work on building vector arcade HV boards, an Amplifone deflection reproduction, an Asteroids game PCB reproduction, a bit of yoke rewinding, etc.

If you want to get in touch to ask questions, or contribute, I can be contacted at: [email protected] or on Github (user english1234), Gamoover (english2), UKVAC (english2), KLOV (english2), as well as via the various vector graphics/Vectrex forums on Facebook.

A dedicated vstcm web page can be found here: https://robinchampion.com/vst_colour_mod.htm

Thread on KLOV: https://forums.arcade-museum.com/threads/announcing-the-vstcm-colour-vector-generator.505940/

Thread on UKVAC: https://www.ukvac.com/forum/announcing-the-vstcm-colour-vector-generator_topic388998_page1.html

A ZIP file is in the Gerbers directory. This can be uploaded to your PCB manufacturer of choice. It's a 2 sided 10cm x 10cm board so should be extremely cheap (JLPCB charged less than 5€ / $5 + shipping for 10 pieces in May 2022).

The BOM is in a dedicated folder and has Mouser references for many parts at the right hand side.

• IC2: You need to choose if you are going to use an external supply or not and if so what voltage to use (5V, 9V or 12V). Recom makes these parts, but so do Traco and there may be other brands. Make sure there is a D (for double) at the end of the model number which generates +/- voltages, rather than the S (single) version. See power options below.
• The Molex parts are not strictly necessary, you may prefer something different or simply to solder wires directly to the holes in the PCB.
• U5: See power options below. I have also used a 7805 as a direct replacement with a small heatsink on it, which gets quite warm but hasn't burnt out as yet.
• optional IR remote: I really recommend this if you are putting the board inside a cabinet - see "IR remote programmable control buttons" below.

I would recommend socketing everything on the board (Teensy, DACs, Op Amps) so that they can be swapped out if better choices are found in the future.

Make sure you order short resistors, space for them on the board is tight.

The PCB can be powered in several ways:

1/ power the whole thing via USB from a Raspberry Pi: This requires a short good quality USB cable to work reliably. Make sure the Pi has at least a 3A supply.

2/ power the Teensy via USB from a Raspberry Pi, and use a separate external supply (such as a wall wart) for the DACs and Op Amps.

3 & 4/ power the whole thing via an external supply which can be 9V or 12V (not 5V): this requires adding a LM2940T-5.0 regulator at U5 along with it's associated caps at C19 & C20, as well as cutting a link on the Teensy to ensure that it doesn't receive conflicting power from both the USB and the external supply. The RB-xx12D needs to be either a 9V or 12V model depending on the voltage of the external supply. A 5V supply won't work as the LM2940 requires over 6V to function according to its datasheet.

5/ If you already have a perfectly regulated and smooth 12V supply, then you can connect it to J7.

The choice is really just a matter of what you have on hand. It makes no difference what vector CRT you have, as the output voltages of the PCB are the same whatever you use to power it. If you're connecting to an existing arcade machine, then chances are you have a +/-12V supply coming out of the power brick. Otherwise, many people have a box of old "wall wart" 5V (or 9V or 12V) adapters which will work fine: either fit a barrel connector to the PCB input or chop the connector off the end of the power supply and solder the 2 wires directly to the board (check with a multimeter first which is positive and which is ground).

The easiest option is to use a 5V (option 2) as the LM2940 is not required, and you don't need to cut the link on the Teensy to separate USB and external power.