Power to the Revelators !

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First, my good old (t)rusty PowerColor TNT2/M64 card may have got color, but it ain't got the power, at least not the +5V power on pin #9 of the VGA socket needed to drive the Revelators. Even worse, my in-laws' new PowerColor PowerGene Geforce MX/200 shows the same non-feature. Looks like the board designers at Powercolor (or whereever they get their boards from...) at least try to be consistent in their designs.

Thus, I heated up my soldering iron and tried help my poor Revelator' hunger for power...

1. Find out how it should have been and fix it

For the details, I've made up some separate pages, one for the power sources and a few others (links below) for how to feed the power to the Revelators. Just follow the links.



2. Find some other power source

A PC with a few 100 Watts of power supply hanging around somewhere close to you, it shouldn't be too hard to find 5Volts for ~100mA somewhere. In fact, there are several choices (click on the images for details):

  • USB port : desgined to supply peripherals with data and power connections, a perfect choice (unless all your USB ports are already occupied by mouse, keyboard, joystick, scanner, cam...)

USB standard wire colours are : red/+5V, black/GND, green+white/data
  • Game port : also provides power – if it can drive a force-feedback, it can also drive the Revelators. If you still use it for your joystick, you can easily build a pass-through adaptor.

A gameport dongle consists of a male and female connector soldered back-to-back
  • DIY power port : there are usually lots of spare disk power connectors providing 5V and 12V inside your PC (or at least some cheap Y-splitters), so why not take them to the backplane for something useful ?

  • Other choices : PS/2 keyboard and mouse connectors also provide 5V supply, but sometimes with sensitive melting fuses somewhere on the mainboard, and the mini-DIN connectors to build a pass-through may be hard to get. Some parallel and serial port devices also draw power from their ports, but this is very limited. Better choose one of the three solutions above.

3. Take it to the Revelators

Having made up your mind about the power source, here comes the next question. This, of course, depends – on availability of parts, and inclination to salvage the splitter-cable that comes with the Revelators. In addition, there is also chance to solve the nasty DDC problems by not connecting the VGA pin 12 (the Revelator L/R control, but originally used for DDC communication between PC and p&p monitors) Some possibilities :

  • Splicing the supply into the thin cable to the mini DIN3-connector of the Revelator adaptor, either just cutting the whole cable and re-connecting the other two wires, or just fiddling the power wire out of the bunch. No extra parts (except some isolation tape), no DDC fix, messing with the original adaptor.

  • Build a DIN3-pass-through adaptor. Needs just a male and female mini-DIN3 connector, which may be difficult to find, and some cable, but leaves the original adaptor untouched. Sorry, no DDC fix here either.

  • Build your own adaptor from scratch. VGA connectors should be easy to find, but the mini-DIN-3 socket for the glasses may be a problem. Needs a few parts, but you know what you got (DDC fix included). If you're brave and salvage the Revelator adaptor, you can even save some parts (especially the mini-DIN-3 socket) and soldering work.

  • Build a VGA splitter ('T-Bone',as I call it). Needs just VGA connectors, with all video going to socket A for the monitor (except pin12 for the DDC fix), all Revelator to socket B for the original adaptor to plug in. In fact my personal favourite, since you can also fork Vsync to socket B, which means you could also connect a DIY page-flip circuit and get rid of any IRQ problems with the Revelator control. Stay tuned for that one, I'll get it online ASAP.

4. A little note about cables

Note that in some cases it is really easier to salvage custom cables; however, there is hardly any need to pay the full price of a brand new cable (unless your only resort is mail-order). With a little luck, in most computer/electronics shops (and even supermarkets) you may find some surplus corner where you can get outdated (like old Voodoo2 loop cables) or unpacked cables for little money. Mostly, one cable will also be enough for two adaptors, so could share the costs with a friend with the same problem. Strange enough, the better (and more expensive) cables get their connectors cast in soft plastic, while the some ultra-cheap cables you occasionally find at computer trade shows are in fact homebrewer's dream (see picture) :
Some length of cable, with snap-lock (rarely screwed) plastic shells on neatly soldered connectors, with a set of long thumbscrews, at a price for which you would hardly get the plugs and shells in an electronic parts store.