If you already have a laptop computer, just take the output, run through NTSC to VGA converter, and feed to Virtual Vision glasses. See review of head mounted displays for description of VV glasses.
additional notes on low cost wearcomp: you can change the regulator in the VGA to NTSC converter to improve efficiency and extend battery life by a factor of typically more than two (e.g. typically more than twice as efficient). See wearhow, in particular, see node17.html and ignore wearcomp6/wearcomp7 heading (e.g. if you're building wearcomp5, this page is also very relevant).
You can improve on the VV glasses by getting rid of the big
control box, and just driving the glasses directly as follows
Here's what we have looking at the male connector, facing the prongs (a mini 9 pin connector, just like the connector used on the PT/1 glasses described in review of head mounted displays and also just like the power connector of the ViA Flex PC, but despite its ubiquity it's hard to find these connectors and they fail easily):
c s bl br gr fb lb y r where: c = center of the shielded cable (this is a very thin blue wire) = video s = shield of the shielded cable = video bl = black = audio jack ground? br = brown = audio? gr = green = audio jack ground? fb = free blue (e.g. not to be confused with blue inside shield) = audio? lb = light brown = brightness control y = yellow = ground for 5 volt power r = red = +5 voltsI put question marks after the audio stuff because i never used or cared about it --- i used my own separate headset design. Thus the only wires you need to worry about are:
looking at the male connector, facing the prongs: c s x x x x lb y r where i use an "x" to denote "don't care", e.g. no need to use "x" wires.Important differences: when you drive this directly you need regulated 5 volts, not raw battery, and you need differential video not single-ended (the big huge "brick" shaped control box has a regulator in it and also a differential video amp) The brightness control is a voltage, typically 0 to 4 volts is the meaningful range. I use a pot to adj brightness, and i prefer this to the old user-interface with the pushbuttons.
I normally use a different connector, due to the poor reliability of these connectors. I used to use DB9, but then changed to a small 5 pin connector, connected as follows: I follow a tradition that the VV Sport end has the male and the power supply has the female (for safety reasons, e.g. accidental short otherwise more likely). I also use a new 5 conductor shielded cable since the original VVSport cable is very fragile (video portion usu. breaks first, so you could just replace that instead). The wire I use has colours different from original VVSport colours, and the rightmost column is my new colours of my new cable:
key 1 4 5 2 3 where; pin 5 is +5v pin 1 is gnd is yellow is connected to green and connected to shield at VVSport end only to avoid ground loops pin 4 is brightness (0 to 4 volts) pin 2 is shield of video cable, but now i connect to black wire of my cable pin 3 is center conductor video cable, which i connect to white, my wireThese pin numbers are easy to remember as they are closest to the approximate voltages on the wires (e.g. 5 volt wire pin 5, pin 1 is ground which is the lowest voltage and lowest pin number, etc.), and pins 2 and 3 are 2.7 volts roughly (video signal) but for positive video signal, center cond. would be higher, hence higher pin number. That way, it makes it easy to remember which wire is which. Note that the differential video signal (2.7 volts both) is for better immunity to noise (like when you walk through antitheft gates in department stores, you get less "noisecrash" effect).