Laser display (was Re: Orlando hamfest)

From: Philip Pemberton <>
Date: Wed Feb 16 04:42:09 2005

In message <200502151743.MAA22766_at_Sparkle.Rodents.Montreal.QC.CA>
          der Mouse <> wrote:

> >> the foundation for a Laser MAME rig (who wants to play "Star Wars"
> >> on the living room wall? Anyone?
> > Now THAT would be cool, but I'd rather play Asteroids. Wonderful
> > monochrome vectors - much cheaper :)
> :-)

ISTR there was another game I wanted to play on one of my machines - there
was a star in the middle of the screen, and two ships. The ships tended to
move towards the star, and the objective was for one player to destroy the
other player's ship by firing missiles. Not sure why, but the name "Spacewar"
springs to mind.
That would be fun to play on a scanned laser display - Spacewar projected
onto the side of someone's house :)

> However, remember that you can do lissajous figures easily with speaker
> "motors", since both deflection signals are sine waves. A game like
> Tempest or Asteroids or etc requires _very_ high acceleration rates out
> of the deflectors, or you get things like rounded corners, and very
> good linearity, or you get non-straight lines.

Ick. More fun.

> You also need to be
> able to do at least several thousand, probably several tens of
> thousands, of lines per second to get reasonably flicker-free displays.

There was an article in Circuit Cellar magazine that covered a scanned-laser
display. I think it used galvanometers to do the scanning (instead of

> It might be enough to use mirrors on piezo actuators, but I
> wouldn't count on it without testing it.

[fx]: philpem goes looking for mirror tiles, piezo discs, neodymium hard
drive magnets and magnet wire.

Phil.                              | Acorn Risc PC600 Mk3, SA202, 64MB, 6GB,              | ViewFinder, 10BaseT Ethernet, 2-slice,          | 48xCD, ARCINv6c IDE, SCSI
... Eventually land east of San Andres fault will fall into the Atlantic.
Received on Wed Feb 16 2005 - 04:42:09 GMT

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