
This is the score display module. It is a custom laser cut acrylic frame with 512 hand-soldered LED's. (Anyone who didn't already think I wasn't beyond hardcore can now think again.) They are wired with a common cathode (negative) leads and an 8-bit bus going horizontal.
Thus, you put an 8-bit value into the memory and select the column with 6 bits (thus 64 columns) Four 4:16 multiplexers and some logic IC's (not seen, behind the frame) then decode the 6 bits and allow that column to sink ground. All other columns stay high (like Towlie) and thus don't light.
To make a display you have to raster the bits very quickly. Right now all I have to use is my old Basic Stamp 2, which is fast enough for a small display but not for this. But I can test this and it works great.
For the final machine (in 2010 or whenever) I plan to use a dedicated processor for the display. At first I thought about using a Propeller for everything and having 1 cog do the raster but that would eat up 14 I/O pins since it requires its own bus.
I also have an EEPROM which I can map to the display to show graphics, animation and what not.