Hmm. Been looking at some things on the web, and came to a couple different conclusions.
- Number of lines. I know most mention something like 30 or 30 or 40-something, in some cases up to 60 lines. Why not 525? Apparently it would take a huge disc over a yard wide. (Forgot the exact number and can't seem to find it again.) Sounds limiting, but is a disc really necessary?
- Why a disc? I know it's the easiest way to do it, but there /are/ other ways. Apparently one method was to turn the edges down on the disc to make a drum of sorts. Why not eliminate the drum entirely, and just use a sort of endless metal tape, like a wide movie reel, only steel/aluminum/stainless/whatever with pixel holes punched into it instead of plastic/equivalent with images on it. Just use the tractor-feed-like holes to propel it however fast it needs to go, and have it sorta snake around over rollers or something to take up a tiny compact space densely.
- FPS/interlacing. Not sure the best way to deal with it. If it can actually spool up to enough speed, 60 cps with interlacing wouldn't be too bad. For interlacing, just skip every other hole, then do those after the first set of holes (odds then evens or whatever.) For 30 cps I suppose you could grab both halves of the interlace and do them at the same time. Not sure what to do if forced down to 15 cps. The average between the 2 non-interlaced frames that'd be shown at 30 cps? (Yes, it's actually a hair under those numbers for NTSC-II or -III, but I'm lazy at this moment, and probably wrong on a few points anyways.)
- Color. Definitely doable. Probably use R/G/B, although I've heard of odd things like Red-Orange/Blue-Green. Simple enough. Probably use sets of high-brightness LEDs, they can change faster than lights would, wouldn't need replacing, and if colored ones were used, wouldn't need colored filters in front of them like bulbs would.
If this all sounds incredibly stupid, feel free to yell at me about it. Really, do.