Talk:Master Gear
resolution conversion
[edit]Got a bit of a debate going on with someone else, the outcome of which may be useful info to put on this page:
How does the MGC fit the Master System's 256x192 screen into the GG's 160x144? Simply cut the edges off? Print the sprites and background tiles closer together? Digitally shrink the image data (by a factor of... 1.33? 1.6? Or just 2.0) ? ... or did the GG have the full 256x192 mode available (or even full-rez NTSC at ???x480 / x525, onto which the GG and SMS modes were mapped with different numbers of virtual lines vs actual logical ones), that was shrunk to fit by analogue circuitry?
I wouldn't be surprised if the display system was actually the guts of an LCD TV without the tuner (given that you could plug one in as an add-on), to which the display hardware passed a composite baseband signal rather than TTL RGB. You could roughly scale a 192-height display from the SMS to fit in 384 TV lines, which would be the same as 128 lines for the GG if it's mode used a 3x multiplier (144x4 = 432). Plus, with the same pixel aspect ratio, 256 width x 2 becomes 171 x 3 (in other words, 160x3 = 240x2)... or less, if a little bit of horizontal squashing is acceptable.
Adjust the overscan to suit, and both will fit nicely enough, with the SMS image having a little bit of letterboxing, and a little bit of pan-scan cut-off. The GG screen always did seem like it had additional anti-aliasing for some reason, like it wasn't actually a digital 160x144 image mapping direct to a 160x144 matrix, but instead a screen mode designed to fit fairly neatly with the available hardware, then piped to it over an analogue method. Depending on the de-interlacing method used (144x3 would mean each game line would have 2 "real" lines in one field, 1 in the other, alternating on a line by line basis), every other on-screen line could well be partly the sum of two neighbouring ones, which is roughly the observed effect. Still about the same resolution, but with a bit of vertical "motion blur" permanently applied. Wasn't an issue, there was never a need for pixel-perfect jumps and it just made things seem less pixelated and with a better range of colours...
(Old pocket tvs often had quite ludicrous amounts of overscan anyway, so it wouldn't be much of a stretch to zoom it enough to almost or completely remove the display border) 193.63.174.211 (talk) 14:16, 18 May 2012 (UTC)