Uncommon graphics mode games

A list of games that use less common graphics modes.

See also: Tricky-to-emulate games

Hi-Resolution and Interlacing
PPU Register $2133 SETINI can enable hi-resolution mode, allowing a 512-pixel horizontal resolution. This causes every even column to display the main screen, and every odd column to display the sub screen. Outside of mode 5, this is usually used as a way to do a 50% blend of the main and sub screens (a.k.a. "pseudo hi-res"). Under composite, this resulting blend can look somewhat smooth, but through S-Video or RGB the vertical stripes might be clearly visible.

In Mode 5, hi-resolution is automatically forced, and the main and subscreen are automatically overridden with alternating columns of the BG layers, allowing an effective double-width resolution.

PPU Register $2133 SETINI can enable interlacing, causing the scanlines of every second frame (field) to be offset downward by half a line. In mode 5 this allows an effective double-height resolution.

Links:
 * Forum thread - CRT photos of various hi-resolution effects.

Overscan (240 lines)
PPU Register $2133 SETINI can choose either 224 or 240 lines of visible picture. Most games used 224, allowing a significantly longer vblank period, and the extra lines weren't normally visible on contemporary NTSC televisions.

Vertical Offset-per-tile
See: Offset-per-tile

Horizontal Offset-per-tile
The horizontal version of offset-per-tile is especially rare, since scanline horizontal scroll changes can already do a smooth horizontal offset, and this hardware feature only provides a coarse one.