Super Game Boy: Enable Scanline Interlacing Mode

The Super Game Boy is a game accessory that plays original monochrome Game Boy games as well as black Game Boy Color games using the SNES console as an input interface with audio and video output display to the TV. The focal point was allowing players finally being able to play Game Boy games on a more accessible bigger screen, as well as having the ability to assign all 4 of the monochrome palettes to a 15-BIT value.

Games could also be developed to take advantage of the additional functions of the SNES, though they were almost completely wasted in games. Most developers just opted to throw up a border and palettes that were often incomplete and weren’t very good, as well as often locking out the player from changing palettes and or controller settings. Games could allow up to 4 players to play limited modes by plugging in a SNES Multitap accessory allowing Bomberman deathmatches, Street Fighter 2 tournaments and even the more obscure turn-based board games would be setup to work without passing a single controller to other players.

A small number of games offered alternate soundtracks using the SGB sound driver, games even uploaded their custom own sound samples and that was much less common. Only one game, Space Invaders actually uploaded an early version of the game running in the SGB’s RAM. The ability to write custom hooks in both RAM and ROM were also possible though never actually used in any meaningful way.

It is possible to add scanlines and screen ghosting like the original Game Boy displays using the Super Game Boy / 2 by enabling a PPU register and interlacing bit.

Actually, it may be closer to that of the Game Boy Color interlacing display; if you're using a palette that matches the original handheld it really looks close to the DMG Dot Matrix display, minus the blocks.

Included are patches for all known Super Game Boy / 2 regions and revisions because addresses are slightly offset between versions.

Known limitations
-SNES sprites are not affected by mosaic settings as a result of a hardware limitation.
-The modification is compatible with the Enable OBJ_TRN mode patch.
-Mosaics effects do not function.
-Space Invaders Arcade mode is also not affected because the Super Game Boy / program jumps to a new program and resets the hardware registers.

It is possible to add scanlines and screen ghosting like the original Game Boy displays using the Super Game Boy / 2 by enabling a PPU register and interlacing bit.

Actually, it may be closer to that of the Game Boy Color interlacing display; if you're using a palette that matches the original handheld it really looks close to the DMG Dot Matrix display, minus the blocks.

Included are patches for all known Super Game Boy / 2 regions and revisions because addresses are slightly offset between versions.

Known limitations
-SNES sprites are not affected by mosaic settings as a result of a hardware limitation.
-The modification is compatible with the Enable OBJ_TRN mode patch.
-Mosaics effects do not function.
-Space Invaders Arcade mode is also not affected because the Super Game Boy / program jumps to a new program and resets the hardware registers.


Database match: Super Game Boy (World) (Rev 2)
Database: No-Intro: Super Nintendo Entertainment System (v. 20210222-050638)
File/ROM SHA-1: 973E10840DB683CF3FAF61BD443090786B3A9F04
File/ROM CRC32: 8A4A174F