#### Back to index | # Info for genesis

#### Sega Megadrive/Genesis

Usage:
Under the "Options" menu, accessible by hitting TAB, you will find the following option:
"Country" - this allows you to alter the 'flavour' of Genesis, to either European, Japanese
or American. Many cartridges compare their country codes with that of the Genesis itself and
may behave differently, or lock up if the two types do not match.
'Auto' attempts to auto-set the Genesis country code to the value the cartridge will appear
to be checking for. This may not be 100% accurate, however.

Known Issues:
Most games tend to run fairly well. Some have slight graphic glitches, incorrect colours part
way down the screen or other bizarre effects. See genesis.crc for a partial list.
Cartridges up to 32MBit (4MByte) are supported.
The controller may not work well with some games. This will be resolved when more information
is obtained. Similarly, 6-button joypads aren't emulated yet.
Split screen effects and interlacing are not yet supported.
Sprite/layer priority should be perfect.
Sound is emulated at Z80 and PSG76489 level.
I still consider the Genesis driver extremely preliminary. I have a lot of further work to do
before I consider it anywhere near complete. My initial goal is to make it as compatible as
possible. Currently there is scope within the driver to handle split screen colour changes/any
VDP effect, interlacing, without rewriting. The graphics renderer emulates VDP at scanline
level, and does not use tile-based methods.
Wanted: Any Sega Megadrive information! Information is extremely sparse; typically the same
three-four documents, with parts incomplete, conflicting, and corrupted. Specifically, some
of the finer points of DMA transfer, and access of the 68K memory map by the Z80. Generally,
points which conflict with themselves in the documentation available on the net...

created on Tue Jan 01 12:56:01 2002