Using MAME on an Arcade Monitor  
MAME and Monitors
Arcade Monitors
Saturn Mod
Arcade Primer
Finding a Cabinet
IC Pinouts
The 3 'Mode Types'
The preceding list of available resolutions contains modes of the following 'Types'
   Unchained VGA
   Unchained 'half y' VGA

These have the following meanings

Unchained VGA
For historic reasons, normal VGA modes are confined in size to 64K
This places a severe limit on the resolutions that are available to you, however it's possible to split up
or 'unchain' the VGA video memory so that it has access to 4 64K 'planes'

This means you can now access 256K of memory, allowing far more resolutions
It's not quite that simple - as there's still only 64K of memory 'mapped' to PC memory at any one time
which means blitting in these modes is slighty more complex than it is in normal VGA modes.

The advantage of having 4 times the memory generally out weighs the extra programming overhead though
  All MAME's unchained VGA modes are 8bit
i.e. they are all 256 colour modes

Unchained 'half y' VGA
These are identical to the unchained VGA modes except they can be used to 'fake' medium-res
on a standard/lowres arcade monitor
The 2 modes (512x448 and 512x512) could not be displayed on an arcade monitor without interlacing,
the 'y' resolution is simply too high.

To get round this, the 2 modes only display every other horizontal display line
- but keep the correct aspect ratio
The produces a very stable picture and ,on medium-res raster games, the effect is fairly convincing.

Again, these 2 modes are 8bit modes(256 colours)

The 640x480 SVGA mode is just that -
a normal SVGA mode reprogrammed to run on an arcade monitor

It's slighty complicated by the fact that there is no SVGA register set standard,
so drivers would have to be written for each SVGA chipset in order for it to work on all cards

At the moment, there are 2 SVGA drivers in MAME -

For a detailed discussion about the SVGA arcade monitor mode see the next few pages
Using MAME's SVGA Arcade Monitor Mode

The SVGA mode supports both 8bit and 16bit colour depth

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