Modelist for ArcemModes
An adapted form of Arcemmodes (as distributed with !Arcem) is loaded by default
in the so-called 5th-column ROM space. This enables a number of extra modes
above number 46.
Modes up to ~46 are defined and listed in the Riscos User Guide. Higher modes
were used by demos and games but numbering does not seem to be consistent.
If a demo/game does not work, try to disable ArcemModes (*rmkill arcemmodes,
inside the emulation of course!) and see if that helps, for instance for the
!Jojo demo.
In the following list a few additional modes have been defined for low-bpp, low
framerate, high X and Y. Remember the Archimedes videochip only had 10 bits
for its screen geometry (max. 2048X1024) and the DMA chip only allowed
2^15 *16 bytes, ie. 512 Kb; for video purposes there is even less as sound
also has to find some space there. Displayable screen cannot go up to 2048 X 1024
as there also have to be sync pulses. And, VIDC did 'only' 36 Mpixels/second
so framerate will be very slow, no problem for emulation but don't use this
Arcemmodes module in slow, high-definition modes on a real Archimedes computer.
And, before applying a mode, Riscos 3 'vets' them so may refuse them (modes 97
and 98).

Mode 32 800 X 600, 256 col, 45 Hz
Mode 66 632 X 266, 16 col, 50 Hz
Mode 67 632 X 266, 256 col, 50 Hz
Mode 82 869 X 352, 16 col, 57 Hz
Mode 83 869 X 352, 256 col, 57 Hz
Mode 96 1920 X 1016, 4 col, 12 Hz
Mode 97 1920 X 536, 16 col, 12 Hz, refused
Mode 98 960 X 536, 256 col, 12 Hz, refused
Mode 99 1280 X 720, 16 col, 25 Hz 
Mode 100 1024 X 768, 2 col, 29 Hz
Mode 101 1024 X 768, 4 col, 29 Hz
Mode 102 1024 X 768, 16 col, 29 Hz
Mode 104 1280 X 1016, 2 col, 17 Hz
Mode 105 1280 X 1016, 4 col, 17 Hz
Mode 108 1152 X 864, 2 col, 23 Hz
Mode 109 1152 X 864, 4 col, 23 Hz
Mode 112 1400 X 520, 16 col, 30 Hz
Mode 120 1600 X 600, 16 col, 24 Hz
Mode 122 240 X 320, 2 col, 80 Hz (does not display correctly)
Mode 123 240 X 320, 4 col, 80 Hz
Mode 124 240 X 320, 16 col, 80 Hz
Mode 125 240 X 320, 256 col, 80 Hz
 