Usable modes for !Scroller



Modes     Resolution  Colours     k/screen   required memory

Normal modes:                               

Mode 12 : 640  x 256   16 cols     80k        160k
Mode 15 : 640  x 256  256 cols     160k       320k

Overscan modes

Mode 50 : 768  x 288   16 cols     107k       192k
Mode 51 : 832  x 288  256 cols     234k       416k

Hi-res modes

Mode 52 : 1152 x 288   16 cols     162k       288k
Mode 53 : 1024 x 288   256 cols    288k       448k

Mode 54 : 1024 x 256   16 cols     128k       224k
Mode 55 : 1024 x 256   256 cols    256k       416k
  
Mode 56 : 1024 x 288   16 cols
(This is included for compatibility with Mode 53)      

Rules for modes :

Required memory must be greater than 1.5 x k/screen

Required memory must be a multiple of 32k to have a mode compatible 
with all Acorn machines. It must be a multiple of the page size of 
the machine on which it is run.

Memory per screen line = X / 2 for 16 col modes
                       = X for 256 col modes

Required memory - k/screen must be a multiple of memory per screen line

Eg. Mode 12
mps = 320 bytes (640/2)
(128-80)*1024 / 320 = 153, hence mode 12 is an acceptable mode

                                                 
Here is a list of all possible modes gives the above rules

16 Colour Modes :

Multi-Sync and VGA modes

X=1024     Y=576    SM=294912       TM=458752
X=960      Y=576    SM=276480       TM=491520
X=896      Y=576    SM=258048       TM=458752
X=832      Y=576    SM=239616       TM=425984
X=768      Y=576    SM=221184       TM=393216
X=704      Y=576    SM=202752       TM=360448
X=640      Y=576    SM=184320       TM=327680
X=1024     Y=544    SM=278528       TM=425984
X=960      Y=544    SM=261120       TM=491520
X=896      Y=544    SM=243712       TM=458752
X=832      Y=544    SM=226304       TM=425984
X=768      Y=544    SM=208896       TM=393216
X=704      Y=544    SM=191488       TM=360448
X=640      Y=544    SM=174080       TM=327680
X=1024     Y=512    SM=262144       TM=425984
X=960      Y=512    SM=245760       TM=491520
X=896      Y=512    SM=229376       TM=458752
X=832      Y=512    SM=212992       TM=425984
X=768      Y=512    SM=196608       TM=393216
X=704      Y=512    SM=180224       TM=360448
X=640      Y=512    SM=163840       TM=327680
X=1024     Y=480    SM=245760       TM=393216
X=960      Y=480    SM=230400       TM=491520
X=896      Y=480    SM=215040       TM=458752
X=832      Y=480    SM=199680       TM=425984
X=768      Y=480    SM=184320       TM=294912
X=704      Y=480    SM=168960       TM=360448
X=640      Y=480    SM=153600       TM=327680

Standard Resolution Modes

X=1152     Y=288    SM=165888       TM=294912
X=1024     Y=288    SM=147456       TM=229376
X=960      Y=288    SM=138240       TM=491520
X=896      Y=288    SM=129024       TM=229376
X=832      Y=288    SM=119808       TM=425984
X=768      Y=288    SM=110592       TM=196608
X=704      Y=288    SM=101376       TM=360448
X=640      Y=288    SM=92160        TM=163840
X=1152     Y=256    SM=147456       TM=294912
X=1024     Y=256    SM=131072       TM=229376
X=960      Y=256    SM=122880       TM=491520
X=896      Y=256    SM=114688       TM=229376
X=832      Y=256    SM=106496       TM=425984
X=768      Y=256    SM=98304        TM=196608
X=704      Y=256    SM=90112        TM=360448
X=640      Y=256    SM=81920        TM=163840
X=1152     Y=250    SM=144000       TM=294912
X=1024     Y=250    SM=128000       TM=196608
X=960      Y=250    SM=120000       TM=491520
X=896      Y=250    SM=112000       TM=229376
X=832      Y=250    SM=104000       TM=425984
X=768      Y=250    SM=96000        TM=196608
X=704      Y=250    SM=88000        TM=360448
X=640      Y=250    SM=80000        TM=163840

256 Colour modes

Multi-Sync / VGA Modes

X=640      Y=480    SM=307200       TM=491520
X=640      Y=448    SM=286720       TM=491520
X=768      Y=416    SM=319488       TM=491520
X=640      Y=416    SM=266240       TM=491520
X=768      Y=384    SM=294912       TM=491520
X=640      Y=384    SM=245760       TM=491520
X=1024     Y=288    SM=294912       TM=458752
X=960      Y=288    SM=276480       TM=491520
X=896      Y=288    SM=258048       TM=458752
X=832      Y=288    SM=239616       TM=425984
X=768      Y=288    SM=221184       TM=393216
X=704      Y=288    SM=202752       TM=360448
X=640      Y=288    SM=184320       TM=327680


Standard Resolution Modes

X=1024     Y=288    SM=294912       TM=458752
X=960      Y=288    SM=276480       TM=491520
X=896      Y=288    SM=258048       TM=458752
X=832      Y=288    SM=239616       TM=425984
X=768      Y=288    SM=221184       TM=393216
X=704      Y=288    SM=202752       TM=360448
X=640      Y=288    SM=184320       TM=327680

X=1024     Y=256    SM=262144       TM=425984
X=960      Y=256    SM=245760       TM=491520
X=896      Y=256    SM=229376       TM=458752
X=832      Y=256    SM=212992       TM=425984
X=768      Y=256    SM=196608       TM=393216
X=704      Y=256    SM=180224       TM=360448
X=640      Y=256    SM=163840       TM=327680

X=1024     Y=250    SM=256000       TM=393216
X=960      Y=250    SM=240000       TM=491520
X=896      Y=250    SM=224000       TM=458752
X=832      Y=250    SM=208000       TM=425984
X=768      Y=250    SM=192000       TM=294912
X=704      Y=250    SM=176000       TM=360448
X=640      Y=250    SM=160000       TM=327680
