Screen size memory requirements

  +----------+-------------+-------------+-------------+-------------+-------------+
  |          |                               Columns                               |
  |          +-------------+-------------+-------------+-------------+-------------+
  |          |    160      |    320      |    640      |    960      |   1280      |
  |Rows Colrs|     20      |     40      |     80      |    120      |    160      |
  +----------+-------------+-------------+-------------+-------------+-------------+
  |        2 |   5K  &1400 |  10K  &2800 |  20K  &5000 |  30K  &7800 |  40K  &A000 |
  | 256    4 |  10K  &2800 |  20K  &5000 |  40K  &A000 |  60K  &F000 |  80K &14000 |
  |  32   16 |  20K  &5000 |  40K  &A000 |  80K &14000 | 120K &1E000 | 160K &28000 |
  |      256 |  40K  &A000 |  80K &14000 | 160K &28000 | 240K &3C000 | 320K &50000 |
  +----------+-------------+-------------+-------------+-------------+-------------+
  |        2 |  10K  &2800 |  20K  &5000 |  40K  &A000 |  60K  &F000 |  80K &14000 |
  | 512    4 |  20K  &5000 |  40K  &A000 |  80K &14000 | 120K &1E000 | 160K &28000 |
  |  64   16 |  40K  &A000 |  80K &14000 | 160K &28000 | 240K &3C000 | 320K &50000 |
  |      256 |  80K &14000 | 160K &28000 | 320K &50000 | 480K &78000 | 640K &A0000 |
  +----------+-------------+-------------+-------------+-------------+-------------+
  |        2 |  15K  &3C00 |  30K  &7800 |  60K  &F000 |  90K &16800 | 120K &1E000 |
  | 768    4 |  30K  &7800 |  60K  &F000 | 120K &1E000 | 180K &2D000 | 240K &3C000 |
  |  96   16 |  60K  &F000 | 120K &1E000 | 240K &3C000 | 360K &5A000 | 480K &78000 |
  |      256 | 120K &1E000 | 240K &3C000 | 480K &78000 | 720K &B4000 | 960K &F0000 |
  +----------+-------------+-------------+-------------+-------------+-------------+
  |        2 |  20K  &5000 |  40K  &A000 |  80K &14000 | 120K &1E000 | 160K &28000 |
  |1024    4 |  40K  &A000 |  80K &14000 | 160K &28000 | 240K &3C000 | 320K &50000 |
  | 128   16 |  80K &14000 | 160K &28000 | 320K &50000 | 480K &78000 | 640K &A0000 |
  |      256 | 160K &28000 | 320K &50000 | 640K &A0000 | 960K &F0000 |1280K &140000|
  +----------+-------------+-------------+-------------+-------------+-------------+