Modes Of Operation - IBM RT Series Hardware Reference Manual

processor, and character generator. Two clock sources (14 MHz
and 16 MHz) provide the dot rate. The clock is multiplexed
under processor I/O control. Four I/O registers also resident on
the card are not part of the LSI devices.
Modes of Operation
IBM Color Display
The following table describes the modes supported by BIOS on
the IBM Color Display:
ALPHA
BUFFER BOX MAX.
MODE
#
TYPE COLORS FORMAT START SIZE PAGES RESOLUTION
0 A/N 16 40x25 88000 8x8 8 320x200
1 A/N 16 40x25 88000 8x8 8 320x200
2 A/N 16 80x25 88000 8x8 8 640x200
3
A/N 16 80x25 88000 8x8 8 640x200
4
APA 4 40x25 88000
8x8 1
320x200
5 APA 4 40x25 88000 8x8
1
320x200
6
APA 2 80x25 88000 8x8 1 640x200
D
APA 16
40x25
A8000 8x8 2/4/8 320x200
E
APA 16
80x25 A8000
8x8 1/2/4 640x200
Modes 0 through 6 emulate the support provided by the IBM
Color/Graphics monitor Adapter.
Modes 0,2 and 5 are identical to modes 1,3 and 4 respectively at
the adapter's direct drive interface.
The Maximum Pages fields for modes D and E indicate the
number of pages supported when 64K, 128K or 256K bytes of
graphics memory is installed, respectively.
IBM Enhanced Graphics Adapter 5