Commodore PC 10 - 0.6.3 Mode Select Registers

42 Operations Guide
Plantronics 640 x 200 4 Colors
In this mode, 1 bit from each plane is combined to form a pixel C
with 4 color combinations.
b7 b6 b5
b4
b3 b2 b1 bO
Plane 0
cO cO cO cO cO cO cO
cO
Plane 1 c1 c1 c1 c1 c1 c1
c1
c1
1 st 2nd 3rd 4th
5th 6th 7th 8th
pel pel pel pel pel pel
pel pel
ATI 640 x 200 16 Colors
The video data format in this mode is the same as the 320 x 200
16 colors mode.
0.6.3 Mode Select Registers
I/O registers for:
PC monochrome adapter mode
Hercules graphics mode
Monochrome 132-column text mode
Emulation mode
The following lists the va registers used in these modes:
3bO - 3bl: synonym for 3b4 - 3b5
3b2 - 3b3: synonym for
3b4 - 3b5
3b4: 6845 CRT controller register address port
3b5: 6845 CRT controller register data port
3b8: (write only)
bit 0: unused
bit 1: 0 = text mode (default)
1 = Hercules graphics mode
bit 2: unused
bit 3: 0 = disable video
1
= enable video
bit 4:
unused
bit 5: 0 = disable blink
1
= enable blink
bit 6:
unused
bit 7: 0 = Graphics page 0 displayed
1
= Graphics page 1 displayed