0.6 For Advanced Users; 0.6.1 Video Memory Organization - Commodore PC 20 User Manual

Table D.2.
in Vi eo on 19urations
1\v d Cft
ATl Graphics Co-exists with
Solution as
Monochrome ATl as CGA
Adapter IBMCGA
Monochrome ATlas CGA
Graphics Color/Emulat. Adapt.
Hercules Color
Color/Graphics or ATl asMGA
Emulation or IBMMDA
Plantronics Hercules Graphics
IBM EGA
640 x 200
nothing
16 colors
ATl -ATI Graphics Solution Adapter
CGA - Color/Graphics Adapter
MDA - Monochrome Display Adapter
MGA - Monochrome Graphics Adapter
EGA - Enhanced Graphics Adapter
0.6 For Advanced Users
Conflicts with
IBMMDA
Hercules Gr.
IBMMDA
Hercules Gr.
IBMCGA
Color/Emulat.
Adapter
Hercules Col.
everything
The ATl Graphics Solution is designed to incorporate a number of
video display features into one board. Care should be taken when
programming the ATl Graphics Solution to avoid video memory
contlict or selection of the wrong display mode. Damage to the
monitor may result due to wrong programming parameters. You
should read through this chapter before attempting to program the
ATl Graphics Solution.
0.6.1 Video Memory Organization
The ATl Graphics Solution has 64K bytes of video memory. The
video memory is organized into two banks with 32K bytes in each
bank. The physical address of the video memory will depend on the
user-selected display mode.
1. ATI GRAPHICS SOLUTION CONFIGURED IN THE COLOR!
GRAPHICS MODE OR EMULATION MODE.
There are 16K bytes of video memory available for the
alphanumeric mode and the graphiCS mode. There are four
submodes of operation.
Using AT!
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