GRAPHICS CONTROLLER BOARD
With the 32Kbytes of graphics memory, the system can create a
640 x 400 resolution image. Upper and lower case characters are
displayed in a 6 x 9 dot pattern on a 8 x 16 dot matrix which
allows for descended lower case characters. The graphic controller
operates in mixed mode. It can draw the following figures: hori
zontal and vertical lines, vectors, rectangles, arcs, circles, graphic
character symbols, line pattern or area pattern, and slanted figures
(+n x 45). Also, the CRT controller supports scrolling, zooming
set mask, reset mask, replace complement and clear screen. Re
verse and normal video, blink attribute and half intensity are also
available. (See NEC 7220 data sheets)
The graphics controller board is connected directly onto the
controller board with two connectors, J/P 113, and J/P 114. The
pin assignments for these connectors are shown in Figure 2.12.
Pin assignments P114
Pin assignments P113
Figure 2.12 Graphic controller connections
The graphics controller board for color systems has a memory
capacity of 96Kbytes, and can display eight colors — black, white,
red, green, blue, yellow, magenta, and cyan.
In the text mode the characteristics are:
• 25 lines, 80 characters per line
• Characters in any of the eight colors
• Background in any of the eight colors
• Blinking attribute
2-18
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