Kaypro 10 - Video Graphics and Attributes Command Set

Video Graphics and Attributes Command Set
The KAYPRO 10 has a graphics and attributes set that currently includes draw-
ing and erasing
lines, drawing and erasing pixels, inverse video, reduced intensity,
blinking fields, graphics characters, cursor positioning, and cursor on/off.
Drawing Graphics
To draw graphics on the KAYPRO 10, the screen is treated as an array 100 pixels
high, and 160 pixels wide. Any spot on the screen can be addressed by a vertical
coordinate (ranging from 32 to 131) and a horizontal coordinate (ranging from 32
to 191). The pixel in the upper left corner of the screen has coordinates of 32,32.
It would seem natural to start the numbering of coordinates at 1 or O. However,
some byte values of 32 or less are interpreted by BDOS as control keys.
Line and
pixel graphics are drawn on the screen by writing an escape sequence
to the console output. For the purpose of drawing lines and pixels, an escape se-
quence is a 4- or 6-byte sequence defined as follows :
Escape sequence =
ESC <sequen ce-type> <V1> <H1> [<V2> <H2>]
where:
1 }
ESC is an ascii 27 (1 B hex).
2} <sequence-type> is a character of the set:
1<
(space)
L
D
to write a pixel
to erase a pixel
to draw a line
to delete a line
3} V1, H1, V2, H2 are 1-byte values indicating locations on the screen.
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