Tandy 1000 SL Technical Reference Manual page 533

Software
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Scroll active page up.
Entry Conditions
AH
=
6
AL =
numbers of lines to scroll. The number of lines that
Will be left blank at the bottom of the window.
(0
=
blank entire window)
CH
=
row of upper left comer of scroll window
CL
=
column of upper left comer of scroll window
DH
=
row of lower right corner of scroll window
DL
=
column of lower tight corner of scroll window
BH
=
attribute (alpha modes) or color (graphics modes)
to be used on blank line
Attributes
Color modes.
Foreground color:
Bit 0
=
blue
Bit1
=
green
Bit2
=
red
Bit 3
=
intensity
All bits off
=
black
Background color:
Bit
4 =
blue
Bit5
=
green
Bit6
=
red
Bit 7
=
blink
All bits off
=
white