Tandy 1000 SL Technical Reference Manual page 574

BIOS Services
The structure and usage of the Video driver RAM data area is as fol-
lows:
HEX Offset
From Segment
oo4o:oooo
49H
4AH
4CH
4EH
50H
60H
62
65H
66H
Length and
Intended Use
1 byte
-
1 word
-
1 word
-
1
word
-
8 words-
lword
-
1 byte
-
1 byte
-
1 byte
-
current CRT mode (0-7)
screen column width
byte length of screen
address/offset of beginning of
current display page
row/col coordinates of the
cursor for each of up to 8
display pages
current cursor type (See
"Set Cursor Type" for correct
encoding)
current display page 1 word -
base address
+
4 of the CRT
controller card
copy of value written to
the Mode Select Register
current color palette setting
53.