Tandy 1000 SL Technical Reference Manual page 539

Software
Set Palette Registers
Sets palette registers.
Entry Conditions
AH
=
10H
AL
=
0: Set Palette register
BL
BH
=
color value to store
=
number of palette register (0 -15) to set
AL
=
1 : Set border color register
BH
=
color value to store
AL
=
2: Set palette color value to store and
border registers
ES:DX points to a 17-byte list.
Bytes 0-15
=
values forpalette registers
0-15
Byte 16
=
value for border register
18.