Specifications

E271-2201 Controller 113
from the Base I/O Port address as selected by jumpers J0 and J1 (see Selecting the
Base I/O Port, page 18). The functions and formats of these registers are defined
below:
Base Port
8-Bit Mode Contains the X coordinate
12-Bit Mode Contains the high-order byte of the X or Y coordinate
Base Port+1
8-Bit Mode Contains the Y coordinate
12-Bit Mode Contains the low-order byte of the X or Y coordinate
Base Port+2
Contains controller status as defined below:
Bit Hex
0 01 1 = 8-Bit Mode 0 = 12-Bit Mode
1 02 always 0
2 04 1 = Stream Mode 0 = Single-Point Mode
3 08 always 0
4 10 always 0
5 20 always 0
6 40 1 = X data 0 = Y data
7 80 1 = data ready 0 = not ready
Base Port+3
Not supported.
Coordinate Data Format
The coordinate data is formatted as follows:
8-Bit Mode
two-byte transfer
Base Port XXXX XXXX X coordinate data
Base Port+1 YYYY YYYY Y coordinate data
12-Bit Mode
first two-byte transfer
Base Port XXXX XXXX X high order byte
Base Port+1 XXXX 0000 X low order byte
second two-byte transfer
Base Port YYYY YYYY Y high order byte
Base Port+1 YYYY 0000 Y low order byte