Measurement Computing Digital488 - Manual (Page 37)

Section 3 Command Descriptions
3.7
OUTPUT 718;"D123ZX" send 12 bits of data to the least significant bits
ENTER 718; A$ read data from the Digital488
DISP A$ display shows 0000000123
OUTPUT 718;"P5D21ZX" set port 5 only
OUTPUT 718;"P0X" select all ports
ENTER 718; A$ read data from the Digital488
DISP A$ display shows 2100000123