Checking a display code – Quantum Data 801GC User Manual
Page 119
5-7
Some computers and video controller cards look for
the display codes and automatically adjust their hard-
ware to output an appropriate video signal format
for the display that is connected.
Problems can occur if a display outputs the wrong
code and it is connected to a computer having an
automatic format adjustment feature. The wrong sig-
nal may be generated and the display may appear
to be broken.
The 801G* is capable of checking the status of the
code pins in its D-sub connectors. These pins are
identified as M0 through M3 in table 5-1. Each sig-
nal format in the 801G* can be independently set-
up to test one or more of the display code pins. The
formats also can be set-up with the expected code.
The “Format” test image shows both the expected
code and the code that is read as a single hexidecimal
numbers. The following table shows the equivalent
hex code values for all possible input combinations.
A “0” indicates a grounded or logic low input and
“1” indicates either a floating or logic high input
❖
The 801G* merely reads and displays the code.
It does not automatically select or modify signal
format data based on the code.
Some of the built-in industry standard formats have
been set-up to check for the proper codes. The fol-
lowing tables list the formats and the expected iden-
tification codes. The tables also show which pins
need to be open (1) or grounded (0) to create the
correct code.
Table 5-2
Display Code Values
for all Sense Line
Combinations
Checking a
Display Code
Code M3
M2
M1
M0
Code M3
M2
M1
M0
0
0
0
0
0
8
1
0
0
0
1
0
0
0
1
9
1
0
0
1
2
0
0
1
0
A
1
0
1
0
3
0
0
1
1
B
1
0
1
1
4
0
1
0
0
C
1
1
0
0
5
0
1
0
1
D
1
1
0
1
6
0
1
1
0
E
1
1
1
0
7
0
1
1
1
F
1
1
1
1
D i s p l a y C o n n e c t i o n & D i s p l a y C o d e s