Analyzer Messages
Interpreting Analyzer Messages
The Video RAM Failure Code.
The last four digits identify the failure address for the video RAM on
the A16 assembly. A video RAM failure code indicates an internal
failure on the A16 assembly; the section of the video RAM circuitry that
is tested is not connected to other instrument assemblies. Convert the
four digits to binary and interpret them with
Table 14-6
A16 Video Ram Address Failure Code Interpretation
Digits From
Example
* The acronym MAD stands for "Multiplexed Address and Data." There are
no separate address and data lines within the A16 video RAM.
636
Equivalent
Binary Value
F →
8
→
4
→
2
→
1
8
7 →
4
→
2
→
1
8
4
2 →
2
1
D →
8
→
4
2
→
1
Table
14-6.
A16 Circuit Tested
Error at MAD 15 *
Error at MAD 14
Error at MAD 13
Error at MAD 12
Error at MAD 11
Error at MAD 10
Error at MAD 9
Error at MAD 8
Error at MAD 7
Error at MAD 6
Error at MAD 5
Error at MAD 4
Error at MAD 3
Error at MAD 2
Error at MAD 1
Error at MAD 0
A16 Reference
Designator
U306
U305
U306
U305
U306
U305
U306
U305
U306
U305
U306
U305
U306
U305
U306
U305
Chapter 14