IBM 6151 Maintenance And Service Manual page 53

Source Number
The left two digits of the SRN is the source number. The left digit
of the source number identifies the device for the first SRA
number. The FRUs for the other SRA numbers may be located in
other devices. The right digit of the source number identifies the
procedure that produced the SRN. The following table identifies
the devices and procedures. Use the following SRN for an
example.
13-234-100-B34-D64
Device
Procedure
1 . System uni
t
1 - Resident POST program
2 - Display
2 . Loadable POST program
3 - Keyboard
3 - Standalone diagnostic program
4 - Tape drive 4 - Licensed program product
5 - Printer
5 - Support center
6 - Plotter
6 - Problem determination procedures
7 - Expansion unit
7 - The device was not found when the
8 - Mouse
diagnostic programs loaded
9 - Attached 8 - Reserved
communications 9 - Reserved
device
0- Reserved
0- Reserved
A - Tablet
B - Dials Feature
C - LPFK Feature
E - Portable disk drive
(6/88) Diagnostics 2-21