IBM 3274 51C Maintenance Information page 125

Mark new PN
using label
PN 813769
supplied
Processor Card
2
Cap Bevel
Note: The PROM patch card is used when functional changes
are required for the Integrated Modem. The PROM card connects
via a cable to the Processor Card module socket. All pluggable ROS
modules that are removed from the Processor Card are stored in a
plastic box in the
3274.
Some of these modules may be used again
when the field change updates the Processor Card with the released
level part numbers. The ROS module removal tool is shown in
Figure 5-27.
Figure 5-26. EPROM-Card-to-Processor-Card Cabling
5-28
Orange Wire
this side
EPROM Patch
Card A1 B4
00
10
20
30