IBM 5150 Hardware Maintenance Manual

April 2011
IMPORTANT
1. The motherboard described in this document is the
first motherboard, the 16KB-64KB one.
Examples:
* Pages 200-3 and 200-4: Do not apply to the later
64KB-256KB motherboard (different bank size).
* Page 4-7: Part number shown for the system board
(motherboard) is for the 16KB-64KB one.
2. If the BIOS on the 16KB-64KB motherboard has
been upgraded to the third revision one, then the
switch settings shown for SW2 ("switch 2", on pages
5-6 and 5-8) on the motherboard no longer apply.
The BIOS revision can be determined by examination of
the seven digit number on motherboard chip U33.
First revision: 5700051
Second revision: 5700671
Third revision: 1501476