IBM Aptiva Handbook page 82

The system board, sometimes called the planar or
motherboard, is the main circuit board in the tower. It
supports a variety of devices and provides other basic
computer functions that are preinstalled or that you can
install later. The system board shown on page 65 has
the following parts:
1
Power switch connector (J22). Holds the connector
from the power switch.
2
Power supply connector (J23). Holds the three-wire
connector from the power supply.
3
12V speaker connector (J14). Holds the connector
for 12V speakers.
4
Power supply connector (J11). Holds connectors P1
and P2 from the power supply.
5
Local Bus IDE connector 1 (J5). Holds signal cables
that attach to drives 1 and 2.
6
Local Bus IDE connector 2 (J6). Holds signal cables
that attach to drives 3 and 4.
7
Diskette connector (J17). Holds signal cables that
attach to diskette and tape drives.
8
Power supply connector (J12). Holds connector P11
from the power supply; connector P10 attaches to the
riser card.
9 Regulator socket (J3). Holds the processor regulator
or programming block, if installed.
10
Processor socket (U2). Holds the processor (CPU).
11
Processor. A Pentium class central processing unit.
12 Heat sink. Prevents the processor from overheating.
66 Chapter 6: Working with system board components
Cache memory module socket (J4). Can hold a
13
256 KB or 512 KB cache memory module. Any cache
memory module you install must meet the following
specifications.
Specifications: 160-pin; 64-bit; 256 KB (32 KB x 64) or
512 KB (64 KB x 64); 9 nanosecond (ns); synchronous
pipeline burst SRAM.
14
System memory module sockets for DIMMs (J9,
J10). Hold dual inline memory modules (DIMMs). Any
system memory module you install must meet the
following specifications to prevent damage to the
system board.
Specifications: 168-pin; 64-bit; 8 MB, 16 MB, or
32 MB; gold contacts; unbuffered; 3.3V; synchronous
dynamic random access memory (SDRAM) or
60 nanosecond (ns) extended data out (EDO).
Other types of memory may appear to fit
Attention! the DIMM sockets on the system board, but
when forced, can damage the sockets.
15
Battery (BT1). A 3-volt (CR2032) lithium battery. If you
replace the battery, you must use the same type.
VESA feature connector (J19). Used for motion
16
video adapter cards, such as a television card.
If you are installing a feature connector cable that came
with your computer, the cable will cover all the pins on
this connector. If you are installing a feature connector
cable that did not come with your system, the cable
may not use all of the pins on this connector. If it does
not use all the pins, you should align the cable with
pin 1 on the system board (closest to the monitor
connector).