IBM Aptiva 2142 - Manual (Page 155)

Processor Bus Factor—Type A-2
The Processor speed jumpers are set to the manufacture Type and Model of
the Aptiva computer. Changing jumper settings are not supported and might
cause system failures.
Figure 5-4. Pentium II Processor Speed—Type A-2
Pentium II Jumper 233
MHz
266
MHz
Processor Speed MHz JP7 1-2, 5-6 1-2, 3-4
7-8
Parts/Test Point Locations 5-7