Compaq DESKPRO 386 - Locations for the Processor, Coprocessor, and System ROM on the System Board (Assy. No. 000558); System Board (Assy. No. 000558) Switch Settings

Maintenance and Service Guide 8-5
Table 8-3. System Board (assy. no. 000558) Switch Settings
Switch
Position Number
Switch
Positions Function
1 ON Reserved
2 ON
OFF
Coprocessor installed
Coprocessor not installed (default)
3 ON
OFF
80287-3 or -6 coprocessor speed 4 MHz
80286-8 coprocessor speed 8 MHz (default)
4 ON
OFF
CPU boot speed 16 MHz except when
accessing diskette drive; then 8 MHz
(default)
CPU boot speed 16 MHz always
5 OFF Reserved
6 ON
OFF
COMPAQ VDU, COMPAQ ECG, compatible EGA,
RGBI, or VGC (default)
Third-party monochrome
7 ON
OFF
80287-3, -6, or -8 coprocessor or no
coprocessor installed (default)
80387-16 coprocessor
8 ON Reserved
Table 8-4. Locations for the Processor, Coprocessor, and System ROM on the
System Board (assy. no. 000558)
Location Description
U13 EVEN System ROM
U15 ODD System ROM
U42 Coprocessor (80287-3, -6, or -8)
U60 Coprocessor (80387-16)
U76 Processor (80386-16)