Jumper And Switch Settings; System Board Overview - Compaq PORTABLE 386 Maintenance And Service Manual

Chapter 9. Jumper and Switch Settings
Chapter 9.1 Introduction
This chapter provides jumper and switch settings for the COMPAQ
PORTABLE 386 Personal Computer.
remember that the default settings shown are set for the system as configured
by Compaq Computer Corporation.
the system configuration is changed.
If the jumpers are changed in a COMPAQ PORTABLE 386 Personal Computer, the
SETUP program must be run to change the system configuration information
stored in CMOS memory.
Self Test errors.
The COMPAQ PORTABLE 386 Personal Computer has a configuration label, located
on the inside of the rear panel, that shows the computers jumper settings.
Chapter 9.2 System Board
The COMPAQ PORTABLE 386 Personal Computer system board is a multifunctional
board that provides configuration capability selections including:
o Parallel Interface Options
o Memory Size
o System Operating Speed
o Plasma Display Mode
o Serial Interface Options
The system board jumper settings are factory set for compatibility with most
system applications.
follows:
o E1, E2, and E7 set the parallel interface options.
o E3, E4, E8, and E9 set asynchronous communications (serial) interface
options.
o E5 and E6 enable or disable the fixed disk drive and indicate whether the
primary or secondary I/O address is used.
o E13, E14, E15, E16, and E17 indicate the total amount of 32 bit RAM
installed and determine how much RAM is to be used as base memory.
o E19 enables or disables the fail safe timer.
o E20 indicates whether or not an 80387 coprocessor is installed.
o E21 selects either the AUTO or HIGH speed mode at power on.
o E23 selects the plasma display mode at power on.
When using the tables in this chapter,
These settings need to be changed only when
Failure to run this procedure may result in Power On
The functional capability of each jumper operates as