This document is for the baby-sized (8.5" x 13.3") 386SX-20 and 386SX-25 non-cached motherboard. The part number for this board is 09-00105-xx. It's identifying features are: an LED between expansion slots #5 and #6; six 16-bit expansion slots, and two 8-bit expansion slots; eight sockets for SIMMs (four banks of 2); a socket for a 80387SX coprocessor. The bus speed for this motherboard is fixed at 8MHz. +=============================+ + + + MOTHERBOARD JUMPER SETTINGS + + + +=============================+ J1 External keyboard connector Pin 1 - Keyboard clock Pin 2 - Keyboard data Pin 3 - no connector Pin 4 - Ground Pin 5 - +5 volts DC J13 Monitor type Not connected Color video card Connected Monochrome video card J14 Coprocessor configuration Pins 1-2 Coprocessor installed Not connected Coprocessor not installed J15 80386 Pipeline configuration Connected 80386 pipeline access Not connected 80386 non-pipeline access J24 External 6-volt battery connector Pin 1 - Battery Positive Pin 2 - no connector Pin 3 - Ground Pin 4 - Ground J28 Turbo switch Pin 1 - Signal Pin 2 - Ground J29 Turbo LED Pin 1 - Signal Pin 2 - Ground J30 Reset switch Pin 1 - Signal Pin 2 - Ground J31 External speaker Pin 1 - Speaker Pin 2 - no connector Pin 3 - Ground Pin 4 - +5 volts DC J32 Keylock / Power LED Pin 1 - Power LED signal Pin 2 - no connector Pin 3 - Ground Pin 4 - Keyboard lock signal Pin 5 - Ground +========================+ + + + MEMORY CONFIGURATION + + + +========================+ Listed below are the possible memory configurations Size in Bank Bank Bank Bank MB 0 1 2 3 ----------------------------------- 0.5 256K 1.0 256K 256K 1.5 256K 256K 256K 2.0 256K 256K 256K 256K 2.0 1MB 2.5 256K 1MB 3.0 256K 256K 1MB 4.0 1MB 1MB 4.5 256K 1MB 5.0 256K 1MB 6.0 1MB 1MB 1MB 8.0 1MB 1MB 1MB 1MB 8.0 4MB 8.5 256K 4MB 9.0 256K 256K 4MB 10.0 1MB 4MB 12.0 1MB 1MB 4MB 16.0 4MB 4MB 256K = Two 256Kx9 SIMMs in the bank 1MB = Two 1Mx9 SIMMs in the bank 4MB = Two 4Mx9 SIMMs in the bank