1. Introduction

This manual has been written to be useful for two purposes. Firstly, to help you be more familiar with the system board. Secondly, to serve as a guide to both procedures and a specifications for future system upgrading.

1.1. General specification on PX486 P3 main board

• Two-third of the baby AT size board (220mm x 250 mm)
• Support 486DX/25/33/50Mhz, 486DX2/50/66Mhz and Intel P24T CPU.
• Use OPTi-SLC (82C495SLC & 82C206) Chipset.
• Support up to 32MB of main memory.
• Support 256K, 1MB and 4MB SIMM RAMs in memory configurations.
• Support shadow RAM for system, adaptor and video BIOS.
• Three VESA Local bus standard slots (one bus slave, two bus master). (*one or two bus master slots --- optional).
• Three 16-bit AT bus slots and one 8-bit XT bus slots.
• Rechargeable battery and external battery connector on board.
• Standard reset, keylock, speaker, turbo LED connectors.

1.2. VESA local bus

There are three local bus slots (one or two bus master slots, two or one bus slave slots). The local bus slot has adopted the VESA local bus solution, and the pin assignments has been connected in Micro Channel Architecture connector form.

With PAL (U47) :

J18 and J19 are bus master slots, J21 is bus slave slot.

Without PAL (U47) :

J19 is bus master slot, J18 and J21 are bus slave slots.

2. Jumper Settings and Connectors Pin Assignment

The settings of various jumpers are shown as follows:

2.1. CMOS power source (JP1)

"*" Default setting, same as below.

2.2. CPU & Frequency selection

* See quick setup A(i) & A(ii)

2.3. Mono/Color display selection (JP2)

Jumper JP2 informs the system what type of display is currently in use.

2.4. VESA local bus selection

* See quick setup (D)