MICRONICS MOTHERBOARD

80486xx VESA LB cache (09-000165-xx)

This document is for the baby-sized (13.3" x 8.5") MX30 VL-Bus motherboard.

The part number for this board is 09-00165-xx.

It's identifying features are: an LED between expansion slots #5 and #6; seven 16-bit

expansion slots; two 32-bit VL-Bus /ISA expansion slots; four sockets for SIMMs; a ZIF socket

for an OverDrive CPU.

The VESA Local Bus speed is determined by the CPU speed. If the CPU is a 486SX-25, or 486DX2-50, the VL-Bus bus speed is 25MHz. If the CPU is a 486SX-33, 486DX-33, or 486DX2-66, the VL-Bus

bus speed is 33MHz. A 50 MHZ CLK is not yet a current VESA standard specification

The ISA bus speed for this motherboard is set at 8.33MHz. The CPU clock speed is

determined by the Oscillator. If the CPU is a 486SX-25, or 486DX2-50, the Bus

clock speed is 1/3. For the 486SX-33, 486DX-33, or 486DX2-66 CPUs, the Bus

clock speed is 1/4.

The following shows all of the possible memory configurations.

MEMORY CHART CONFIGURATION

===================================

Memory Banks

----------------------------

MB 0 1 2 3

---- ---- ---- ---- ----

1MB 1M

2MB 1M 1M

4MB 4M

6MB 1M 1M 4M

8MB 4M 4M

10MB 1M 1M 4M 4M

12MB 4M 4M 4M

16MB 4M 4M 4M 4M

16MB 16M

18MB 1M 1M 16M

20MB 4M 16M

24MB 4M 4M 16M

32MB 16M 16M

36MB 4M 16M 16M

40MB 4M 4M 16M 16M

48MB 16M 16M 16M

64MB 16M 16M 16M 16M

In the table above, 1M indicates that one 256x36 SIMM is installed in the socket,

4M indicates that one 1Mx36 SIMM is installed in the socket, 16M indicates that,

one 4Mx36 SIMM is installed in the socket.

Micronics Computers has tested and verified the following 1Mx36 memory brands:

Micron Technologies, Mitsubishi, Samsung, Texas Instruments, Toshiba

Micronics Computers has tested and verified the following 4Mx36 memory brands:

Mitsubishi, Samsung, Toshiba

+======================================+

+ +

+ MOTHERBOARD SWITCH & JUMPER SETTINGS +

+ +

+======================================+

Jumper settings for CPU selection

=====================================

----------------------

CPU Speed W20 W21

-------------------------------------------

33MHz or DX2/ 66MHz 1-2 2-3

25MHz or DX2/ 50MHz 2-3 2-3

CPU selection

PQFP Surface mounted 486SX OVERDRIVE ZIF SOCKET W22 W23 W24

i486SX NONE 1-2 1-2 1-2

i486SX i486DX/DX2 2-3 2-3 2-3

i486SX OVERDRIVE 2-3 2-3 1-2

NONE i486SX 1-2 1-2 1-2

NONE (UNIVERSAL) i486DX/DX2 2-3 2-3 2-3

W3 When Local Bus Master controllers are installed {VL SCSI},

jumper W3 must be removed to support local bus DMA.

W14 Local Bus Wait State

0-Wait state : 1-2 * default

1-wait state : 2-3

W4 Clearing CMOS Setup

Temporarily install jumper, normal settings are open.

The MX30 Motherboard does not require an external battery to be installed.

The Dallas / Benchmarq Real Time Clock Chip contains an internal battery for an approximate lifetime of 8-10 years.

W6 Color / Monochrome Display

COLOR - OPEN *

MONO - INSTALLED

J24 External speaker

Pin 1 - Speaker

Pin 2 - no connector

Pin 3 - Ground

Pin 4 - +5 volts DC

J28 Keylock / Power LED

Pin 1 - Power LED signal

Pin 2 - no connector

Pin 3 - Ground

Pin 4 - Keyboard lock signal

Pin 5 - Ground

W25 Reset switch

Pin 1 - Signal

Pin 2 - Ground

W27 Turbo LED

Pin 1 - Signal

Pin 2 - Ground

W26 Turbo switch

Pin 1 - Signal

Pin 2 - Ground

+=============================+

+ +

+ Cache Configuration +

+ Direct Mapped Write Through +

+ +

+=============================+

W8 W11 W13 W18 W19

64K Cache 2-3 2-3 1-2 1-2 1-2 (9) 8k X8 Sram -20Ns for U36-U39, U43-U46 & U41

128k 1-2 1-2 2-3 2-3 1-2 (5) 32kX8 Sram -20Ns for U36-U39, & U41

256k 2-3 2-3 2-3 2-3 2-3 (9) 32kX8 Sram -20ns for U36-U39, U43-U46 & U41