MICRONICS MOTHERBOARD

80486xx VL Bus JX30G (Baby size 09-00189-xx)

This document is for the baby-sized (13.3" x 8.5") JX30G VL-Bus motherboard.

The part number for this board is 09-00189-xx.

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

expansion slots; two 16-bit/VL-Bus expansion slots; four sockets for SIMMs; a ZIF socket

for an OverDrive CPU; IDE interface connector; one floppy connector; two serial

port connectors; one parallel port connector.

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.


PROCESSOR UPGRADE REPORT

INTEL DX4-100 5V

dyrgcmn@mcs.net has reported that he successfully upgraded his JX30G MB to

Intel DX4ODPR100 CPU with no problems. Changed the CPU clock from 25MHZ

for (DX2/50) to 33MHZ. The BIOS had been prviously upgraded with the microfirmware

version while still a DX2/50. Reports it was "plug and play".

AMD 5x86-133 with voltage regulator.

xxxxxxx has reported thet he successfully upgraded the JX30G MB to the AMD 5x86-133

with the add'l voltage regulator. No BIOS or switch settings required. "Plug and Play" install.


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 +

+ +

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

DIP switch settings for CPU selection

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

DIP Switch 1

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

CPU Speed S1 S2 S3 S4

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

33MHz or DX2/ 66MHz On On Off Off

25MHz or DX2/ 50MHz Off On Off Off

40 MHz or DX2/ 80mhz Off Off Off Off

50 Mhz On Off Off Off

The 40 and 50 MHZ settings are not documented by Micronics and appear here as a result of empirical data.

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

W12 CPU selection

Pins 2-3 486DX, 486DX2 & P24T

Pins 1-2 486SX

W13 PQFP Surface mounted 486SX

Pins 1-2 PQFP 486SX Enabled

Pins 2-3 PQFP 486SX Disabled

W4 When Local Bus Master controllers are installed {VL SCSI},

jumper W4 must be removed to support local bus DMA.

J14 Serial 16550 Port A National Semiconductor Super i/o PC87312

J9 Serial 16550 Port B National Semiconductor Super i/o PC87312

J16 Parallel Printer Port

W7 Parallel port I/O direction

Pins 2-3 Output mode (default)

Pins 1-2 Input mode (Tape Backup /Scanner)

I/O Port addresses / CMOS Setup

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

COM1 3F8h IRQ 4

COM2 2F8h 3

COM3 3E8h 4

COM4 2E8h 3

LPT1 3BCh 7

LPT2 378h 7

LPT3 278h 7

IRQ in use

--------

IRQ 6 Floppy controller

IRQ 14 Primary IDE controller

J Floppy connector

J Primary IDE connector

W21 IDE LED

Pin 1 - Signal

Pin 2 - Ground

W5 Clearing CMOS Setup

Temporarily install jumper, normal settings are open.

J8 Optional External 4.5-6.0 volt battery connector {Motorola 146818AP RTC Only}

Pin 1 - Battery Positive

Pin 2 - no connector

Pin 3 - Ground

Pin 4 - Ground

The JX30 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.

W2 Color / Monochrome Display

COLOR - Installed *

MONO - Open

W3 PS/2 Mouse @ IRQ 12

IRQ 12 enabled - Installed (NEXTStep O/S Installation)

Disabled - open

J30 External speaker

Pin 1 - Speaker

Pin 2 - no connector

Pin 3 - Ground

Pin 4 - +5 volts DC

J31 Keylock / Power LED

Pin 1 - Power LED signal

Pin 2 - no connector

Pin 3 - Ground

Pin 4 - Keyboard lock signal

Pin 5 - Ground

W20 Reset switch

Pin 1 - Signal

Pin 2 - Ground

W18 Turbo LED

Pin 1 - Signal

Pin 2 - Ground

W19 Turbo switch

Pin 1 - Signal

Pin 2 - Ground

W8 Flash ROM operation (see note below)

Pins 1-2 Recovery mode

Pins 2-3 Normal operation (default)

DO NOT change jumper W8 unless instructed by a Micronics Technical Support Engineer.

Changing the jumper will result in the Bios being Erased. You must have a Flash

recovery floppy diskette before attempting to recover. The jumper is NOT moved when

updating the Flash ROM.

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

+ +

+ Cache Configuration +

+ Direct Mapped Write Through +

+ +

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

W10 W11 W22 W23 W24

64K Cache 1-2 1-2 2-3 2-3 1-2 (9) 8k X8 Sram -20Ns for U56-U60, U67-U70, & U34 / TAG

128k 1-2 2-3 1-2 1-2 2-3 (5) 32kX8 Sram -20Ns for U56-U60, & U34

256k 2-3 2-3 2-3 2-3 2-3 (9) 32kX8 Sram -20ns for U56-U60, U67-U70, & U34

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

+ +

+ Cache Configuration +

+ Direct Mapped Write Back +

+ +

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

W16 W17

64K Cache 1-2 2-3 (1) 8k X8 Sram -20Ns for U61

128k 1-2 2-3 (1) 32kX8 Sram -20Ns for U61

256k 2-3 2-3 (1) 32kX8 Sram -20ns for U61