This document is for the baby-sized (13.3" x 8.5") JX30GC VL-Bus motherboard.
The part number for this board is 09-00203-xx.
It's identifying features are: an LED between expansion slots #5 and #6
Seven 16-bit ISA expansion slots
Two 32-bit VL-Bus/ISA expansion slots
Four sockets for 72 pin x 36 bit SIMMs
A ZIF socket for an OverDrive CPU
Two 40 pin EIDE interface connectors.
One 34 pin floppy connector
Two 16650 based 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 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 i486DX/4 100 Mhz allows the system board and VL Bus to run at 33MHZ
The i486DX/4 75 Mhz allows the system board and VL Bus to run at 25MHZ
The ISA bus speed for this motherboard is set at 8.33MHz. The CPU clock speed is determined by the clock synthesizer. If the CPU is a 486SX-25, 486DX2-50, or 486DX4/75 the Bus
clock speed is 1/3. For the 486SX-33, 486DX-33, 486DX2-66 and i486DX4/100 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
DIP switch 1 settings for CPU selection
CPU CLK Speed S1 S2 S3 S4 33MHz :DX/33, DX2/66, DX4/100MHz On On Off Off 25MHz :DX/25, DX2/50, DX4/75 MHz Off On Off Off
W12 CPU selection
Pins 2-3 486DX, 486DX2, 486DX/4 & 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 SMC Super I/O FDC37c665
J9 Serial 16550 Port B SMC Super I/O FDC37c665
J16 Parallel Printer Port
W36 Parallel Printer port IRQ selection
1-2: IRQ 7
2-3: IRQ 5
W37, W38 Reserved / No jumpers installed
I/O Port addresses / CMOS Setup
------------------
COM1 3F8h IRQ 4 COM2 2F8h IRQ 3 COM3 3E8h IRQ 4 COM4 2E8h IRQ 3 LPT1 378h IRQ 7 /5 LPT2 278h IRQ 7 /5
IRQ in use {Autodisable if other controllers needs to use IRQs}
--------
IRQ 6 Floppy controller
IRQ 14 Primary IDE controller
IRQ 15 Secondary IDE controller
J27 Floppy connector
J26 Primary IDE connector
J32 Secondary 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 JX30GC 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
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.
WRITE THROUGH CACHE JUMPER CONFIGURATION
W10 W11 W22 W23 W24 64K 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 / TAG 256k 2-3 2-3 2-3 2-3 2-3 (9) 32kX8 Sram -20ns for U56-U60, U67-U70, & U34 / TAG
+=============================+
WRITE BACK CACHE JUMPER CONFIGURATION CONFIGURATION
W16 W17 64K 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