This document is for the baby-sized (13.3" x 8.5") Baby Gemini 486SX-25 motherboard.  
It is also known as the "Upgradeable" board because it can accommodate the Intel
OverDrive CPU.  The part number for this board is 09-00145-xx.

It's identifying features are: an LED between expansion slots #5 and #6; eight 16-bit 
expansion slots; four sockets for SIMMs (using 72-pin SIMMs); one proprietary 80-pin 
SIMM socket which accommodates a Micronics External Cache Card.

The bus speed for this motherboard is fixed at 8MHz.


+=============================+
+                             +
+ MOTHERBOARD SWITCH SETTINGS +
+                             +
+   * = Default setting       +
+=============================+

SW1
---
1  Memory size (see below)
2  Memory size (see below)
3  Memory size (see below)
4  Memory size (see below)

5  Reserved             *Off
6  Reserved             *Off
7  Reserved             *Off
8  Reserved             *On



DIP switch settings for memory size
===================================
Memory         Banks           DIP Switch 2
-----------------------------------------------
 MB      0    1    2    3    S1   S2   S3   S4
----    ---- ---- ---- ---- ---- ---- ---- ----
 4MB     4M                  ON   ON   ON   ON
 8MB     4M   4M             OFF  ON   ON   ON
12MB     4M   4M   4M        ON   OFF  ON   ON
16MB     4M   4M   4M   4M   OFF  OFF  ON   ON
16MB    16M                  ON   ON   OFF  ON
20MB     4M  16M             ON   ON   OFF  OFF
24MB     4M   4M  16M        ON   OFF  ON   OFF
28MB     4M   4M   4M  16M   OFF  ON   ON   OFF
32MB    16M  16M             OFF  ON   OFF  ON
36MB     4M  16M  16M        ON   OFF  OFF  OFF
40MB     4M   4M  16M  16M   OFF  OFF  ON   OFF
48MB    16M  16M  16M        ON   OFF  OFF  ON
52MB     4M  16M  16M  16M   OFF  OFF  OFF  OFF
64MB    16M  16M  16M  16M   OFF  OFF  OFF  ON

In the table above, 4M indicates that one 1Mx36 SIMM is installed in the socket,
16M indicates that one 4Mx36 SIMM is installed in the socket.  The above shows all 
of the possible memory configurations.

When installing more than 16MB of memory, BIOS relocation must be disabled.  Bios 
relocation copies the video Bios (C0000-C7FFF) and the system ROM Bios (F0000-FFFFF) into
RAM.  The motherboard adds 15MB to these addresses (F00000) to be able to differentiate 
between the ROM and RAM.  Enabling the relocation feature causes the memory above 16MB 
to become non-contiguous and therefore inaccessible.

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 JUMPER SETTINGS +
+                             +
+=============================+


J5  External 6-volt battery connector
  Pin 1 - Battery Positive
  Pin 2 - no connector
  Pin 3 - Ground
  Pin 4 - Ground

J7  Keylock / Power LED
  Pin 1 - Power LED signal
  Pin 2 - no connector
  Pin 3 - Ground
  Pin 4 - Keyboard lock signal
  Pin 5 - Ground

J8  External speaker
  Pin 1 - Speaker
  Pin 2 - no connector
  Pin 3 - Ground
  Pin 4 - +5 volts DC

W1  Turbo LED
  Pin 1 - Signal
  Pin 2 - Ground

W2  Reset switch
  Pin 1 - Signal
  Pin 2 - Ground

W3  Turbo switch
  Pin 1 - Signal
  Pin 2 - Ground