This document is for the baby-sized (13.3" x 8.5") 80486DX-33, DX2/66, DX-50, and
80486SX-25 EISA motherboard. The part number for this board is 09-00159-xx.
It's identifying features are: an LED between expansion slots #5 and #6; eight 32-bit
expansion slots; four sockets for SIMMs (four banks); a ZIF socket for
any DX, DX2, SX & Intel P24T Overdrive. The First 6 EISA slots support Bus Mastering Controllers.
The Standard EISA bus clock is fixed at 8.3MHz.
+=============================+
+ +
+ MEMORY CHART +
+ +
+ +
+=============================+
The following chart shows all of the possible memory configurations
============================
Memory Banks
----------------------------
MB 0 1 2 3
---- ---- ---- ---- ----
4MB 1MB
8MB 1MB 1MB
12MB 1MB 1MB 1MB
16MB 1MB 1MB 1MB 1MB
16MB 4MB
20MB 1MB 4MB
24MB 1MB 1MB 4MB
32MB 4MB 4MB
36MB 1MB 4MB 4MB
40MB 1MB 1MB 4MB 4MB
48MB 4MB 4MB 4MB
52MB 1MB 4MB 4MB 4MB
64MB 4MB 4MB 4MB 4MB
In the table above 70ns or 60ns access time for DRAM /SIMMs is required,
1MB indicates that a 1Mx36 SIMM is installed in the bank, and 4MB indicates that
a 4Mx36 SIMMs are installed in the bank.
(1Mx36) = 4MB / 4096Kb of RAM and (4Mx36) = 16MB / 15360Kb of RAM
Micronics Computers has tested and verified the following memory brands:
Toshiba, Siemens, Mitsubishi, NEC & Micron
+=============================+
+ +
+ MOTHERBOARD JUMPER SETTINGS +
+ +
+=============================+
J23 Keyboard connector
Pin 1 - Keyboard clock
Pin 2 - Keyboard data
Pin 3 - no connector
Pin 4 - Ground
Pin 5 - +5 volts DC
J3 External 6-volt battery connector
Pin 1 - Battery Positive
Pin 2 - no connector
Pin 3 - Ground
Pin 4 - Ground
J13 External speaker
Pin 1 - Speaker
Pin 2 - no connector
Pin 3 - Ground
Pin 4 - +5 volts DC
J11 Keylock / Power LED
Pin 1 - Power LED signal
Pin 2 - no connector
Pin 3 - Ground
Pin 4 - Keyboard lock signal
Pin 5 - Ground
J9 Reset switch
Pin 1 - Signal
Pin 2 - Ground
J8 Turbo switch
Pin 1 - Signal
Pin 2 - Ground
J5 Turbo LED
Pin 1 - Signal
Pin 2 - Ground
J12 Video mode
Color - INSTALLED {Default}
MONO - OPEN
CPU SELECTION
i486SX ZIF Socket
PQFP Surface mounted CPU Selection JP1 JP2 JP3
None i486SX 1-2 3-4 2-3
None i486DX or I486DX2 2-3 1-2 1-2 & 3-4
i486SX NONE 1-2 3-4 2-3
i486SX i486DX OR DX/2 2-3 1-2 1-2 & 3-4
i486SX i487SX 1-2 1-2 1-2 & 3-4
i486SX i486SX Overdrive 1-2 2-3 1-2 & 3-4
For Earlier Revisions Ax J6
i486SX 2-3
i486DX 1-2 & 3-4
CPU Clock Speed J7 J10
33Mhz OFF ON i486DX/33, DX2/66, SX/33
25Mhz ON ON i486SX/25, DX2/50
50Mhz OFF OFF i486DX/50
Cache configuration
===================
Cache J15 J16 J17 J18 J19 J20 J21 J22
----------------------------
64K 1-2 1-2 1-2 1-2 1-2 1-2 2-3 3-4
(8) 8Kx8 -20ns SRAM for U110-U116 & U118
(1) 64Kx1 -20ns SRAM for U103
(1) 32Kx8 -20NS SRAM for U104
128K 2-3 1-2 1-2 2-3 1-2 1-2 1-2 4-5
(4) 32Kx8 -20ns SRAM for U110-U112 & U118
(1) 64Kx1 -20ns SRAM for U103
(1) 32Kx8 -20NS SRAM for U104
256K 2-3 2-3 1-2 1-2 1-2 1-2 1-2 1-2
(8) 32Kx8 -20ns SRAM for U110-U116 & U118
(1) 64Kx1 -20ns SRAM for U103
(1) 16Kx4 -20NS SRAM for U101 & U102
512K 2-3 2-3 2-3 2-3 2-3 2-3 1-2 4-5
(4) 128Kx8 -20ns SRAM for U105-U108
(1) 64Kx1 -20ns SRAM for U103
(1) 32Kx8 -20ns SRAM for U104
U101 & U102 SRAM must be removed from a 256k cache configuration.