
UNITRON COMPUTER, INC.

486SX SYSTEM

Processor              80486SX/80486DX
Processor Speed        25/33MHz
Chip Set               UMC
Max. Onboard DRAM      32MB
SRAM Cache             32/128KB
BIOS                   Phoenix
Dimensions             346mm x 218mm
I/O Options            Floppy drive interface, game port, IDE interface,
                       modem interface, parallel port, serial port (2),
                       VGA port
NPU Options            4167 (location unverified)

[Image]

                                CONNECTIONS

  Purpose                  Location   Purpose                    Location

  Game port                  C1       IDE interface                J22

  VGA port                   C2       Modem interface              J23

  Parallel port              C3       Turbo LED                    J26

  Serial port 2              C4       Power LED                    J28

  Serial port 1              C5       Floppy drive interface       J31

  Fan power                  J3

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     Serial port 1 (CN5) enabled             J18           pins 1 & 2
                                                              closed

      Serial port 1 (CN5) disabled            J18           pins 2 & 3
                                                              closed

     Serial port 1 (CN5) select COM1         J19           pins 1 & 2
      (I/O address 3F8-3FFh)                                  closed

      Serial port 1 (CN5) select COM3         J19           pins 2 & 3
      (I/O address 3E8-3EFh)                                  closed

     Parallel port (C3) select LPT1          J20           pins 1 & 2
      interrupt IRQ7 at 378-37F                               closed

      Parallel port (C3) select LPT2          J20           pins 2 & 3
      interrupt IRQ5 at 278-27F                               closed

     Parallel port (CN3) enabled             J21           pins 1 & 2
                                                              closed

      Parallel port (CN3) disabled            J21           pins 2 & 3
                                                              closed

     IDE interface (J22) enabled             J25           pins 1 & 2
                                                              closed

      IDE interface (J22) disabled            J25           pins 2 & 3
                                                              closed

     Floppy drive interface (J31)            J27           pins 1 & 2
      enabled                                                 closed

      Floppy drive interface (J31)            J27           pins 2 & 3
      disabled                                                closed

     Serial port 2 (CN4) select COM2         J29           pins 1 & 2
      (I/O address 2F8-2FFh)                                  closed

      Serial port 2 (CN4) select COM4         J29           pins 2 & 3
      (I/O address 2E8-2EFh)                                  closed

     Serial port 2 (CN4) enabled             J30           pins 1 & 2
                                                              closed

      Serial port 2 (CN4) disabled            J30           pins 2 & 3
                                                              closed

                DRAM CONFIGURATION

      Size            Bank 0           Bank 1

       1MB        (1) 256K x 36         NONE

       2MB        (1) 256K x 36    (1) 256K x 36

       3MB        (1) 512K x 36    (1) 256K x 36

       4MB         (1) 1M x 36          NONE

       5MB        (1) 256K x 36     (1) 1M x 36

       8MB         (1) 1M x 36      (1) 1M x 36

      12MB         (1) 2M x 36      (1) 1M x 36

      16MB         (1) 2M x 36      (1) 2M x 36

      32MB         (1) 4M x 36      (1) 4M x 36

                          CPU TYPE CONFIGURATION

           CPU                     JP1                      JP2

         80486DX            pins 1 & 2 closed       pins 1 & 2 and 3 & 4
                                                           closed

         80486SX                   open              pins 2 & 3 closed

  Note:The location of jumpers JP1 and JP2 is unknown.

                         SRAM JUMPER CONFIGURATION

    Size           J7          J10         J11         J13         J14

    32KB          open       pins 1 &    pins 1 &    pins 1 &    pins 1 &
                                2           2           2           2

    128KB        closed      pins 2 &    pins 2 &    pins 2 &    pins 2 &
                                3           3           3           3

  Note:Pins designated should be in the closed postion.

                    SRAM CONFIGURATION

     Size        Cache SRAM      Location         TAG

     32KB        (4) 8K x 8       CACHE       (1) 8K x 8

     128KB      (4) 32K x 8       CACHE       (1) 32K x 8

  Note:This configuartion is unverified.

                         VRAM CONFIGURATION

         Size                   VRAM                 Location

         256KB               (2) 44256                Bank 0

         512KB               (4) 44256             Banks 0 & 1

          1MB                (8) 44256         Banks 0, 1, 2 and 3

