
INTEL CORPORATION

R486SX254F/R486SX33F/R486DX334F/R486DX2664F

Processor     80486SX/80487SX/80486DX/ODP486SX/80486DX2/Pentium Overdrive
Processor     25/33/50(internal)/66(internal)MHz
Speed
Chip Set      VLSI
Max. Onboard  32MB
DRAM
Cache         64/128/256KB
BIOS          Phoenix
Dimensions    330mm x 218mm
I/O Options   32-bit proprietary riser card slot, floppy drive
              interface,IDE interface, parallel port, PS/2 mouse
              port,serial ports (2), VGA feature connector, VGA port
NPU Options   None

[Image]

                                CONNECTIONS

  Purpose                  Location     Purpose                Location

  VGA port                    J1        Floppy drive             J15
                                        interface

  Parallel port               J2        +5V auxiliary fan        J26
                                        power

  Serial port 2               J3        IDE interface LED        J29

  Serial port 1               J4        Power LED &              J30
                                        Keylock

  PS/2 mouse port             J5        Reset switch             J31

  32 Bit proprietary          J7        +12V auxiliary fan       J32
  riser card                            power

  VGA feature                J10        External speaker         J33
  connector

  IDE interface              J14

  Note:To connect an external speaker, remove the jumper from pins 3 & 4
  and connect external speaker between pins 1 & 4.

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     FLASH BIOS programming enabled           J12           pins 1 & 2
                                                              closed

      FLASH BIOS programming disabled          J12           pins 2 & 3
                                                              closed

     Normal FLASH operation                   J13           pins 1 & 2
                                                              closed

      Invoke boot block recovery               J13           pins 2 & 3
                                                              closed

     Enable onboard video                     J16           pins 1 & 2
                                                              closed

      Disable onboard video                    J16           pins 2 & 3
                                                              closed

     Disable floppy drive write               J17           pins 2 & 3
      protect                                                 closed

      Enable floppy drive write protect        J17           pins 1 & 2
                                                              closed

     Enable password                          J20           pins 2 & 3
                                                              closed

      Disable password                         J20           pins 1 & 2
                                                              closed

     Enable user to enter Setup               J21           pins 1 & 2
                                                              closed

      Prevent user to enter Setup              J21           pins 2 & 3
                                                              closed

     CMOS normal operation                    J28            Closed

      CMOS clear upon power-up                 J28             Open

                DRAM CONFIGURATION

      Size            Bank 0           Bank 1

       2MB        (1) 512K x 36         NONE

       4MB        (1) 512K x 36    (1) 512K x 36

       4MB         (1) 1M x 36          NONE

       6MB        (1) 512K x 36     (1) 1M x 36

       6MB         (1) 1M x 36     (1) 512K x 36

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

       8MB         (1) 2M x 36          NONE

      10MB         (1) 2M x 36     (1) 512K x 36

      10MB        (1) 512K x 36     (1) 2M x 36

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

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

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

      16MB         (1) 4M x 36          NONE

      18MB        (1) 512K x 36     (1) 4M x 36

      18MB         (1) 4M x 36     (1) 512K x 36

      20MB         (1) 1M x 36      (1) 4M x 36

      20MB         (1) 4M x 36      (1) 1M x 36

      24MB         (1) 2M x 36      (1) 4M x 36

      24MB         (1) 4M x 36      (1) 2M x 36

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

                    CACHE CONFIGURATION

     Size          Bank 0         Bank 1          TAG

     64KB        (4) 8K x 8     (4) 8K x 8    (1) 32K x 8

     128KB      (4) 32K x 8        NONE       (1) 32K x 8

     256KB      (4) 32K x 8    (4) 32K x 8    (1) 32K x 8

                      CACHE JUMPER CONFIGURATION

               Size                               J11

               64KB                               Open

               128KB                    pins 1 & 2, 5 & 6 closed

               256KB                pins 1 & 2, 3 & 4, 7 & 8 closed

                          CPU TYPE CONFIGURATION

    CPU Type         J22            J23           J24            J25

    80486SX       pins 1 & 2     pins 2 & 3    pins 2 & 3     pins 2 & 3
                    closed        closed         closed         closed

    80487SX       pins 2 & 3     pins 1 & 2    pins 2 & 3     pins 1 & 2
                    closed        closed         closed         closed

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

    80486DX2      pins 2 & 3     pins 1 & 2    pins 1 & 2     pins 2 & 3
                    closed        closed         closed         closed

    ODP486SX      pins 2 & 3     pins 1 & 2    pins 2 & 3     pins 1 & 2
                    closed        closed         closed         closed

                   CPU SPEED CONFIGURATION

      CPU Speed              J18                  J19

        25MHz          pins 1 & 2 closed   pins 1 & 2 closed

        33MHz          pins 1 & 2 closed   pins 2 & 3 closed

       50iMHz          pins 1 & 2 closed   pins 1 & 2 closed

       66iMHz          pins 1 & 2 closed   pins 2 & 3 closed

             VRAM CONFIGURATION

     Size          Bank 0        Bank 1

     512K        (4) 256 x 4      NONE

      1MB        (4) 256 x 4   (4) 256 x 4

