
EFA CORPORATION

4M50HL2S

Processor        80486SX/80486DX/80486DX2/Pentium Overdrive
Processor Speed  20/25/33/40/50(internal)/50/66(internal)MHz
Chip Set         UMC
Max. Onboard DRAM32MB
Cache            64/128/256KB
BIOS             AMI
Dimensions       330mm x 218mm
I/O Options      32-bit VESA local bus slots (2)
NPU Options      None

[Image]

                                CONNECTIONS

  Purpose                  Location     Purpose                 Location

  External battery            J1        Reset switch              J10

  Turbo LED                   J7        32-bit VESA Local bus      S1
                                        slot

  Speaker                     J8        32-bit VESA Local bus      S2
                                        slot

  Power LED & keylock         J9

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     Factory configured - do not              J3              N/A
      alter

     Speed set Turbo                         J11              Open

      Speed normal                            J11             Closed

     CPU type package PGA                    J12           pins 2 & 3
                                                              closed

      CPU type package PQFP                   J12           pins 1 & 2
                                                              closed

     Factory configured - do not             J13           pins 2 & 3
      alter                                                   closed

     Western Digital HDD WDAC2340            J17           pins 2 & 3
      installed                                               closed

      Western Digital HDD WDAC2340 not        J17           pins 1 & 2
      installed                                               closed

     CMOS memory normal operation             W1           pins 1 & 2
                                                              closed

      CMOS memory clear                        W1           pins 2 & 3
                                                              closed

     On board battery enabled                 W2             Closed

      On board battery disabled                W2              Open

  Note:The exact location of W2 is unknown.

              DRAM CONFIGURATION

      Size          Bank 0          Bank 1

      1MB         (4) 256K x 9       NONE

      2MB         (4) 256K x 9   (4) 256K x 9

      4MB         (4) 1M x 9         NONE

      5MB         (4) 256K x 9    (4) 1M x 9

      8MB         (4) 1M x 9      (4) 1M x 9

      16MB        (4) 4M x 9         NONE

      20MB        (4) 1M x 9      (4) 4M x 9

      32MB        (4) 4M x 9      (4) 4M x 9

                  CACHE CONFIGURATION

    Size         Bank 0        Bank 1          TAG

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

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

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

                        CACHE JUMPER CONFIGURATION

   Size    W4    W5     W6     W7       W8       W9       W10       W11

   64KB    1 &   1 &    1 &   Open     Open     Open      Open     Open
            2     2     2

  128KB    2 &   1 &    2 &   1 & 2    Open     Closed    Open     Closed
            3     2     3

  256KB    2 &   2 &    1 &   2 & 3   Closed    Closed   Closed    Closed
            3     3     2

  Note:Pins designated should be in the closed position.

                          CPU TYPE CONFIGURATION

      Type        SW3/1    SW3/2     SW3/3     SW3/4     SW3/5     SW3/6

   80486SX/20      Off      Off       Off       On        On        Off

   80486SX/25      Off      Off       Off       Off       On        Off

   80486SX/33      Off      Off       Off       Off       On        Off

    80486DX        Off       On        On       Off       Off       Off

     Pentium       Off       On        On       Off       Off       Off
   Overdrive

                          CPU TYPE CONFIGURATION

     Type         J6        J13       J14       J15      JP1        JP3

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

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

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

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

  Note:Pins designated should be in the closed position.

            CPU SPEED CONFIGURATION

   Speed      SW1/1    SW1/2    SW1/3    SW1/4

   20MHz       Off      Off       On      Off

   25MHz       On       On       Off      On

   33MHz       On       Off       On      On

   40MHz       Off      Off       On      Off

  50i MHz      On       On       Off      On

   50MHz       Off      Off      Off      Off

  66i MHz      On       Off       On      On

                  VESA WAIT STATE/BUS SPEED CONFIGURATION

  CPU speed    Wait states         J4             J5             J16

     33MHz       0 wait       pins 1 & 2     pins 1 & 2      pins 1 & 2
                  states         closed         closed          closed

    > 33MHz    1 wait state    pins 2 & 3     pins 2 & 3      pins 2 & 3
                                 closed         closed          closed

