
J-MARK COMPUTER CORPORATION

JET-486DX/SX 20/25 NON-CACHE

Processor         80486SX/80486DX
Processor Speed   20/25/33MHz
Chip Set          ETEQ
Max. Onboard DRAM 32MB
Cache             None
BIOS              AMI
Dimensions        220mm x 220mm
I/O Options       None
NPU Options       80487SX

[Image]

                                CONNECTIONS

  Purpose                   Location   Purpose                   Location

  Reset switch                J1       Turbo switch                J4

  Power LED & keylock         J2       External battery            JP1

  Speaker                     J3       Turbo LED                   JP5

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     Monitor type select color                JP2            Closed

      Monitor type select monochrome           JP2             Open

     CMOS memory normal operation             JP3            Closed

      CMOS memory clear                        JP3             Open

     Factory configured - do not alter       JP12            Closed

     Oscillator speed select 25MHz           JP13           pins 1 & 2
                                                              closed

      Oscillator speed select 20MHz           JP13           pins 2 & 3
                                                              closed

              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) 1 M x 9

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

      16MB        (4) 4M x 9         NONE

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

                          CPU TYPE CONFIGURATION

     Type           JP8            JP9           JP10           JP11

    80486SX         Open          Open        pins 1 & 2      pins 1 & 2
                                                closed         closed

    80487SX        Closed         Open           Open         pins 2 & 3
                                                               closed

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

                        CHIPSET TYPE CONFIGURATION

     Type           JP6            JP7           JP14            JP15

    82C493       pins 1 & 2     pins 2 & 3     pins 2 & 3     pins 1 & 2
                  closed         closed         closed          closed

    82C492       pins 2 & 3     pins 1 & 2     pins 1 & 2     pins 2 & 3
                  closed         closed         closed          closed

