
SEE-THRU DATA SYSTEMS, LTD.

STO98C

Processor            80386DX/CX486DLC/80486SX/80487SX/80486DX/80486DX2
Processor Speed      20/25/33/40/50(internal)/50/66(internal)
Chip Set             OPTI
Max. Onboard DRAM    32MB
SRAM Cache           64/128/256KB
BIOS                 MR
Dimensions           220mm x 220mm
I/O Options          None
NPU Options          None

[Image]

                                CONNECTIONS

  Purpose                   Location    Purpose                  Location

  External battery             J9       Turbo switch              JP12

  Power LED & keylock         J18       Turbo LED                 JP13

  Speaker                     JP11      Reset switch               S1

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     Monitor type select monochrome           JP1             open

      Monitor type select color                JP1            closed

     CMOS memory normal operation             JP2           pins 2 & 3
                                                              closed

      CMOS memory clear                        JP2           pins 1 & 2
                                                              closed

                            SRAM CONFIGURATION

   Size      Cache      Location      TAG (U31)   TAG (U32)    Dirty Bit
                                                                 (U42)

   64KB     (8) 8K x   Banks 0 & 1      NONE       (1) 8K x   (1) 16K x 4
               8                                      8

   128KB     (4) 32K     Bank 0         NONE       (1) 8K x   (1) 16K x 4
              x 8                                     8

   128KB     (4) 32K     Bank 0         NONE      (1) 32K x   (1) 16K x 4
              x 8                                     8

   256KB     (8) 32K   Banks 0 & 1      NONE      (1) 32K x   (1) 16K x 4
              x 8                                     8

   256KB     (8) 32K   Banks 0 & 1    (1) 8K x     (1) 8K x   (1) 16K x 4
              x 8                        8            8

                         SRAM JUMPER CONFIGURATION

     Size           JP3            JP4            JP7            JP8

     64KB        pins 2 & 3     pins 2 & 3        open           open
                  closed          closed

    128KB        pins 1 & 2     pins 1 & 2       closed          open
                  closed          closed

    128KB        pins 1 & 2     pins 1 & 2       closed          open
                  closed          closed

    256KB        pins 2 & 3     pins 2 & 3       closed          open
                  closed          closed

   256KB 1       pins 2 & 3     pins 2 & 3        open          closed
                  closed          closed

  Note 1 :Jumpers are in this position only when using (2) 8K x 8 in TAG
  sockets U31 & U32.

              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

  Note:8 or 9-bit SIMMs can be used.

                          CPU SPEED CONFIGURATION

         Speed              JF0         JF1         JP6          JP10

         20MHz            closed      closed     pins 2 & 3      open
                                                   closed

         25MHz             open       closed     pins 2 & 3      open
                                                   closed

   33MHz(386/486DLC)      closed       open      pins 2 & 3    pins 1 & 2
                                                   closed       closed

       33MHz(486)         closed       open      pins 2 & 3      open
                                                   closed

         40MHz             open        open      pins 2 & 3    pins 1 & 2
                                                   closed       closed

    50MHz (internal)       open       closed     pins 2 & 3      open
                                                   closed

         50MHz             open       closed     pins 1 & 2    pins 2 & 3
                                                   closed       closed

    66MHz (internal)      closed       open      pins 2 & 3      open
                                                   closed

                          CPU TYPE CONFIGURATION

     Type       JP5       JP9      JP14      JP15     JP16        JP17

   80386DX     1 & 2,    1 & 2,   1 & 2     1 & 2     2 & 3,     closed
               3 & 4     3 & 4                        4 & 5

   CX486DLC    1 & 2,    1 & 2,   1 & 2     1 & 2     2 & 3,     closed
               3 & 4     3 & 4                        4 & 5

   80486SX     2 & 3     open     1 & 2     2 & 3     2 & 3,      open
                                                      4 & 5

   80487SX     1 & 2,    2 & 3    2 & 3     2 & 3     2 & 3,      open
               3 & 4                                  4 & 5

   80486DX     1 & 2,    1 & 2    2 & 3     2 & 3     2 & 3,      open
               3 & 4                                  4 & 5

   80486DX2    1 & 2,    1 & 2    2 & 3     2 & 3     2 & 3,      open
               3 & 4                                  4 & 5

  Note:The location of JP15 is unknown. Pins designated should be in the
  closed position

