
ABC COMPUTER COMPANY, LTD.

A4865

Processor         80486DX
Processor Speed   33MHz
Chip Set          OPTI
Max. Onboard DRAM 32MB
Cache             64/128/256/512KB
BIOS              AMI
Dimensions        330mm x 218mm
I/O Options       32-bit external memory card slot
NPU Options       4167

[Image]

                                CONNECTIONS

  Purpose                   Location    Purpose                  Location

  External battery            J10       Turbo LED                 JP12

  Power LED & Keylock         J23       Reset switch               SW1

  Speaker                     J24       Turbo switch               SW2

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     Monitor type select color                JP1            Closed

      Monitor type select monochrome           JP1             Open

     CMOS memory normal operation             JP2           pins 2 & 3
                                                              closed

      CMOS memory clear                        JP2           pins 1 & 2
                                                              closed

     Normal operation - do not alter         JP205            Open

      Factory test (system burn in)           JP205           Closed

                            DRAM CONFIGURATION

     Size          Bank 0        Bank 1         Bank 2         Bank 3

     4MB         (4) 1M x 9       NONE           NONE           NONE

     8MB         (4) 1M x 9    (4) 1M x 9        NONE           NONE

     12MB        (4) 1M x 9    (4) 1M x 9     (4) 1M x 9        NONE

     16MB        (4) 1M x 9    (4) 1M x 9     (4) 1M x 9     (4) 1MB x 9

     16MB        (4) 4M x 9       NONE           NONE           NONE

     20MB        (4) 1M x 9    (4) 4M x 9        NONE           NONE

     24MB        (4) 1M x 9    (4) 1M x 9     (4) 4M x 9        NONE

     28MB        (4) 1M x 9    (4) 1M x 9     (4) 4M x 9     (4) 1M x 9

     32MB        (4) 4M x 9    (4) 4M x 9        NONE           NONE

     36MB        (4) 1M x 9    (4) 4M x 9     (4) 4M x 9        NONE

     40MB        (4) 1M x 9    (4) 1M x 9     (4) 4M x 9     (4) 4M x 9

     48MB        (4) 4M x 9    (4) 4M x 9     (4) 4M x 9        NONE

     52MB        (4) 1M x 9    (4) 4M x 9     (4) 4M x 9     (4) 4M x 9

     64MB        (4) 4M x 9    (4) 4M x 9     (4) 4M x 9     (4) 4M x 9

  Note:Banks 2 & 3 are utilized when a 32-bit external memory card is
  installed.

                           CACHE CONFIGURATION

     Size          Bank 0         Bank 1          Tag         Dirty Bit

     64KB        (8) 8K x 8        NONE       (1) 8K x 8     (1) 64K x 1

     128KB       (8) 8K x 8     (8) 8K x 8    (1) 8K x 8     (1) 64K x 1

     256KB      (8) 32K x 8        NONE       (1) 32K x 8    (1) 64K x 1

     512KB      (8) 32K x 8    (8) 32K x 8    (1) 32K x 8    (1) 64K x 1

                        CACHE JUMPER CONFIGURATION

   Size         JP8         JP9         JP10        JP11         JP206

   64KB        open         open        open        open       pins 2 & 3
                                                                closed

   128KB      closed        open        open       closed      pins 2 & 3
                                                                closed

   256KB      closed       closed       open       closed      pins 2 & 3
                                                                closed

   512KB      closed       closed      closed      closed      pins 1 & 2
                                                                closed

