NCR CORPORATION

PC916/PC920

Processor         80386DX
Speed             16/20MHz
Chip Set          Unidentified
Max. Onboard DRAM None
BIOS              Unidentified
Cache             None
Dimensions        290mm x 106mm
I/O Options       Proprietary external memory bus
NPU Options       80287/80387

[Image]

                                CONNECTIONS

      Purpose          Location            Purpose            Location

  External Battery        J2         Keyboard plug               J5

  Power LEDs &            J3         Proprietary external        S1
  keylock                            memory bus

  Speaker & volume        J4         EPROM expansion ROMs     U10 & U28
  control

                        USER CONFIGURABLE SETTINGS

              Function                   Jumper/Switch        Position

  »   Factory configured - do not             J1                N/A
      alter.

  »   Power good signal detect from           JP1               Off
      power supply

      Power good signal detect from           JP1                On
      board

      DMA speed select 4MHz                   JP2               Off

      DMA speed select 8MHz                   JP2                On

  »   Monitor type select color               SW1            pins 1 & 2
                                                               closed

      Monitor type select                     SW1            pins 2 & 3
      monochrome                                               closed

  »   NPU 80387 disabled                     SW2/1              Off

      NPU 80387 enabled                      SW2/1               On

  »   NPU 80287 disabled (Version            SW2/2              Off
      A)

      NPU 80287 enabled (Version A)          SW2/2               On

  »   Factory configured - do not            SW2/2              Off
      alter (Version B)

  »   DMA page register mode select          SW2/3              Off
      extended (Version A)

      DMA page register mode select          SW2/3               On
      PC8-standard (Version A)

  »   Video ROM caching enabled              SW2/3              Off
      (Version B)

      Video ROM caching disabled             SW2/3               On
      (Version B)

  »   Fail-safe timer non-maskable           SW2/4              Off
      interrupt disabled

      Fail-safe timer non-maskable           SW2/4               On
      interrupt enabled

  »   IRQ 10 disabled                        SW2/5              Off

      IRQ 10 enabled                         SW2/5               On

  »   IRQ 11 disabled                        SW2/6              Off

      IRQ 11 enabled                         SW2/6               On

  »   IRQ 12 disabled                        SW2/7              Off

      IRQ 12 enabled                         SW2/7               On

  »   CPU speed when accessing               SW2/8               On
      floppy disk select 16Mhz

      CPU speed when accessing               SW2/8              Off
      floppy disk select 8Mhz

  »   Factory configured - do not             VC1               N/A
      alter (Version A)

  »   Factory configured - do not             VC2               N/A
      alter (Version A)

      Notes:If JP2 is not present on main board, JP2 is factory set to
      open, if JP2 is present then JP2 is

      factory set to closed and should not be altered.

      Version B, main boards with part numbers of 150-0006935 and later,
      do not support the 80287.

      Location of 80287 NPU is unverified.

      On Version A main boards with part numbers of 150-0004426 or later,
      SW2/switch 3 controls

      video ROM caching and DMA is always in extended mode.

      If using a third-party video card, video ROM caching should be
      disabled.

      Variable capacitors VC1 and VC2 are present only on Version A main
      boards.

[Image]

                    EXTERNAL MEMORY CARD CONFIGURATION

         Size                    Bank 0                   Bank 1

          1MB                  (36) 41256                  NONE

          2MB                  (36) 41256               (36) 41256

  Note:Location of banks 0 & 1 unidentified. Memory chips are
  unidentified.

                 EXTERNAL MEMORY CARD JUMPER CONFIGURATION

                Size                                  J2

                1MB                  pins 2 & 3, 5 & 6, and 8 & 9 closed

                2MB                  pins 1 & 2, 4 & 5, and 7 & 8 closed

                 EXTERNAL MEMORY CARD SWITCH CONFIGURATION

  Size    SW1/1   SW1/2   SW1/3    SW1/4   SW1/5   SW1/6   SW1/7   SW1/8

  1MB      On      On      On       On      On      On      On       On

  2MB      On      On      On       On      On      On      On       On

             EXTERNAL MEMORY CARD SWITCH CONFIGURATION (CON’T)

  Size    SW2/1   SW2/2   SW2/3    SW2/4   SW2/5   SW2/6   SW2/7   SW2/8

  1MB     Off      On      On       On      On      On      On       On

  2MB      On      Off     On       On      On      On      On       On