
IBM CORPORATION

PS/1 TYPE 2133A, 2155A, 2168A (TYPE 1)

Device Type        Mainboard
Processor          80486SX/80487SX/80486DX/80486DX2/P24T
Processor Speed    25/33/50(internal)/66(internal)MHz
Chip Set           Unidentified
Video Chip Set     Unidentified
Maximum Onboard    64MB
Memory
Maximum Video      Unidentified
Memory
Cache              128/256KB
BIOS               Unidentified
Dimensions         330mm x 218mm
I/O Options        Floppy drive interface, IDE interface, parallel port,
                   PS/2 mouse port, serial ports (2), VGA feature
                   connector, VGA port, riser slot
NPU Options        None

[Image]

                                CONNECTIONS

  Purpose                   Location   Purpose                   Location

  PS/2 mouse port             J2       VGA feature connector       J14

  Serial port 1               J3       IDE interface LED           J26

  Serial port 2               J4       Speaker                     J27

  Parallel port               J5       Power supply connector      J29

  VGA port                    J6       Power supply connector      J30

  Floppy drive interface      J7       Riser slot                  SL1

  IDE interface               J9

                        USER CONFIGURABLE SETTINGS

               Function                    Label           Position

     On board video disabled               J15        Pins 1 & 2 closed

      On board video enabled                J15        Pins 2 & 3 closed

     Factory configured - do not          SP103         Unidentified
      alter (password bypass)

     Factory configured - do not           U53          Unidentified
      alter

                            SIMM CONFIGURATION

     Size         Bank 0         Bank 1         Bank 2         Bank 3

     1MB        (1) 256K x        None           None           None
                    36

     2MB        (1) 256K x     (1) 256K x        None           None
                    36             36

     3MB        (1) 256K x     (1) 256K x     (1) 256K x        None
                    36             36             36

     4MB       (1) 1M x 36        None           None           None

     4MB        (1) 256K x     (1) 256K x     (1) 256K x    (1) 256K x 36
                    36             36             36

     5MB       (1) 1M x 36     (1) 256K x        None           None
                                   36

     6MB       (1) 1M x 36     (1) 256K x     (1) 256K x        None
                                   36             36

     7MB       (1) 1M x 36     (1) 256K x     (1) 256K x    (1) 256K x 36
                                   36             36

     8MB       (1) 1M x 36    (1) 1M x 36        None           None

     12MB      (1) 1M x 36    (1) 1M x 36    (1) 1M x 36        None

     16MB      (1) 4M x 36        None           None           None

     16MB      (1) 1M x 36    (1) 1M x 36    (1) 1M x 36     (1) 1M x 36

     17MB      (1) 4M x 36     (1) 256K x        None           None
                                   36

     19MB      (1) 4M x 36     (1) 256K x     (1) 256K x    (1) 256K x 36
                                   36             36

     20MB      (1) 4M x 36    (1) 1M x 36        None           None

     24MB      (1) 4M x 36    (1) 1M x 36    (1) 1M x 36        None

     24MB      (1) 4M x 36    (1) 2M x 36        None           None

     28MB      (1) 4M x 36    (1) 1M x 36    (1) 1M x 36     (1) 1M x 36

     32MB      (1) 4M x 36    (1) 4M x 36        None           None

     33MB       (1) 256K x    (1) 4M x 36    (1) 4M x 36        None
                    36

     48MB      (1) 4M x 36    (1) 4M x 36    (1) 4M x 36        None

     52MB      (1) 4M x 36    (1) 4M x 36    (1) 4M x 36     (1) 1M x 36

     64MB      (1) 4M x 36    (1) 4M x 36    (1) 4M x 36     (1) 4M x 36

                    CACHE CONFIGURATION

     Size          Bank 0         Bank 1          TAG

     128KB      (4) 32K x 8        None       (1) 32K x 8

     256KB      (4) 32K x 8    (4) 32K x 8    (1) 32K x 8

                  CACHE JUMPER CONFIGURATION

        Size                 J16                  J17

        128KB          Pins 1 & 2 closed   Pins 1 & 2 closed

        256KB          Pins 2 & 3 closed   Pins 2 & 3 closed

                     VIDEO MEMORY CONFIGURATION

  Note: The size and location of the video memory is unidentified.

                   CPU TYPE SELECTION (SX SYSTEM BOARDS)

        Type                J23               J24               J25

       80486SX           Pins 1 & 2        Pins 1 & 2        Pins 1 & 2
                           closed            closed           closed

    486SX/80487SX        Pins 1 & 2        Pins 1 & 2        Pins 2 & 3
                           closed            closed           closed

    486SX/ODP486         Pins 1 & 2        Pins 1 & 2        Pins 2 & 3
                           closed            closed           closed

  486SX/Pentium ODP      Pins 1 & 2        Pins 1 & 2        Pins 2 & 3
                           closed            closed           closed

                CPU TYPE SELECTION (DX, DX2 SYSTEM BOARDS)

       Type               J23                J24               J25

      80486DX          Pins 1 & 2         Pins 1 & 2        Pins 1 & 2
                         closed            closed             closed

     80486DX2          Pins 1 & 2         Pins 1 & 2        Pins 1 & 2
                         closed            closed             closed

    Pentium ODP        Pins 1 & 2         Pins 1 & 2        Pins 2 & 3
                         closed            closed             closed

