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       # NCR CORPORATION
       
          CLASS 3421
       
          Processor       80386SX                                        
          Processor Speed 20MHz                                          
          Chip Set        NCR                                            
          Max. Onboard    8MB                                            
          DRAM            
          Cache           None                                           
          BIOS            AMI                                            
          Dimensions      381mm x 254mm                                  
          I/O Options     Serial port, parallel port, PS/2 mouse port,   
                          SCSI interface (2), floppy drive interface,    
                          CPU upgrade slot, proprietary SIMM sockets (3) 
          NPU Options     80387SX                                        
       
   IMG IMG 1
          
       
          +------------------------------------------------------------+
          |                        CONNECTIONS                         |
          |------------------------------------------------------------|
          | Purpose          | Location | Purpose           | Location |
          |------------------+----------+-------------------+----------|
          | Video controller |   CN1    | IDE/floppy drive  |   CN8    |
          |                  |          | power             |          |
          |------------------+----------+-------------------+----------|
          | Internal SCSI    |   CN2    | FS1 header        |   JP1    |
          | interface        |          |                   |          |
          |------------------+----------+-------------------+----------|
          | External SCSI    |   CN3    | SCSI terminating  | R1, R2,  |
          | interface        |          | resistors         |    R3    |
          |------------------+----------+-------------------+----------|
          | Serial port      |   CN4    | Proprietary SIMM  | S1, S2,  |
          |                  |          | socket            |    S3    |
          |------------------+----------+-------------------+----------|
          | Parallel port    |   CN5    | MCA slot          | S4, S5,  |
          |                  |          |                   |  S6, S7  |
          |------------------+----------+-------------------+----------|
          | PS/2 mouse port  |   CN6    | CPU upgrade slot  |    S8    |
          |------------------+----------+-------------------+----------|
          | Floppy drive     |   CN7    |                   |          |
          | interface        |          |                   |          |
          |------------------------------------------------------------|
          | Note: Pin 1 locations unverified.                          |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                     DRAM CONFIGURATION                     |
          |------------------------------------------------------------|
          |  Size   |  Bank 0   |     S1     |     S2     |     S3     |
          |---------+-----------+------------+------------+------------|
          |   2MB   |    2MB    |    NONE    |    NONE    |    NONE    |
          |---------+-----------+------------+------------+------------|
          |   4MB   |    2MB    |  (1) 1M x  |    NONE    |    NONE    |
          |         |           |     18     |            |            |
          |---------+-----------+------------+------------+------------|
          |   6MB   |    2MB    |  (1) 1M x  |  (1) 1M x  |    NONE    |
          |         |           |     18     |     18     |            |
          |---------+-----------+------------+------------+------------|
          |   8MB   |    2MB    |  (1) 1M x  |  (1) 1M x  |  (1) 1M x  |
          |         |           |     18     |     18     |     18     |
          |------------------------------------------------------------|
          | Note: Bank 0 factory installed and is not configurable.    |
          | Locations and individual chip sizes for Bank 0 inside DRAM |
          | area are unknown.                                          |
          +------------------------------------------------------------+