This topic discusses the switches as defined for IBM logoed PCs only.  On
PC-compatible computers, there may be more or fewer switches and they may
have different meanings.

The IBM XT has a single bank of DIP switches.  They are summarized as
follows:

SW1 (XT)
ON  1 2 3 4 5 6 7 8 
                   
                 
                  7-8: diskette drives
                  5-6: initial active display monitor
                  3-4: system board RAM
                  2: 8087
                  1: POST loop (always OFF)

Positions 2,5-6,and 7-8 are the same as on the PC. See PC Switch Settings

  XT RAM  
The XT POST determines the total system memory by scanning RAM address
space to locate 32K blocks (it displays numbers in the top left corner of
the screen as it does this).  Therefore, you do not need to change switch
settings when you add or remove memory option cards.  Moreover, you need
not populate the system board fully (above 128K) to add additional memory
option cards.

Switches 3-4 indicate the memory on the XT system board as follows:

SW1 (XT)
ON  1 2 3 4 5 6 7 8 
                     128K
                 
ON  1 2 3 4 5 6 7 8 
                     192K
                 
ON  1 2 3 4 5 6 7 8 
                     256K
                 

See Also: Equipment List
- -

XT Switch Settings