Microsoft KB Archive/34192

IBM PC/XT Motherboard Switch Settings: Display Adapter PSS ID Number: Q34192 Article last modified on 09-23-1991 PSS database name: PSS

Summary:

The IBM PC/XT series of computers have switches on the motherboard to determine the system configuration. If these switches are set incorrectly, erratic errors can result.

More Information:

The display adapter installed in the system is indicated by the setting of switches 5 and 6 on Switch Block 1 as follows:

Display Adapter          Switch Block 1

---                          : 1 2 3 4 5 6 7 8 :                           :                 : on IBM Monochrome/Hercules   :                 : :                :                           :         x x     : off ---

---                          : 1 2 3 4 5 6 7 8 :                           :           x     : on CGA (40 Column)           :                 : :                :                           :         x       : off ---

---                          : 1 2 3 4 5 6 7 8 :                           :         x       : on CGA (80 Column)           :                 : :                :                           :           x     : off ---

---                          : 1 2 3 4 5 6 7 8 :                           :         x x     : on EGA/VGA                   :                 : :                :                           :                 : off --- Copyright Microsoft Corporation 1991.