Document 1308
GATE A20 and Printing
BPT
2/7/92

Description:  

286, 386, 486 machines may have a problem printing if their BIOS
Setup has the ability to enable GATE A20. If the port seems to
hang as though the printer is off line, then GATE A20 may be the
problem.

GATE A20 indicates protected mode is already in use.  Some
motherboards have been found to set GATE A20 as active.  If so,
it will conflict with ANY protected mode program such as the
EMM386.SYS driver that comes with DR DOS 6.0 with the result
that the LPT port may hang.

Often, there is a solution in the BIOS SETUP (usually accessable
just as the machine runs its memory count).  Many BIOS Setup
menus allows you to turn off GATE A-20. The type of printer is
not relevant, nor the video or CPU.  Newer version motherboards
do not automatically set the GATE A20 on and will therefore work
correctly.


Example:      

ERROR: (pin A-20 already set), or the machine hangs when trying
access the parallel port. 

	Enter BIOS Setup and disable GATE A20.