Serial I/O Device Driver
John Dobbs
jdobbs at mwunix.mitre.org
Tue Oct 16 06:17:56 AEST 1990
I am looking for some advice concerning DOS device drivers. I have written
a serial i/o port driver (AUX) in assembly language. It is installed by
DEVICE = xxx.sys and handles the RS-232 port on an interrupt basis. I can
successfully access the driver directly from C language routines as in
fgets( string, MAX_CHARS, stdaux)
or
fputs( string, stdaux ).
The problem I have is in redirecting stdin to aux as in
c:> someprog < aux
By monitoring what the driver is receiving versus what DOS is giving to
someprog, it looks as though there is double buffering or non-recognition
of end of line in that the characters received are out of sync. The
documentation I have described the template of a device driver but not the
buffering that might be done by DOS. Can someone give me a hint of what
might be happening?
Thanks,
John
jdobbs at mwunix.mitre.org
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