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From: klos@bcrvmpc3.vnet.ibm.com (Marty Klos)
Newsgroups: comp.os.os2.programmer
Subject: OS/2 device drivers
Message-ID: <9104112254.AA26109@ucbvax.Berkeley.EDU>
Date: 11 Apr 91 22:54:38 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Lines: 20

References: <1991Apr09.151935.19325@lut.fi>

I know that in IBM C/2 (MSC 5.1),  the i/o routines were
already in a separate segment in the large model libraries.
You could access them by using a .def file to the linker
containing the line:

   SEGMENTS '_IOSEG' CLASS 'IOSEG_CODE' IOPL

Although I haven't used MSC 6.0, I would suspect it still works.
Try looking in the .map file for your program that uses inp or outp.
If you see 'IOSEG_CODE', then this should work.

Beware, there is a performance hit (vs DOS) because every call
to an IOPL routine from a non-IOPL routine goes through a call
gate.  Also, be aware that you will need the function versions of
inp and outp, not the *intrinsic* (translation: in-line)
versions.

Marty Klos/Internet: klos@vnet.ibm.com