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From: cowan@marob.masa.com (John Cowan)
Newsgroups: comp.os.os2.programmer
Subject: Re: DOS driver under OS/2
Keywords: device driver
Message-ID: <27442249.D19@marob.masa.com>
Date: 16 Nov 90 17:30:49 GMT
References: <478@epicb.com> <1990Nov15.160926.5036@cbnewsk.att.com>
Distribution: na
Organization: The Logical Language Group, Inc.
Lines: 17

In article <1990Nov15.160926.5036@cbnewsk.att.com>,
	dez@cbnewsk.att.com (daniel.e.zuccarelli) writes:
>[An OS/2 device driver]
>must be a bi-modal (both real and protected mode) driver if you plan
>on calling it from the DOS box (which runs in real mode).

This statement is too weak.  An OS/2 driver must be bi-modal whether it
is called from the compatibility box or not, because it will have to 
service real-mode interrupts that come in when the >user< is running the
compatibility box.

The only thing that can be omitted from an OS/2 driver not used from the
compatibility box is the real-mode (DOS-compatible) calling sequence,
which is usually trivial to provide.
-- 
cowan@marob.masa.com			(aka ...!hombre!marob!cowan)
			e'osai ko sarji la lojban