Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!dali.cs.montana.edu!milton!sumax!thebes!polari!arcade!kenr
From: kenr@arcade.uucp (Ken Reneris)
Newsgroups: comp.os.os2.programmer
Subject: RE: 16-Bit Device Driver + OS/2 V2.0
Message-ID: <500.510@arcade.uucp>
Date: 25 May 91 07:51:29 GMT
References: <9105191848.AA16778@grape.ecs.clarkson.edu>
Lines: 24

| It is my understanding and experience that if you have a 16-bit device driver
| that uses 'documented interfaces', e.g. DevHelp calls, it should work on
| V2.0 without modification.  ...

Most drivers will work.  However, there may be some which won't work
and will need rev'ed.  With OS/2 2.0 there are new DevHlp's to handle
memory as list of pages (rather then selectors).  If a 2.0 level driver
locks some pages within a particular selector down, then an old device
driver may not be able to lock the same memory with an old style DevHlp_Lock.
To emulate the old style lock, the kernel collcects all the pages in the
selector, lies them out contigously in memory and locks them.  (Even for
a short term lock).  Anyway, if all the pages can't be made contigous
(since a page within the selector is locked by someone) the DevHlp_Lock
will fail. (even for a short term non-blocking lock).

I would also suspect any driver which did something in the 3xBox won't
work in an MVDM without changes.  :^).

On the up side - there's no more dual-mode DD model.

	    - Ken

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