Article View: comp.os.os2.programmer
Article #453Re: IOPL summary
From: joe2
Date: Fri, 24 Jul 1992 18:43
Date: Fri, 24 Jul 1992 18:43
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1180 bytes
In <4063@news.duke.edu> Jan Gittelman writes:
>Summary on IOPL
>
>1. IOPL'd code has to be 16 bit, can't be 32 bit. So for that matter do device
> drivers. All 2.0 device drivers according to IBM are 16 bits.
>
There is another undocumented (yet?) way on OS/2 2.0 : provided
that TESTCFG.SYS is installed, you can use this driver for simple
I/O : use DosDevIOCtl, Category 80h
1) FOr an IN instruction : function 41h
Parameter packet:
USHORT io_address
USHORT data_width (1 for byte, 2 for word, 4 for dword)
Data packet:
ULONG value(value read)
2) For an OUT instruction: function 42h
Parameter packet:
USHORT io_address
USHORT data_width
ULONG value
No data packet
Hope this helps!
-Joel Armengaud
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Path: arc1-ca.pugleaf.net!sparky!uunet!vnet.ibm.com From: joe2@vnet.ibm.com Message-ID: <19920724.095122.977@almaden.ibm.com> Date: Fri, 24 Jul 92 18:43:06 FST Newsgroups: comp.os.os2.programmer Subject: Re: IOPL summary Reply-To: <joe2@vnet.ibm.com> Disclaimer: This posting represents the poster's views, not those of IBM News-Software: UReply 3.0 References: <4063@news.duke.edu> Lines: 33