In message <001101c0703c$70393580$260bf6cd@pc>, Olin Lathrop
<olin_piclist@EMBEDINC.COM> writes
>> Any version of Delphi later than 1.0 (that is, any 32 bit version)
>> doesn't allow you to access the hardware directly (version 1.0 had the
>> Port() procedure) - so in order to do so you have to write a small piece
>> of in-line assembler code - this is freely available on the net, and
>> consists of a handful of op-codes. This then reads the port directly,
>> and doesn't wait for Windows to give permission - which is why it's not
>> included in 32 bit Delphi.
>
>This won't work on all versions of Win32, and is very hardware specific.
>The Win98 virtual machine might trap the reference and eventually do it for
>you, but addressing protected memory on NT simply won't work.

Yes, it won't work on NT, you must use a driver (I use DLPortIO.DLL),
but it works fine under 95, 98, and ME.

>The right way to do this is to write a parallel port device driver that
>performs the operations you want, then call it thru the official CreateFile,
>ReadFile, WriteFile, etc, interface.

But that slows everything done massively, this thread was about reading
data via the parallel port being slow!.
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Nigel.

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