-----Original Message-----
From: Dennis Chuah <[EMAIL PROTECTED]>
To: Multiple recipients of list delphi <[EMAIL PROTECTED]>
Date: Monday, 10 May 1999 10:47
Subject: RE: [DUG]: NT Terminal Server
>
>Tony,
>
>> If your application uses Serial Port comms, then most likely you are in
>> for a very rude shock.
>
>With WinFrame (similar to Terminal Server, but NT3.51), the only client
that
>supports serial comms is the DOS client.
Yes I know. Sadly the customer is not prepared to go with Meta Frame.
Instead, NCD (The vendor of this particular terminal hardware) have a
software layer called Thinstar Plus
which is supposed to redirect incoming comms away from serial.sys to there
own vendor specific serial driver. It works like this.
NT configures the devices in the registry and the driver associated with
them
as a symbolic link in the registry. When a Win32 call is made to a serial
port
the Win32 subsystem determines what driver to pass the call to by looking it
up
in the registry. Normally, this will be serial.sys, however the
registry is configured under NT so that any reference to a virtual com
device opens NCD's
netcomm.sys driver instead. In this driver they have implemented all of the
same
IOCTL functions supported by serial.sys, and mapped them into network
communications with the client serial service on the thin client terminal.
So, if anything comes into the Win32 subsystem requesting interaction with a
com device which they have mapped in the registry to a thin client,
netcom.sys
receives the requests rather than serial.sys, and supposedly redirects the
traffic.
Thats the theory... Unfortunatly anything I write in Delphi redirects
outgoing comms OK, but Incoming comms always acts as if it is arriving from
the Server port.
I have tried writing my own serial comms using Borlands Windows interface
unit ie Standard Win32 PI calls, and also Async Pro with identical problems.
A straw clutch was to "steal" MSComm32 from MS C++ for a quick test, but
here I have run into these licensing issues which I haven't got back to just
yet. It's too much work, and I am not familiar enough with Vis C++ to re
write the entire application.
Interestingly, Hyperterminal works fine on the NCD hardware. My programs
which work fine on any other Win32 platform do not. I don't beleive that any
comms program written in D4 with conventional Serial Comms archetecture will
work.
Any ideas wellcome.
Cheers,
Tony.
>
>Dennis.
>-----------------------------------------------------
>Dennis Chuah, BE (Hons) [mailto:[EMAIL PROTECTED]]
>Manager, Product Development
>Contec Data Systems Ltd. [http://www.contecds.com]
>tel: +64-3-3580060 ext-775 fax: +64-3-3588045
>
>
>
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