Modem problem with XP

[Roger Lide]

I have an existing PB3.20 program that runs fine under DOS
and Win 98, but under XP it can't receive data. It opens the
port, dials, and connects OK, but I get no data to my program.
I have the program set for the IRQ listed in the system drivers
but it acts like it is not getting the IRQ.

Thanks,
Roger

[Lance Edmonds]

Unfortunately there is not much to go on here, but the fact the code works on other platforms suggests the problems are either the modem and/or it's configuration, or the OS's settings are not correct.

Firstly, What sort of Modem is it? Also, is this a "Winmodem" or a "real" modem (one that is compatible with plain DOS and not reliant on Windows drivers)? It seems that many PCI modems are winmodems these days.

To test this avenue of thought, can you use the modem successfully with other comms apps, both DOS and Windows? (that is, are you sure the modem is actually working?).



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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[Roger Lide]

Dell says the modem is a "Winmodem", so does this mean I can't
use it with DOS in Windows XP? Device manager reports COM 3,
IRQ 5 at D400-D4FF and DC00-DC7F. Why would a "Winmodem" report
an IRQ unless there is some kind of software UART simulator.
Maybe software like TurboCom would work, but it only works
with Win9x.

Roger

[Lance Edmonds]

The hardware will very likely need an IRQ to work... most expansion cards do require an IRQ to operate so that data can be moved between the card and the PC.

The problem with Winmodems is that there is no firmware in the modem to handle the actual communications (ie, the phone line side of the modem)... the Windows driver does it all, and will likely use proprietary port I/O methods to control the hardware on the card.

This technique is sometimes referred to as "host-based firmware".

Windows comms apps will work with the modem since they will use the driver to drive the modem... something that a DOS application cannot do.

Therefore your best solution is to open the case, unplug the Winmodem, fit a real modem, reassemble the case, and configure the new modem accordingly.

Sorry!

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[Tom Hanlin]

It's possible to write a driver that provides a virtual hardware
interface under Windows. If the manufacturer has gone to the effort,
a Winmodem could work fine in DOS sessions under Windows. However,
Winmodems are intended to keep costs to a minimum, so it would not
be surprising to see cost-cutting on driver development, also.

------------------
Tom Hanlin
PowerBASIC Staff

[Roger Lide]

Tom,

Yes, the driver issue is the problem. I have 2 machines with
Windows 98 that run it fine. They have DOS support on the
system driver (provided by Pacific Commware "Turbocom VIP").
With this is enabled, Windows reports an IRQ in system drivers.
XP does not have a DOS support tab under system drivers, but
shows an IRQ anyway, so I assumed that the driver was part of XP.
Where would XP come up with an IRQ if there is no hardware or
software to produce it?

Since my problems are with newer laptops, maybe I'll try adding a
card modem and not use the internal. Or better yet, maybe it's
time for me to try PBCC!!!

Roger