Why in VDM a COM program do not work?

[Leonardo De Palo]

Hi friends of BP,

this is the mine first post to this forum.
I'm writing from Italy, near Roma.

I have monitored this list from few days ago.

I have been discovered the Power Basic for the first time
a couple of months ago. As an old entusiast programmer of
the use of Turbo Basic ten years ago, After that positive
experience, the world goes to VB...

Now I have buied the full line of product of Power Basic
and I have in plan to use it frequently!

But at my first approach to the serial port, a strange problem
put me in trouble.

A simple comm program, that work fine under pure DOS, in a
VDM (DOS)windows of WIN98SE do not work.
The program is:

DEFINT a-z
CLS
$COM 1024
OPEN "COM2:9600,n,8,1,DS,RS,CS,CD" as #2 LEN = 1024
PRINT "premi un tasto per terminare"
WHILE NOT INSTAT
DO UNTIL LOC(2) = 0 or EOF(1)
a$ = INPUT$(1,#2)
PRINT a$;
LOOP
WEND

What I have mistaked?

Thanks for your answer.

Ciao

Leonardo

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[Lance Edmonds]

EOF(1) looks wrong since you have not opened file #1...

This little app seems to be just listening to a serial port. Other than the EOF(1) problem, what happens? Is there actually a data stream to be read?


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

[Leonardo De Palo]

You have reason, the statement is caming from an older file...

The working programa is:

defint a-z ' integer variables are smaller and fast
CLS
$COM 1024
OPEN "COM2:9600,n,8,1,DS,RS,CS,CD" as #2 LEN = 1024
PRINT "premi un tasto per terminare"
WHILE NOT INSTAT
DO UNTIL LOC(2) = 0 or EOF(2)
a$ = INPUT$(1,#2)
PRINT a$;
LOOP
WEND
CLOSE
END

and this program show incoming serial data only if is
made running in COMMAND PROMT mode.

Starting the same program under a windows DOS, the
windows remain black. Do not appear the
"premi un tasto per terminare"

regards

[Lance Edmonds]

If you step through the code with the debugger using the F7 key, does the OPEN statement appear to work, or does it hang? Try adding $ERROR ALL ON to the code and see if any errors are detected when the code is run.

Is COM2 configured correctly in CONTROL PANEL (port address, IRQ, etc)? Have you set the Properties of COM2 in CONTROL PANEL|SYSTEM|COM/LPT PORTS to use RTS/CTS handshaking, etc?

Is there a conflict with COM2 and some other device you have installed (like an internal modem or other device)? In some cases, Plug & Play hardware can cause a port or IRQ conflict with "legacy" devices like COM ports - since DOS does not "enable" these devices, the conflict may not show up until Windows is running. Check the "Resources" tab on the Properties sheet for COM2

If you use "Hyperterm" (which comes with Windows), does that show the data stream arriving on COM2?



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

[Leonardo De Palo]

Hi Edmonds,

stepping through the code with the debugger using the F7 key,
stay highlihted on yhe does the OPEN statement
OPEN "COM2:9600,n,8,1,DS,RS,CS,CD" as #2 LEN = 1024
forever.
I have found an older mu TB program that use the serial port
with tree wire, GND, TX and RX and have the following OPEN:

OPEN "COM2:9600,N,8,1,CS,DS" AS #2

and with this new open the program continue to not run.
I will try to adding $ERROR ALL ON to the code and see if
any valid errors are detected.

Using Hyperterm, I can see the correct data incoming trought
the COM2.



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[Leonardo De Palo]

Hi

In CONTROL PANEL, COM2 have port address,02F8 - 02FF,
IRQ 3, flux control ia at none.

Regards


Leonardo


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[Lance Edmonds]

Well, since the OPEN statement is "failing", you must have a serial port problem. Try to listen to the port with Hyperterm and see if that works.

Also, try opening the port with the default settings...

OPEN "COM2:9600,n,8,1" as #2 LEN = 1024

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

[Leonardo De Palo]

Hi,

I believe that I have a problem.


Using Hyperterminal I receive the data correctly.


Now I will try to another PC to see if the problem change..,


Ciao


Leonardo

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