Parallel port access

clickmemail

Hi all

I need to write code in VC++ 6.0 on Win2K to send a string to a multiplexer connected to the parallel port LPT1. I could not figure out how to do this as the basic C functions outp and inp work for bytes, not strings! I am lost here! Can anyone help?

Thanks a heap!

melissa_may1

: Hi all
:
: I need to write code in VC++ 6.0 on Win2K to send a string to a multiplexer connected to the parallel port LPT1. I could not figure out how to do this as the basic C functions outp and inp work for bytes, not strings! I am lost here! Can anyone help?
:
: Thanks a heap!
:
:


Hi!

Why can't you loop and send the string one byte at a time? In reality, this is what's hapenning anyway. I mean, you don't send a string to a port, you send a "string" of bytes.

Melissa

adrianxw

: : Hi all
: :
: : I need to write code in VC++ 6.0 on Win2K to send a string to a multiplexer connected to the parallel port LPT1. I could not figure out how to do this as the basic C functions outp and inp work for bytes, not strings! I am lost here! Can anyone help?
: :
: : Thanks a heap!
: :
: :
:
:
: Hi!
:
: Why can't you loop and send the string one byte at a time? In reality, this is what's hapenning anyway. I mean, you don't send a string to a port, you send a "string" of bytes.
:
: Melissa
:

You've got some somewhat larger problems than that I'm afraid. inp and outp are old DOS type calls. VC is a 32 bit compiler, you cannot create DOS code with VC. The later versions of Windows, (I think 2000 is among these), will not allow direct access to a port. You need to talk to the port through the OS. You must get a handle to the port, (look up CreateFile() with particular reference to the Communcations Resources sections), and then use the handle based I/O system calls.



Med venlig hilsen,

Adrian...

miguelgarcia

Try this chunk of code. Works well for me.

void PortCommunicate( HWND hwnd )
{
File *stream;
char buffer[MAX_SIZE];

for (int i = 0; i<MAX_SIZE; i++)
buffer[i] = 1;

stream = fopen("LPT1", "wb");
fprintf(stream, buffer);
fprintf(stream, "
");
fclose(stream);
}

substitute where needed.