I have used EE for topic, please change it OT if you feel this does not
belong here.

I have a friend who is trying to access the IrDA port on a Radix unit, the
manufacturer sent him a C code example; however, he is coding in Pascal.  I
know C but not Pascal.  The C code uses function pointers and if there are
any ideas how to convert it to Pascal I will appriciate it.

This is the definitions:

enum {
    /* normal application use */
    C_OPEN=1,C_CLOSE,C_READ,C_WRITE,C_GCTL,C_SCTL,C_GSPD,C_SSPD,C_STAT,
    C_DISCOV,C_IASREQ,C_CONN,C_DISC,
};

typedef int (FAR *FPI)();

static char sig[] = "RadixIrDA";
FPI comm_entry = 0L;

The FPI is giving him the trouble.  Below is the function to find the
function:

/*
 * locate IrDA interrupt and save entry point in comm_entry
 */
static int find_irda(void)
{
    int i;
    void FAR *p;
    char FAR *s;

    if (comm_entry != 0) return 1;      /* already located */

    for (i=0x60;i<=0x67;i++) {          /* else look for it */
        p = MAKEFAR(0,(i<<2));
        if ((s = *(char FAR * FAR *)p) != 0L) {
            if (!strcmpf(s+3,sig)) {
                comm_entry = (FPI)s;
                return 1;
            }
        }
    }
    return 0;
} 

The confusing lines are:

p = MAKEFAR(0,(i<<2));
if ((s = *(char FAR * FAR *)p) != 0L)

After this function is called, they use the following functions to access
the port:

int IrDA_open(void)
{
    if (find_irda()) {
        hport = comm_entry(C_OPEN);
    }
    return hport;
}

int IrDA_recv(int portid,char *buffer,int len)
{
    if (portid != hport) return -1;
    return comm_entry(C_READ,portid,(char FAR *)buffer,len);
}

They are accesing the comm_entry with different number of parameters which
confuses him.  I have told him that comm_entry is a function pointer and the
first parameter points to the actual function, comm_entry is not a function
itself.  I hope this is correct.

Any pointers are appriciated,

Regards, Omer

_______________________________________________
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist