Still stupid questions.. I hate to do it, and I really appreciate your patience (so far).. The first more complex xsub I need, now looks like this (it's not terribly good, nor functional.. also some bad comment added):

int
dx_playf(chdev, fnamep) /* must put tpt here, and am .still. not clear
+ */
    int chdev
    char *fnamep
    PREINIT:
        DV_TPT tptmp[2];
    CODE:
    /* Will the constants below be worked out of the
       headers, which are included above in the XS?
       I've seen lots of ways of getting them to Perl,
       but perl does not need them */
       tpt[0].tp_type   = IO_CONT;    /* the next entry is next on arr
+ay */
       tpt[0].tp_termno = DX_IDDTIME; /* Interdigit Delay */
       tpt[0].tp_length = 2;
       tpt[0].tp_flags = TF_IDDTIME;

       tpt[1].tp_type   = IO_EOT; /* last entry */
       tpt[1].tp_termno = DX_MAXDTMF; /* Maximum digits to get from ca
+ller */
       tpt[1].tp_length = 1;
       tpt[1].tp_flags = TF_MAXDTMF;

        RETVAL = dx_playf(chdev, fnamep, tptmp, 0);
    OUTPUT:
        RETVAL
[download]

The DX_TPT struct is defined in the header:

typedef struct DV_TPT {
           unsigned short   tp_type;             /* Flags describing t
+his entry */
           unsigned short   tp_termno;           /* Termination Parame
+ter number */
           unsigned short   tp_length;           /* Length of terminat
+or */
           unsigned short   tp_flags;            /* Parameter attribut
+e flag */
           unsigned short   tp_data;             /* Optional additiona
+l data */
           unsigned short   rfu;                 /* Reserved          
+       */
           DV_TPT           *tp_nextp;           /* Pointer to next te
+rmination TPT */
}DV_TPT;
[download]

and info on all the mad things I must still do with the DV_TPT at http://support.dialogic.com/documentation/unix/SR50_linux/html_files/vox_api/0009c-07-163.html#P18891_490358 This also doesn't have the code to make and destroy memory.. These are the things I still must learn, if I do disclose my experience by other means than my PM experience points.. I envisage wrapping the lot, so I need to make a setter for each type (no need for a getter, it's just for passing args in), correct? I have a problem now that all the simpler functions are failing. -1, and $! = Invalid Argument. the xsubs are:

int
dx_open(chdev, mode)
    const char * chdev
    int mode

int
dx_close(dev)
    int dev

int
dx_sethook(chdev, hookstate, mode)
    int chdev
    int hookstate
    unsigned short mode
[download]

and the following lines in test.pl:

$chdev = Starla::dx::dx_open("dxxxB1C1",0)  or die "Cannot open dxxxB1
+C1 ($!)\n";
print "Device is $chdev ($!), state is ";
$tmp = Starla::dx::ATDX_STATE($chdev);
print "$tmp ($!)\n";
[download]

returns: Device is -1 (Invalid argument), state is -1 (Invalid argument) At this point I wonder how I even managed to do this under some software package under Windows NT. This is about as complex as I will need to get, and feeling like even that's skew. Thanks again.. problem is probably due to a bit of a lack of sleep, which I plan to do now. THis is a learn for me, but if I can make it well enough, not only will I run my server using this extension, I also want to make it my first CPAN module