Decoding GPS with C#

[C222]

I have a fairly old GPS receiver that communicates with my desktop through COM1.

I found some code on the internet to decode the strings i get from the receiver which look something like:

$GPGSA,A,1,,,,,,,,,,,,,1.27,0.75,1.03*04
$GPRMC,215606,V,3511.1990,N,12904.2725,W,0.000,0.0,151208,15.0,E*45
$PRWIZCH,29,6,12,0,12,0,31,0,24,6,31,0,16,0,31,0,31,0,31,0,31,0,12,0*44
$GPGGA,,,,,,0,00,,,,,,,*66
$GPGSA,A,1,,,,,,,,,,,,,1.27,0.75,1.03*04
$GPGSV,3,1,12,29,70,024,34,24,70,006,39,30,50,190,,21,48,264,*79
$GPGSV,3,2,12,10,34,052,,05,28,173,,18,21,194,,12,20,163,*73
$GPGSV,3,3,12,16,11,321,,31,11,268,,15,09,124,,26,07,108,*73
$GPRMC,215607,V,3511.1990,N,12904.2725,W,0.000,0.0,151208,15.0,E*44
$PRWIZCH,29,6,12,0,12,0,31,0,24,6,31,0,16,0,31,0,31,0,31,0,31,0,12,0*44
$GPGGA,,,,,,0,00,,,,,,,*66

The code if found here.
Using a resource I found on the internet i can tell that the GPS is working and giving me a fairly accurate location (once i get a fix).
However, this is over a terminal application called Tera Term and my GPS requires me to broadcast the command "ASTRAL" before any useful data is sent. The problem is, the code from the link above has no command to submit the command "ASTRAL". I tried:

private void button3_Click(object sender, EventArgs e)
        {
            if (comport.IsOpen)
            {
                //byte astral;
                //astral = Convert.ToByte("ASTRAL");
                comport.Write("ASTRAL");
                comport.WriteLine("ASTRAL");
            }
            else
            {
            }
        }

But that didn't work. Any suggestions?