control number of output character in 1 frame

hi,i'm new here..
i need to create the database to save for my serial MSComm output.
i wanna know how to determine max character in one frame can my textbox
display from my output serial port,since each frame in raw data from my serial port had 50 character,and i needed to save 50 character in my access database.
did each frame had its limit character contain in it,??
if not how do i set my character about 50 for every frame out in textbox in one time.....???
i really2 appreciate it if you can help me to solve my problem!!!!!