I have a program I'm trying to use to drive a scoreboard of 4 7-seg LEDs. The brand is Sure Electronics and the controller board came with code to communicate via HyperTerminal. (Commands are on p10 at http://www.sure-electronics.net/down..._Ver1.0_EN.pdf) These commands work fine and drive the digits as they're supposed to. However, I want to drive them from my VB.Net program, not from HyperTerminal. I have done this successfully with another brand, and thought I knew about what was needed, but my little demo program doesn't work. In it, I have tried to do 3 things using 3 buttons: set up the com port, send 8 as a test digit to all four digits (their addresses are 1,2,3,4), and turn off all the digits. I know the com port routine works, because I've used it before. (I have set up the com port to the same specs as what works in HyperTrminal.) I tried two slightly different approaches for the other two items, but neither works. I am confused about what needs to be ASC and what doesn't. Any help appreciated! My code is attached.