Mark,

>>Without seeing more code showing all the containership - impossible to tell ;-) I'll hazard a guess:
>>
>>THISFORM.ComReader.WhateverTheControlNameIs.INPUT
>But in that case I am talking to comm control directly.
>Why then do I need EVENTHANDLER at all?

Notice my checking for the COMMEVENT=2 - this event signals that data is available in the INPUT buffer and needs processing. Without EVENTHANDLER, you would be limited to polling the port with a timer or user action of some sort. With EVENTHANDLER, you are binding your code to the event and it will run only when the event occurs. Also note there are a number of other subevents of ONCOMM that may require action on your part - most notably errors. If you are interested, I can email you a VCX that may clarify what I'm saying.