does your pos terminal also have a printer? also does the cashdrawer have a rj11 socket behind it similar to a telephone wire? if so you can connect your casdrawer directly to the printer and from your software send a command to the printer to open up the cashdrawer.
Here is a company that maybe of help to you... www.[URL="http://www.personasystems.com"]http://www.personasystems.com[/URL]personasystems.com i think the website is under construction at the moment. but they do also help with techniqal questions. hope it helps
So why not ask your suppliers for some assistance? There really should be no reason in this day and age to need to drop to assembler code to get a till to work. Surely there has to be a more convenient way?!