A simple reminder: Numbering in Linux starts with 0. So for example, if you have 2 serial ports on your computer, they are ttyS0 and ttyS1. So to ask if you can place a Synth on ttyS4 implies that you have 5 serial ports on your computer. I haven't necessarily answered your question, but make sure that you are counting correctly before you try to connect and then get frustrated because you are not counting correctly. Steve Dawes Phone: (403) 268-5527 Email: SDawes at calgary.ca NOTICE - This communication is intended ONLY for the use of the person or entity named above and may contain information that is confidential or legally privileged. If you are not the intended recipient named above or a person responsible for delivering messages or communications to the intended recipient, YOU ARE HEREBY NOTIFIED that any use, distribution, or copying of this communication or any of the information contained in it is strictly prohibited. If you have received this communication in error, please notify us immediately by telephone and then destroy or delete this communication, or return it to us by mail if requested by us. The City of Calgary thanks you for your attention and co-operation.