This isn't really travel related, but I didn't know a better place to put it. My dad's dental office has a phone system that was installed in the early 90s. To program it, you connect it to the serial port on your computer - though when it was installed he actually connected it to the RS232 port on his antiquated WYSE 50 terminals.

Now he's trying to connect it to his Dell desktop, which has only parallel and USB ports. I bought a USB to DB9 adapter. Windows recognizes it and assigns it COM4. I set PuTTY to 1200 baud, 7 data bits, no parity, 2 stop bits, which is what is written on the phone system data jack. I also set the USB adapter to those settings on its property page in the device manager. Dad says this has always worked on his WYSE 50 terminals, but I can't get any response from the terminal. Does anyone have any ideas?

The USB adapter I bought is a TrendNet TU-S9.

I use a USB to serial all the time to connect to routers from my laptop. 1200 seems low. By default with most any device (barring instructions to the contrary), I go with 9800-N-8-1. Also, I'd try Hyperterm instead of Putty - it's available as a download for Vista and Win7 from www.microsoft.com/downloads.

I realize the phone system data jack says 1200-N-7-2, so possibly putty isn't set to COM4?

Nope, it is set to COM4 (I mean, I typed "COM4" in the Port setting). I've also tried Hyperterminal. I'm wondering how the settings for Putty and the driver need to work together...in the Device Manager there is a property page with all the same settings for the port. I have tried setting the port and Putty to 1200 N72...and I've tried Software, Hardware, and No flow control.

I think I may have too many adapters - the USB has a DB9 male adapter, which has an adapter that converts it to DB25, which has an adapter to the RJ25 cord. I ordered an RJ25 to DB9 adapter...hopefully it will do the trick. I'm fresh out of ideas!

You're probably right about one too many adapters. In 28 years in the business, I've had screwy connectors that changed 9 to 25 and back again at the other end of the cable, with a gender change or two in there somewhere. Sometimes it works, sometimes it just doesn't.

In my computer bag, I carry a SIIG USB-serial cable as well as a Cisco serial-ethernet to attach to it. Works every time.

There's also the possibility that you'll need a null modem cable if the terminal was set up in an unusual way. (Null modem means that the wires for receive and transmit are swapped. So, if it's set up such that it's using a null modem configuration you'll need an additional cable in there. Think they're available at radioshack still...)

Great suggestion, I may still have a breakout box somewhere that was used to see which line is transmit.

I have a KeySPAN adapter dongle. One thing about it is it needed a driver update for Windows to properly work with it even though it recognized it, so, you might want to see if yours needs something special.