I have access to three laptop computers but none has an old-fashioned nine-pin "D" serial connector. This is a connector that looks a lot like a VGA connector, except that it has only nine pins instead of the VGA connector's 15 pins. Anyway, I bought a car-testing gizmo that requires a nine-pin serial port (sometimes called an "RS-232" port) and thought for sure that one of my laptops had such a connector.

None did. The only option was to get a USB-to-serial adapter and the only way in my area to get one of those quickly was to go to Radio Shack. I did try other stores and they had things that were tantalizingly close, but none had a cable with a standard USB connector on one end and a standard nine-pin connector at the other end. Radio Shack did -- it is part number 26-123 at Radio Shack -- and it costs $35. It looks just like the picture at the top of this review.

What it is

The Radio Shack 26-123 USB-to-serial adapter is a beige cable about six feet long with a standard USB connector at one end and a male nine-pin "D" connector at the other end. A few inches from the nine-pin connector is a beige plastic box about half the size of a deck of cards molded onto the cable. There is nothing to adjust or select anywhere -- there are no switches or controls of any kind and no batteries are required. The nine-pin connector is encased in a heavy plastic molding and it has two integrated screws that can be used to attach the connector tightly. It turns out that I really can't use these attachment screws in my application, but that proved to be no problem.

The package also comes with a CD-ROM disk with drivers and a manual. Everything looks like it is well made and professional, which is not always true of Radio Shack products.

Installing it

It's just a cable, so you'd think all I'd have to do would be to plug it in at both ends and sail off into the sunset. Few things are that easy. The Radio Shack 26-123 USB-to-serial adapter first required that I load drivers from the supplied CD onto my Windows XP laptop. To its credit, loading the drivers was simple and straightforward. The disk fired up properly on my computer and selecting the right one was a no-brainer. The driver loaded quickly with no errors. There are drivers for Windows XP/ME/2000 and 98.

Only then could I plug the USB connector into my computer, which did the normal handshaking for a new USB device. Within 20 seconds or so, my computer had located the correct driver and was ready to use the Radio Shack 26-123 USB-to-serial adapter.

Using it

With one end of the USB-to-serial adapter plugged into my computer, I attached the nine-pin end into the car-testing gizmo and followed the instructions to make sure everything was communicating properly. I was a little surprised to find that everything was communicating perfectly. My usual experience with stuff like the Radio Shack 26-123 USB-to-serial adapter is that things inevitably need to be tweaked, adjusted and de-bugged before the magic happens. However, everything -- including the USB-to-serial adapter -- worked perfectly.

I plugged the car-testing gizmo into the OBD-II test port on my car and ran the associated program. My laptop showed all sorts of interesting things happening in my car, including the speed, engine RPM, fuel flow, spark advance, coolant temperature, O2 sensor readings and a host of other useful troubleshooting information. With the laptop on my lap, my wife drove the car and I watched the readings for the intermittent problem that has been bedeviling us with this particular car. I don't have the problem isolated yet but that's not the fault of the Radio Shack 26-123 USB-to-serial adapter. It has worked perfectly during this process.

Summary

The Radio Shack 26-123 USB-to-serial adapter is a little expensive. I was expecting such a device to cost around $25 instead of the $35 that the Radio Shack unit costs. However, it appears to be well-made, its drivers were easy to install, its on-disk documentation is very good and it has worked perfectly without any hiccups or tweaking. Other than taking the time to buy and install this adapter, it has not slowed down my work in the least.

If the Radio Shack 26-123 USB-to-serial adapter cost $25, I'd give it five stars. As it is, I'm rating it down just a bit because it's a little expensive. Otherwise, it has worked perfectly and does exactly what it says it does.

I recommend the Radio Shack 26-123 USB-to-serial adapter.

Recommended: Yes