How to test COM1

Question

I transferred files and programs from an old computer (386SX) to a new Dell. I connected a controller timer (RadioShack X10) to the serial port (COM 1). When I started the X10 software, I got a message that read

"Check the interface connections. The Software is programmed for COM 1."

The connections are ok. But to make sure, I reconnected to the serial port (COM 1) of the 386SX and everything worked fine. After reconnecting back to the serial port of the Dell, it still did not work. The same message appeared.

I tried rebooting, still no luck.

So I know the software works, I know the connections are ok.

How do I check the serial port on the Dell to make sure it is working?

What is the best strategy to get the timer:controller up and running?

Jim Hardin · Answer

John: What on earth is a controller timer and what is it used for????

Comming from a 386SX, I doubt that your software was written for Windows. It is probably trying to talk directly to the comm port and may be looking in the wrong place.

Check in Device Manager to see what your comm port is numbered. If it is Comm 1 see what the I/O range is. Then see if you can find what I/O range your software needs.

JMELO · Answer

Jim,

Thanks for responding.

An X10 timer controller is a device for sending on-off signals through the eletric wires in your house. It has 2 wires: One is a serial cable to the computer. The other is an electric plug. The computer is used to program times that you want on and off signals to be sent through the plug. It sends the signal to a timer module, a small device that plugs into an outlet. The piece of equipment that you want to turn on and off plugs into the module.

It is usually used for household security, but I use it to control pumps and lighting in a tropical fish room.

I am not trying to run the software in windows. I am trying to run it in DOS mode. My serial port is designated COM 1, and I designated COM 1 during the setup of the X10 program.

I checked I/O range as you suggested (03F8-03FF), however, I am unable to find a specification in the files. I don't have the original documentation.

If I run it in dos mode why isn't it finding the COM port. How about the baud rate?

Jim Hardin · Answer

I am not an expert in these things... I would guess: 1. That the comm port may have to be enabled in BIOS in order for it to work in MSDOS mode. 2. That the software is trying to write directly to the comm port I/O (common in DOS programs) but the I/O is not where it expects it.

A poor solution would be to retain that ole 386 to do that job alone...

Maybe some serial wizard will jump in here.

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How to test COM1

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