Setting up COM ports?



captain-kirk (149) on 02/04/99 at 15:40:52 PST

wild-willie: com ports are somewhat difficult to setup. It can involve both your BIOS and windows resource manager. You really need to find out what port addresses and IRQs the modem is looking for.

"com3" is basically a bit of a misnomer, in that it really doesn't mean anything in and of itself. Generally, com1 and com3, when stated that way, means that they share an IRQ - IRQ 4 I think (might be 3). The idea, though, is that anything that shares an IRQ has to be not used at the same time. In other words, I have my mouse on COM1, set to irq 4. However, my modem is on IRQ7, since I don't want it sharing with the mouse (I want to use my mouse and the internet at the same time). Find what irqs are in use (go to your control panel -> system -> device manager and click on properties) and what IRQs the modem can use, and you need to make sure that the modem's is free (or shared with something that will never be used at the same time).

The second part of the puzzle is the port address. This is probably what they mean when they say "com3". my com1 is 03F8, my "com4" is 02e8. My modem is on 03E8. The trick is to give everyone unique addresses - no sharing!

One thing you may need to do is to go into the BIOS and disable your second physical com port (or whichever one(S) you're not using. Windows will reserve resources for those ports, so if you're not using them, disable them.

Once you do that, and install your modem, you can play in windows with the resources. Go to control panel -> system and click on the various COM ports, mice, and modems, and see what resources they show. You can change them manually.

This is not an easy task, hope I've given you some hints.

..back..