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More Wacky Fun on COM 1!

Posted on 1999-07-11
Medium Priority
Last Modified: 2010-04-27
Question by:Dean Peterson
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Expert Comment

ID: 1871974

Believe it or not, a lot of the newer motherboards are sensitive to the ribbon cables. If you don't use the cables that come with the motherboard you can have this problem.

FIC motherboards are like this. If you used the original cables try swapping for the new ones. Pull the I/O card and reactivate the on board Com ports first.


Accepted Solution

Spax earned 800 total points
ID: 1871975
 1. In your bios, can you disable individual com ports? If so, is COM1 disabled? If it is, enable it and reboot.
 2. Check your connection to the motherboard and make sure the red wire on the ribbon cable is on pin 1. Red always goes to pin one. If it isn't, turn the connector around and reboot. (Be sure your power is off while fiddling with the cable.
 3. Check your mouse on another computer to be sure the mouse is good.
 4. When installing windows be sure to tell windows the correct mouse type. If your telling Windows to expect a bus mouse when it's a serial mouse it can give you heaps of difficulty. (Same thing with ps/2 mice)
 5. If your motherboard has jumpers instead of a bios screen, ensure your jumpers are correct to allow COM 1 to operate.
 6. If your having to use an IO card, your bios may be trying to use the COM 1 port anyway, be sure the bios has the onboard COM 1 disabled if your using an off motherboard IO card.
 7. Check to make absolutely sure no other hardware on your computer is using the mouse IRQ. I believe IRC4 is used for com1 and IRQ3 is com2 (but I may have those switched around in my head).
 8. Return the motherboard to where you purchased it and exchange it for another identical board.

Try 8 last. :) Seriously, there isn't much else an expert would try before 8. If you can't fix it before reaching 8, then your putting more time into the problem than a paid professional would. Hope this helps.

Expert Comment

ID: 1871976
 Heh, not to mention some of the newer motherboards come with ribbon cables that have those nifty little black plastic ridges on the floppy drive connector. Heh, darn if I didn't have to snip that puppy off as my floppy drive had a reversed connection. :) Silly manufacturers.

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