2 Different Serial Pinouts?!

After upgrading my 486 to a new motherboard which benched a little better and had PCI slots, I found the board had an issue where the Serial ports weren’t working… or did it?

Before giving up hope and putting my old motherboard back in, I figured I may as well research it and see if anyone else has had a similar issue from this era of machine and lo and behold- apparently Serial connectors have (at least) two different pinouts from motherboard or i/o card headers. No standardization on a standardized port? Strange indeed.

At any rate, I quickly started digging through some i/o cards I had laying around to find a connector on one that had this oddball pinout. Here are some examples of some cards showing the two different types. I had no clue as I’d never really needed to pay that much attention before.

I threw the connector cable on my new motherboard and voila! The port worked! The only issue was this cable was just a bit too short to reach the port hole on the back of my case from where the motherboard header was, so I figured what the heck- I’ll just mod my existing cable- this is what I do anyway, right?

De-soldering first-

Using the correct pinout for reference below-

All ready to rock!


Who would have thought?

Having a working box that you can use a mouse on is always a bonus.



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