Coin-In Jam and a Mystery I/O Cabinet Card

[Stayouttadabunker]

I know, I know...."Coin-In Jams" are nothing new but I wanted to point out something I saw today that I'm having a hard time remembering about.

As I was swapping out I/O cards in an effort to find out which card was bad, I swapped out a cabinet I/O card.
These cards have the "short" pin connections....unlike the I/O cards such as 801 with the long housings that have a lot more pins.

Anyways, as I'm swapping out the cabinet I/O with different cards I had in a box, Id be booting up my S2000 and get the "Coin-In Jam" error then put the non=working I/O aside for inspection later.
Then I finally found one that worked and it was a "200" I/O card and the "Coin-In Jam" error went away.

I took the three cards that didn't work and brought them over to my bench to remove the metal cover so I can see the component-side of the I/O cards.
I usually spot a burned out ceramic fuse on these things from when someone installed/pulled out a card while powered up.
I was surprised that all the pins were straight, the fuses were all okay, and no components looked burned out or exploded?
That's when I looked at the label and saw that these cards were NOT "200" I/O cards - instead, they were "601" I/O cards.
Yep...dummy move I did! 

Okay, this is the part where I need help....
I've forgotten.. haha...what in the world are the "601" I/O cards used for? 

[Retro tech repair]

Trimline avps have a similar io card to the s2000 not sure the number tho.

[Stayouttadabunker]

okay thanks.
I actually have a few of those machines on the floor...I'll have to go pull one out of one for comparison.