What is the cheapest way to add 2 or 3 serial ports to Sun 3/60

[Andrew Chan]

We just bought a used Sun 3/60 for a good price.  We would like to add 2
or 3 serial ports (in addition to the 2 that are already there) CHEAPLY.

Would you please kindly give use some pointers to what/where to look for?
I think ALM-2 cards (I think it has 8 ports?) has more than what we
need....

Much thanks... e-mail or post as you see appropiate