[Elecraft] EC2 KPA100 separate amp monopolize RS232?

[Guy Olinger, K2AV]

Folks,

Just bought K2 #1239 from a gentleman on west coast. He's only giving
it up (sadly) because of failing vision, no longer able to see the LCD
display. So I've adopted it.

Am adding KBT2, KIO2, and the A-B mod kit to the K2.

Considering constructing the matching box 100w "feet" from an EC2,
KPA100, KAT100, and a switching power supply disassembled and
reconstructed to fit.

I understand it has to connect to the K2's RS232. Will that monopolize
the RS232 so it cannot be used with a computer program (remote,
contest, etc) when it is hooked up? Or does it use pins from the DB9
that are not used for computer serial port exchange?

My intent is to use the box as feet and power supply from home, and
switch on the amp as needed. I would just unplug the K2 for portable
operation. The internal battery is a really useful feature, and will
likely be used more than the amp.

Would certainly appreciate some off-reflector communication from
someone who has done the 100w box project.

73, Guy