I use an old DOS version of procomm to talk to these machines.
Do you know how to set the baud rate on the ERS board?
Is K10 unplugged from the ERS and just hanging there?
Are you useing pins 5,6,7, and 8 on the local port?
ALT P settings are:
8 data bits
2 stop bits
x on/x offenabled
When doing a page up for upload, I believe I use the ASCII Transfer (if I remember correctly).