Thanks all for trying to help. Final solution at the end of this post.
To Edwin...the parameter settings for the 5000L-G and 5020L control are not the same as the 5000L green screen control. The 5000L only has one page of settings for parameter word, long word, and parameter bit.
Gosiger was able to get the machine to punch out a program but still could not send from PC to machine through RS232. They suggested a new communication board. Luckily, I have a spare LC-20 parts machine that has been scavenged over the years so I took the RS232 communication board out of it and installed on other machine...fixed my problem.
With the help of our DNC software vendor we were able to get the machine to READ a program through RS232 (using TT as Duke mentioned). BUT, like Gosiger cautioned, we were losing characters. We went all the way down to 300 on the baud rate with no luck and different handshake settings. It was pretty consistant with the character loss. The DNC vendor even put a few millisecond pause between each character for the transfer but it didn't help.
Here's the solution...a $1500 solution...works perfect.
I purchased a BTR through
Advanced Digital Research
Very easy to install. Emulates the tape reader and works like RS232 at 9600 baud.