Thanks for your help with the pinouts, I have to admit
that I got my pin count wrong and have been trying
to use 12 (RTS) instead of 7. Found out by plucking
pins out of a plug until I was sure.

My plug is numbered like this

1 5 9 13 17 21
3 7 11 15 19
4 8 12 16 20
2 6 10 14 18 22

Hope the formatting is retained.

John