Notes on MO stuff
1. MO.SYS and MO.TSX are built from MO.MAC 
2. Use SET MO VECTOR=xxxxxx  
   and SET MO CSR=xxxxxx
   to set the correct values in both TSX and RT.
3. MOTALK sends its one line input to the MODEM
4. HHEXEC uses a phone directory on ND:NDIAL.NUM
5. No COMPUSERVE protocol is supported in HHEXEC
6. ^W only local at this time in HHEXEC
7. If two terminals use HHEXEC the line cannot be used again by TSX