A/B switch to cross switch mod file

Lately, in my packet/phone modem/8bit home computer (with modem software that
can store and load from disk) system, I added a VT100 terminal I got at a 
hamfest.  This will let me view stuff using 80 characters across the screen, 
instead of always having to use the 40 characters the home computer does.  
Before I got the terminal, I used an A/B RS232 switch that switched all 25
wires.  Now, to accomodate the terminal, I need a switch that can select 
connections of 8bit to TNC, 8bit to modem, terminal to TNC, and terminal to
modem.  A cross connect switch.  Which would cost something like $25.  I
decided to see if I could modify the A/B switch.  I use software Xon/Xoff
flow control, which needs only 2 active lines and a ground.  So, I need only
switch 2 lines.  Looking at the '89 ARRL Handbook, page 19-28, table 15), it
shows the functions of all 25 RS232 wires.  The ones I use are pin 2, TxD, 
and pin 3 RxD.  Also pin 1, protective ground, and pin 7, signal ground.  But
there is a secondary TxD, called STxD, pin 14, and a secondary RxD, called
SRxD, pin 16.  So, I figured, I would connect the TNC to the common of the
A/B switch, to the primary TxD and RxD.  And connect the phone modem to the
secondary TxD and RxD.  (I would need to make a special Y shaped cable to
do that.)  And connect the 8bit machine to the primary TxD and RxD of the
A connector of the switch, and the VT100 to the primary signals of B.  

   Here's the mod to make this work:
Wire a jumper from the A connector pin 2 (TxD) to B's pin 14 (STxD).
Another jumper from A pin 3 (RxD) to B pin 16 (SRxD).
And another from B pin 2 (TxD) to A pin 14 (STxD).
And a last jumper from B pin 3 (RxD) to A pin 16 (SRxD).
I also shorted all pin 7's together, and shorted all pin 1's together.
(This avoids switching spikes in the grounds that might glitch the equipment.
  
   Now make the Y cable:
pins 2 and 3 of the "common" connector go to the TNC connector pins 2 and 3,
respectively.
Pins 14 and 16 of the "common" connector go to the phone modem connector pins
2 and 3, respectively.
All pin 1's are connected, and all pin 7's are connected.

Label the modified A/B switch to describe what you did, so you don't try to
use this switch to switch printers or something years later.  

My switch was an Inmac, with all original wiring traces on a circuit board.
All mods are added jumpers, and no cut traces.  So, this switch could be
restored later if I need to.