NOTES: (THIS IS THE NEW "ONECHIP VERSION" OF SIO2PC.)

There is one integrated circuit, all of the little triangle symbols belong
belong to it.  The 232 sections convert TTL logic (Atari)
to RS232 logic (PC) levels and vice versa.

Atari SIO connector pin #'s are given on the left.  The colors are what I
find when I cut a standard SIO cable in half.  The pin #'s on the right are
for the PC's serial port connector.  The colors are arbitrary. For some
troubleshooting, here's what I find when the interface is plugged into the
Atari but not the PC: (with respect to ground)
Pin 2 of PC connector:  -9.4 volts (approx)
Pin 9 of PC connector:	-9 volts;  Pin 2 of 232: +10 volts;
Pin 6 of 232: -10 volts; Pin 16 of 232: +5 volts
Pin 15 of 232: 0 volts
                                              ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
   1 2 3 4 5             2 4 6 8 10 12        ³WARNING: BUILD AND USE THIS ³
    6 7 8 9             1 3 5 7 9 11 13       ³DESIGN AT YOUR OWN RISK!    ³
  View of the rear      View of the SIO       ³ACCEPT ALL RESPONSIBILITY OR³
of the DB-9F connector  jack on the Atari     ³DO NOT BUILD THE INTERFACE  ³
for the serial port of  console.              ³OR RUN THE SOFTWARE!        ³
the PC.                                       ³                            ³
                                              ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ
         SIO2PC SCHEMATIC pg 3 of 3