[E3-hacking] Universal E2/E3 serial interface design

[Andy]

Hiya,

As per my earlier posting I've now designed and built a universal E2/E3 
interface board that should convert to/from legal RS232 levels. A jumper 
is used to select E2 or E3 mode. I've also produced a circuit diagram 
from my prototype and put this here:

http://www.cambridgewargames.org.uk/members/andy/emailer/

I would welcome any feedback on the design and would also appreciate 
people sanity check I've not put any stupid mistakes in the circuit 
diagram when copying from my stipboard prototype.

    Have a good weekend,

          Andy M