matt weber wrote in
:

On Mon, 24 Jan 2005 03:38:39 -0500, starman wrote:

That's strange. Why would they not have designed it with an RS-232
interface?
Because RS-232 levels require voltages that are rarely seen on
transistorized equipment these days. Just about everything except
RS232 run on 3.3 or 5 volts. RS232 levels are + and - 10 volts or so,
and 20ma current loop is often about 100 volts!

Chips like the Max232 exist to deal with precisely this problem...


That answers my question as well. I knew not to do it, though I did not
understand why they choose TTL levels. Thanks

Soliloquy