🚀 go-pugleaf

In article <477k6r$b8q@oban.cc.ic.ac.uk>, djbur@ic.ac.uk (Mr D.J. Burbridge) writes...
>In article <31OCT199522341928@erich.triumf.ca> bennett@erich.triumf.ca (P.Bennett) writes:
>>
>>You will have no direct control of the serial data lines, pin 2 or 3.  There
>>are a few controllable pins, if you can write directly to the UART control
>>register, but the levels will be either +12 or -12 - not 0 or +5.
> 
>Is this the case on a PC? I know the RS232 *used* to be +/-12V, and the
>RS423 was introduced as a +/-5V version, but I thought RS232 these days was
>also +/-5V? Certainly (as I believe I have mentioned in this group before
>:-)) I can connect my PC's RS232 to my BBC's RS423 with no (apparent)
>problem (yet...)

I think the RS-232 spec calls for voltages between 5 and 15 volts, or so, but
most receiver circuits actually have a threshold of +1 volt or so, so the
driver doesn't have to actually go negative - a 0 - +5 input will usually work.

Peter Bennett VE7CEI                | Vessels shall be deemed to be in sight
Internet: bennett@triumf.ca         | of one another only when one can be
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