Re: Serial!

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Re: Serial!

        James Hall <jrhall@INFOCOM.COM> writes:

> I got to thinking while at work today, What about connecting a
> UART chip (for a serial port) to an unused address on the bus?!
> Then we wouldn't have to worry about figuring out how to duplicate (or worry
> about paying for) a graphlink for connection to a modem!
> (and we could have different baud rates too!)
> Of course we would have to rewrite any term programs to use the special
> address but what do you think?

I think this would be one of the more useful additions to the
calculator.  It should be relatively easy to connect the databus and a
few control wires to a UART by creative wiring.  Ofcourse, we should
settle on one design if at all possible, so here is what I see as the
initial design issues:

 1. Is there an address bit that could be used as a chip select, saving
    extra logic?

 2. Which UART chip?

 3. Where does the baudrate clock come from?

 4. Electrical interface of serial port to be RS232 (+-12V) or TTL?

 5. Which additional serial control wires?

 6. Choice of connector?


An even more fundamental question:

    What would people use the serial port for?

--
Manfred Bartz <mbartz@werple.net.au>
--------------------------------------------------------------
Would you put the worlds best wooden wagon wheels on your car?
Then why buy 56k anti-technology?
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