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Re: Apple IIc+ modem connector

rg.jones@rogers.com wrote:

Hi,

bieling@terra.es wrote:


Yes, that's rare.
But if the reason why you asked is that you're thinking about some sort
of serial port-based gadget, 5v can be easily obtained from the
*external* serial connectors as long as the current needs are not too
high.



Was looking at doing something inside the IIc+ - I searched and found I
can use http://www.maxim-ic.com/appnotes.cfm/appnote_number/3534 to
convert -5v to +5v or leech it off something else close by to get +5v.


Or you could treat -5v like ground and ground like +5v.  This would
no doubt mean level-shifting the Tx/Rx lines, but otherwise should
work fine.

If you need +5v, it would be a lot easier inside the case to just tap
into +5v.


If it's true that they are "like the Macintosh serial ports" as I've
read in the tech ref. manual, just a few diodes a capacitor and a
series regulator should be enough to get 5v and tens of milliamps...



I was hoping that I could connect the modem port directly to a PIC for
example and forgo the usual MAX232 (driver/receiver).


Yes, that should work fine.

-michael

Parallel computing for 8-bit Apple II's!
Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it is seriously underused."