Xref: utzoo comp.sys.amiga.tech:5794 comp.misc:6393
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!bionet!apple!sun-barr!sun!pepper!cmcmanis
From: cmcmanis%pepper@Sun.COM (Chuck McManis)
Newsgroups: comp.sys.amiga.tech,comp.misc
Subject: Re: Serial Help
Message-ID: <112065@sun.Eng.Sun.COM>
Date: 23 Jun 89 18:46:35 GMT
References: <637@bnr-fos.UUCP>
Sender: news@sun.Eng.Sun.COM
Reply-To: cmcmanis@sun.UUCP (Chuck McManis)
Organization: Sun Microsystems, Mountain View
Lines: 29

In article <637@bnr-fos.UUCP> protcoop@leibniz.uucp () writes:
> I now have two things that require connection to my serial port ...
> I would like to build a switch box so that I can connect both devices 
> to it and JUST FLICK a switch to select one.

There are several ways to do this, the easiest is to buy one :-), but 
building them is fun too. The simplest way is to get a giant 7 X 3
rotary switch. And wire the port from the Amiga to one pole (using the
7 modem lines, TD, RD, DTR, CTS, RTS, GND, DSR ?) And two mounted 
DB25 connectors to the other two poles. Following the conventions of
pin2 to pin2, pin3 to pin3, etc. This will build your basic switch.
Now the various manufacturers have created a market for a PCB mounted
25 X 4 switch that lets you do all the wiring with a simple two sided
Printed circuit board. These have the advantage that they switch all
25 lines so that you can put a MIDI interface or something on one of
the outputs and it will still be powered by the Amiga. Finally, for
the really fancy folks, you can convert the RS232 levels to TTL and
then build a logic based switching network. Using this method I once
designed (but never built :-() a 16 input serial box that would let
you connect any port to any port and change the gender of the output
connector on the fly (DTE or DCE) plus by hooking a bunch of LEDs up
to any of the internal busses you could monitor activity on that bus.
[TTL designer goes wild, film at 11:00] 


--Chuck McManis
uucp: {anywhere}!sun!cmcmanis   BIX: cmcmanis  ARPAnet: cmcmanis@sun.com
These opinions are my own and no one elses, but you knew that didn't you.
"A most excellent barbarian ... Genghis Kahn!"