protcoop@leibniz.uucp (06/21/89)
This problem does not relate directly to the Amiga, but it is technical and I do own an Amiga ... besides, I didn't know where else to post it. I now have two things that require connection to my serial port (modem and X10 controller) and this is a problem. 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. Unfortunately I do not really know how I can do this. My first thought was to use a couple of multiplexer chips and multiplex each line ... but I am not sure if that will allow two way communication. Also, this would require each line to be multiplexed. Do all the lines have to be switched? Can I just make each line connect to both ports and just have one line multiplexed ... say a certain line that tells the device he has the port. Is there such a line on my serial port? I read the description of the pin-outs but did not know what some of the pins meant. I would appreciate any input into this. Thank you. ---------------------------------------------------------- Alan W. McKay | My opinions are mine, yours are yours. | Eat Food | NEPEAN, Ont. | I in no way pretend to represent the | and | 613-763-8980 | the options of my employer. So there. | LIVE !! |
pnelson@antares.UUCP (Phil Nelson) (06/23/89)
In article <637@bnr-fos.UUCP> protcoop@leibniz.uucp () writes: >I now have two things that require connection to my serial port >(modem and X10 controller) and this is a problem. 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. Unfortunately I do not really Assuming I didn't just go out and buy a switch (they are sort of spendy), I would use a 4-pole double-throw switch to switch TD (pin 2), RD (pin 3), DSR (pin 6) and DTR (pin 20) connect pin 7 to both devices. In some cases you can get by with a double pole double throw, simply omit the DSR and DTR, connect DTR to DSR on any device that cannot be strapped to ignore them. I like to have them though, I like my modem to hang up when I drop DTR, either when I close the serial port, or Amiga gurus, or, in your case, when you throw the switch and disconnect it. >meant. I would appreciate any input into this. Thank you. You're welcome, I hope it's not too redundant. >---------------------------------------------------------- >Alan W. McKay | My opinions are mine, yours are yours. | Eat Food | >NEPEAN, Ont. | I in no way pretend to represent the | and | >613-763-8980 | the options of my employer. So there. | LIVE !! | -- Phil Nelson at (but not speaking for) OnTyme:NSC.P/Nelson Tymnet, McDonnell Douglas Network Systems Company Voice:408-922-7508 UUCP:{pyramid|ames}oliveb!tymix!pnelson LRV:Component Station "What we face is government troops and we have no guns." -Chinese student
jwright@atanasoff.cs.iastate.edu (Jim Wright) (06/23/89)
In article <637@bnr-fos.UUCP> protcoop@leibniz.uucp () writes: | 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. Unfortunately I do not really | know how I can do this. Buy a switch box. About $12 will get you a two position switch box with all 25 lines switched. Not the best in the world, but the price is right. Plus, it can even be used for the parallel port. (I got several from CompuAdd.) -- Jim Wright jwright@atanasoff.cs.iastate.edu
cmcmanis%pepper@Sun.COM (Chuck McManis) (06/24/89)
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!"
ckp@grebyn.com (Checkpoint Technologies) (06/24/89)
In article <637@bnr-fos.UUCP> protcoop@leibniz.uucp () writes: > >I now have two things that require connection to my serial port >(modem and X10 controller) and this is a problem. I would like to >build a switch box so that I can connect both devices to it Alan, Why not get a serial expansion card? -- that is, if you have a 2000. c^2