[Coco] An X-10 usage for the Direct Connect Modem Pak

George Ramsower georgera at gvtc.com
Mon Aug 17 23:27:27 EDT 2015


  Phone lines are unbalanced. The means there is no ground. The tip is + 
and the ring is - . This protects the phone company and the same is true 
on all broadcasting audio lines and a heckuvalotta of other electronics.
  If one device has a different ground potential than the other, a 
balanced circuit is necessary.
  You can't win this scenario. Play it safe, ground both phone lines to 
be safe or use another connector where the phone jack was/is.
  Never assume no one will plug it into a phone jack. However, since it 
most likely will be used by the person who can modify it for your 
purpose, it's not likely they would connect it to a phone line. But in 
time... memory fades or the ownership can change. I expect anyone that 
buys this setup, would not know.
  My guess is that if someone was lucky enough to get MY coco stuff, 
they would not even know what to do with all the mods I've made to the 
"system". The coco itself is basically stock but all the plug-ins are not.
  If I pass away, all this would end up in a recycling center. Even my 
brother wouldn't want it and wouldn't know where to sell it, if he had 
the time.>>> recycle bin.
  I only personally know of a couple people that even vaguely remember a 
Coco.

  Consider all this dumb stuff. I don't, because I know after I'm 
gone... >>> recycle bin is where it's going.

George R.

On 8/17/2015 10:00 PM, K. Pruitt wrote:
> I think the Tip line functions as a ground. Well at least in regular 
> phone systems. I'll take it slow. I'd hate to fry a CoCo.
>
> ----- Original Message ----- From: "George Ramsower" <georgera at gvtc.com>
> To: <coco at maltedmedia.com>
> Sent: Monday, August 17, 2015 7:49 PM
> Subject: Re: [Coco] An X-10 usage for the Direct Connect Modem Pak
>
>
>>  You will have to cut the phone line pair and use one or both of 
>> those wires for a ground. The DTR and CTS lines do need a ground. 
>> Then, the phone jack is totally useless for anything else. However, 
>> using the two center pins as a ground will eliminate the possibility 
>> of destroying the pak and the possibility of killing a coco.
>> George R.
>>
>> On 8/17/2015 9:42 PM, K. Pruitt wrote:
>>> I used my zap utility and just changed the addresses to look at the 
>>> DC modem pak. I just didn't change it everywhere.
>>> Honestly I'm surprised it worked at all.
>>>
>>> Only two of the 4 wires in that 4 wire connector are even used. 
>>> Yellow and blue are unused. So they are wide open for use and can be 
>>> easily jumpered to the DTR and RTS pins on the 6551. I'm fairly 
>>> certain even I can pull this one off. Not quite mod-free, but a 
>>> really easy mod.



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