Date: Wed, 18 Sep 2013 21:31:53 +0200
From: jdr_use at bluewin.ch
To:
Subject: Re: PDP-8/L current loop -> RS232 help
On 09/15/2013 02:19 AM, Josh Dersch wrote:
> Hi all --
>
> I'm attempting to get my 8/L talking to the outside world. It's outfitted
with the typical Teletype interface, which I'm attempting to connect to a PC via
acurrent loop to RS232 adapter.
>
> Specifically, I've got one of these:
http://www.bb-elec.com/Products/Serial-Connectivity/Serial-Converters/Curre….
>
---snip---
Depending on how you want to use it, you can have 1 or 2 current loops.
With nothing sent, 20ma is correct. It should go to 0ma for each data
bit, not 40ma.
If you make one loop, just use the supply in the 33. If you have
2 loops, another supply should be used.
1 loop for no echo and 2 if the computer echos what you type.
Check the specifications for your adapter.
Dwight