Gee, nobody has talked about the ASR33 in a while...

Well, as I reorganize and clean, I managed to sidetrack myself from the aforementioned cleaning by playing with my ASR33 TeleType. I have it working properly, and it prints and types correctly - although I have never managed to interface it to anything. I remember a year ago, trying some quickie kludge I found on the 'net, and having it not work. I am struggling to remember what I thought I used to know about TeleType interfaces. Correct me if I'm wrong: The teletype's serial output is compatible with RS232 at the protocol level, and since it's a 33, it's ASCII too. The TeleType is a passive device with a 20ma current loop interface. In order to work, it needs a loop current source (I had to use a 9v radio battery for testing) The signal levels, being 20ma current loop, are NOT compatible directly with RS232C. That being said, it's seemingly possible in some circumstances to interface the two with a diode and a resistor and have it work. In interfacing this thing, I basically want to be able to construct a simple device that 1) supplies loop current, 2) optically isolates the current loop from the RS232 host, and 3) provides proper RS232 signal levels (MAX232, what a wonderful little chip) so that I can connect it to whatever without worrying about blowing up the transceivers. I should be able to scrounge up some optoisolators, I know I have MAX232's and I should have no trouble constructing a simple, transformer based power supply to supply power for both the MAX232 and the loop current. But, I have forgotten some key elements, such as I don't know what an acceptable voltage is to supply the loops, and although I remember reading that the RX and TX used different amounts of juice, I don't remember the specs, and lastly - AC or DC loops? DC, right? What's an acceptable way to create loop current without driving something too hard or blowing something up? Also, my TeleType manual doesn't appear to have information on what screw terminals do what on the terminal strip at the back of the machine - I think I remember which ones were RX and which were TX, but I would like to be sure. It's late... I am bound to have something horribly wrong in my mind (and therefore in this post) right now. Any help would be appreciated. Thanks! -Ian