Hi all,
Thanks again for your responses about the RS232 to current loop converter set up. As you know I got it working but now I have a question about a symptom I am experiencing, and I am curious if you think I have diagnosed the problem correctly.

Question #1 - If when using an RS232 converter to connect from the Altair 680b to an asr33 teletype, should the 680b motherboard jumper be set for 1 stop bit or 2? In other words, the converter is irrelevant, set as if the Altair was throwing a current loop?

I understand that the teletype is 2 stop bits. That's why I assume the answer is yes. Does anyone here have a 680 running off a teletype than can speak from experience on the matter?
7 / mark / 2 stop (text transfer)

Question #2 - Currently I have the 680 jumpered for 1 stop bit / 110 baud. I did this first to see what happened because it was already at 1 stop bit for regular terminal / serial comms. Would having the Altair 680 board set for 1 stop bit cause occasional errors when reading in a long papertape? This is what I have been experiencing.

NOTE - when I connect the 680 directly to a serial terminal using 110b I can load in MS Basic papertape image just fine with the Altair jumpered to 1 stop bit. Is this because in the serial connection scenario the Altair stop bit jumper should be set to 1?

NOTE 2: The teletype I believe is OK. It can read in papertapes without issues from other machines.

I plan to switch the 680 from 1 stop bit to 2 unless I hear a convincing argument not to. It's really not a big deal for me to experiment, but I try to avoid re soldering the board unnecessarily.

Thanks in advance