Teletype 43

Ethan Dicks ethan.dicks at
Mon May 22 20:41:08 CDT 2017

On Mon, May 22, 2017 at 2:16 PM, Paul Koning via cctalk
<cctalk at> wrote:
>> On May 22, 2017, at 1:44 PM, Jim Brain via cctalk <cctalk at> wrote:
>> OK, go ahead and roll your eyes at me, but I was Dayton Hamvention last weekend,
>> and there was a lonely Teletype Model 43 sitting in the flea market (on the ground, no less)
>> for free, and so I decided I needed it in my life.

No eye-rolling here.  Nice find!

>> I got home last night, and the unit fires up and works (well, in local mode.  Docs claim
>> it is rs232 out the back, but could not coax anything from my PC to it yet),

Do you have a "traffic light"?  I find them invaluable for diagnosing
handshaking and TxD/RxD swaps.

> Does your PC have real RS232?  A lot of "RS232" ports are serial ports, but not with correct
> RS232 levels.  If you have "TTL RS232" [sic] it won't work with an actual RS232 port.

If you are testing from a laptop, this could be it.  Some years back,
I joined our local hackerspace, in part, to get some life out of a
Bridgeport Series II (driven by an M7264 KD11-F processor board) and
after building my own round Tyco serial cable because the former owner
of the Bridgeport was, in his own estimation, no good at soldering,
was initially unable to get any commands to work from my Linux laptop
from a "real" serial port or from a USB dongle.

What worked was a serial port on a desktop.  The first try.

I do know, from examining the boards when we scrapped the Bridgeport,
it uses the ancient and venerable 1488/1489 pair.  I've seen those
work with "modern" serial ports, so I'm unsure why this device had
problems, but it did.  No dongle or laptop tested was functional with
the Bridgeport.


More information about the cctalk mailing list