Teletype 43

Jim Brain brain at
Tue May 23 20:20:17 CDT 2017

On 5/23/2017 1:07 AM, dave.g4ugm at wrote:
> You probably need a null modem cable.
I had one (and used it), but not all null modem cables are evidently the 
same :-)  I soldered up a loopback as you suggested, and the unit 
dropped into DATA MODE on startup.  I then played with the signals.  The 
unit really does want DCD to be active, as just doing CTS/RTS, DTR/DSR, 
and RX/TX did not do the trick.  Evidently, my null modem cable I had 
tested with previously does not connect DCD. Swapped out for a null 
modem adapter (from our old now deceased friend Radio Shack) and the 
unit works with a new Dell M4800 laptop (so "newer" style +-10V RS232 
levels must be OK.

I appreciate the brain dusting.  I should have known to try that, as I 
spent years doing serial stuff and wrote tcpser, the Hayes Modem 
emulator package for Linux/Windows.  I even have a Telnet BBS cable 
named after me.  Sigh...

The printer ribbon has less life left in it than I anticipated, but a 
list member is helping me, so it should be good to go after a deep 
cleaning and a light oiling.  I did notice the printhead starts to 
stutter at times on long lines, but I *think* it's a function of the 
damage to the ribbon, so we'll troubleshoot that only if it continues 
after ribbon fixes.

The broomhandle looks to be working fine, but if there's a spare paper 
roll pin and/or a platen knob out there looking for a home, let me know.


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