[Simh] Problems with the B5500 simulator

[Paula Ash]

I'm currently trying to run the B5500 simulator on Mac OS Mojave and
when I try to use the Datacom lines, I see the following error
messages before it crashes when I'm trying to use Telnet to connect to
it:

"sim_debug() formatted result: 'Datacomm transmit 0 76 '
            has an imbedded \0 character.
DON'T DO THAT!
Abort trap: 6"

If it helps, I'm currently using the Mark XIII MCP tape images that
are available for the retro-b5500 emulator project and the
instructions on sky-visions.com.