interfaceing to ancient TRS-80 model 100 portable

[Hendrik Boom <hendrik@pooq.com>]

I have inherited an old Tandy TRS-80 model 100 portable computer.
What Debian software do I use for this.  No ... I/m not trying to put 
Linux on a Basic-only machine.  But it hase a serial port to 
upload/download data and programs -- but I have no documentation.
I can probably get it to pipe stuff out as a serial stream, of possibly 
ancient stuff like Xmodem.

Does anyone have actual experience with these things?

-- hendrik