I want to use a program like this on a Tandy Model 100:

10 REM COM Port SetUp 9600 8N1??? 
20 PRINT "TRS-80 Model-100 is sending this out!"
30 GOTO 20

I need to know what line(s) to replace line 10 with?

  • I think you may need an expansion interface for the TRS-80. It came with a manual, too. Do you have such hardware included?
    – jonk
    Sep 9, 2022 at 22:21
  • Hi, The Model 100 computer has a RS-232 port on the back, I just want BASIC to send the output from the program out the RS-232 port. No expansion ports should be needed.
    – wperko
    Sep 9, 2022 at 23:06
  • Ah. I did have one. But it was a very long time ago. I seem to recall getting an interface for it and it had a separate manual. My mistake, then. What do you have on the other end of the interface?
    – jonk
    Sep 9, 2022 at 23:07
  • @wperko Please add the information what system that is about as part of the question.
    – Raffzahn
    Sep 9, 2022 at 23:17

1 Answer 1


The BASIC is a rather straight Microsoft 8 bit variant, so just open COM as a file:

10 Open "COM:88N1" FOR OUTPUT AS 1
20 PRINT #1, "TRS-80 Model-100 is sending this out!"
30 GOTO 20

Values are:

  • COM: select the serial port
  • 8 selects 9600 Bd
  • 8 is word length
  • N for no parity
  • 1 for a single stop bit

See page 125 of the Model 100 Owner's Manual for a description of all parameters, as well as page 165 for the open command.

A more in depth description and tutorial examples is provided in the Model 100 Basic Language Lab by Lesson #14 Using the COM Option starting at page 165.

  • 6
    Hi, My Model 100 required "COM:88N1E" ... now with the "E" it runs ... thanks!
    – wperko
    Sep 10, 2022 at 0:33

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .