DOS Text File Transfer

Set com port mode on PC; e.g.:

MODE COM1:96,N,8,1

Open TEXT

Enter File Name (.DO will be appended)

F2 (Load from:) COM:88N1E (match PC setting)

Send file from PC; e.g.:

COPY <filename> COM1

Note that nothing displays (which is why it can run faster).

Wait to make sure it's all sent.

Shift Pause/break.

No need to worry about file extensions but of course the file has to be ASCII text, which includes text (.DO) versions of BASIC programs.