Sequential files are:

•   text-oriented, typically

•   byte, field, or line-oriented

•   variable length fields and lines

•   files are opened for input or output, but not both

•   no record locking

•   the screen is a special sequential file; open for output on channel 0

•   the keyboard is a special sequential file; open for input

•   serial ports may be accessed as sequential files

•   output files may be created by the OPEN statement and grow automatically via PRINT

•   the DATA statement pool acts like a sequential input file, internal to the program

•   access is by default sequential but can be overridden using MX_FILEPOS.