# Sequential Files
> [HTML Version](sequentialfiles.htm)
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Sequential file (aka stream) notes:
• Typically text-oriented, but may consist of raw binary data as well.
• Byte, field, or line-oriented.
• May contain variable length fields and lines, or simply be a stream of bytes.
• Open for input or output, but not both at the same time, except for the terminal.
• The terminal screen and keyboard are two special sequential files, implicitly opened for input and output, respectively, on channel #0.
• Record locking not supported.
• Serial ports may be accessed as sequential files.
• TCP sockets may be also be accessed as sequential files; see [MX\_FILESOCK](mx_filesock.htm.md).
• Output files grow automatically via PRINT.
• Access is by default sequential but 'cursor' can be repositioned using [MX\_FILEPOS](mx_filepos.htm.md)
**Subtopics**
- [OPEN](opensequential.htm.md)
- [INPUT](input_seq.htm.md)
- [PRINT](printstatement.htm.md)
- [WRITECD](writecd.htm.md)