Editing Kermit (protocol) (section)

==Technical==
The Kermit protocol supports [[Text file|text]] and [[binary file]] transfers on both full-duplex and half-duplex 8-bit and 7-bit [[RS-232|serial]] connections in a system- and medium-independent fashion, and is implemented on hundreds of different computer and operating system platforms. On full-duplex connections, a [[sliding window protocol]] is used with selective retransmission which provides excellent performance and error recovery characteristics. On 7-bit connections, locking shifts provide efficient transfer of 8-bit data. When properly implemented, as in the [[Columbia University]] Kermit Software collection, its authors claim performance is equal to or better than other protocols such as [[ZMODEM]], [[YMODEM]], and [[XMODEM]], especially on poor connections.<ref>Some of the sentences in the Technical section are based on text copied, on 30 October 2004, from the [[Free On-line Dictionary of Computing]], which is licensed under the [[GFDL]].</ref> On connections over [[RS-232]] [[Statistical time-division multiplexing|Statistical Multiplexers]] where some [[ASCII#ASCII control characters|control characters]] cannot be transmitted,{{Citation needed|date=August 2011}} Kermit can be configured to work, unlike protocols like XMODEM that require the connection to be transparent (i.e. all 256 possible values of a byte to be transferable).

Kermit can be used as a means to [[Bootstrapping|bootstrap]] other software, even itself. To distribute Kermit through non [[8-bit clean]] networks Columbia developed '''.boo''', a [[binary-to-text encoding]] system similar to [[BinHex]]. For instance, [[IBM PC compatible]]s and [[Apple computer]]s with a [[Compatibility card|Compatibility Card]] installed can connect to otherwise incompatible systems such as a [[mainframe computer]] to receive [[MS-DOS]] Kermit in .boo format. Users can then [[type-in program|type in a "baby Kermit"]] in [[BASIC]] on their personal computers that downloads Kermit and converts it into binary.<ref name="dacruz19860320">{{cite mailing list | url=http://www.columbia.edu/kermit/ftp/e/mail.86a | title=Re: Printable Encodings for Binary Files | publisher=Kermit Project, Columbia University | mailing-list=Info-Kermit Digest | date=1986-03-20 | access-date=1 March 2016 | author=da Cruz, Frank}}</ref><ref name="fuller19891011">{{cite mailing list | url=http://www.columbia.edu/kermit/ftp/e/mail.89b | title=Kermit Bootstrapping | publisher=Kermit Project, Columbia University | mailing-list=Info-Kermit Digest | date=1989-10-11 | access-date=5 March 2016 |author1=Fuller, Bill |author2=da Cruz, Frank }}</ref>

Similarly, [[CP/M]] machines use many different [[floppy disk]] formats, which means that one machine often cannot read disks from another CP/M machine, and Kermit is used as part of a process to transfer applications and data between CP/M machines and other machines with different operating systems. The CP/M file-copy program [[Peripheral Interchange Program|PIP]] can usually access a computer's serial ([[RS-232]]) port, and if configured to use a very low [[baud]] rate (because it has no built-in error correction) can be used to transfer a small, simple version of Kermit from one machine to another over a [[null modem]] cable, or failing that, a very simple version of the Kermit protocol can be hand coded in binary in less than 2K using DDT, the CP/M Dynamic Debugging Tool. Once done, the simple version of Kermit can be used to download a fully functional version. That version can then be used to transfer any CP/M application or data.<ref>{{Cite web|first=C. |last=Gianone |title=CP/M-80 KERMIT VERSION 4.11 USER GUIDE|publisher=Columbia University Center for Computing Activities|location=New York|date=23 April 1991|url=http://www.z80.eu/downloads/cpkermit.txt}} See "Figure 1-1:  Bootstrap program for Kermit-80 and CP/M Version 2.2"</ref>

Newer versions of Kermit included [[scripting language]] and automation of commands.<ref>[http://www.columbia.edu/kermit/k95.html columbia.edu Kermit 95]</ref> The Kermit scripting language evolved from its [[TOPS-20]] EXEC-inspired command language<ref>{{cite web |title=C-Kermit / Kermit 95 Scripting Tutorial and Library|url=http://www.kermitproject.org/ckscripts.html#introduction}}</ref> and was influenced syntactically and semantically by [[ALGOL 60]], [[C (programming language)|C]], [[BLISS|BLISS-10]], [[PL/I]], [[SNOBOL]], and [[Lisp (programming language)|LISP]].<ref>{{cite web |title=C-Kermit / Kermit 95 Scripting Tutorial and Library |url=https://kermitproject.org/ckscripts.html#intro }}</ref>

The correctness of the Kermit protocol has been verified with formal methods.<ref>{{Cite book|title=Specification and validation methods|last=Huggins|first=James K.|publisher=Oxford University Press|year=1995|isbn=0-19-853854-5|editor-last=Börger|editor-first=Egon|location=New York|pages=247–293|chapter=Kermit: specification and verification|chapter-url=http://www.kermitproject.org/proof.pdf}}</ref>