Editing Exatron Stringy Floppy

{{short description|Magnetic tape storage format}}
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[[file:Esf model 1.jpg|thumb|An Exatron Stringy Floppy (cover removed) designed for use with the TRS-80 Model 1]]

The '''Exatron Stringy Floppy''' (or '''ESF''') is a continuous-loop [[tape drive]] developed by [[Exatron]].

== History ==

The company introduced an [[S-100 bus|S-100]] stringy floppy drive at the 1978 [[West Coast Computer Faire]], and a version for the [[RadioShack|Radio Shack]] [[TRS-80]] in 1979. Exatron sold about 4,000 TRS-80 drives by August 1981 for $249.50 each, stating that it was "our best seller by far". The tape cartridge is about the size of a business card, but about {{convert|3/16|in|mm|1}} thick.<ref name="barry19810831">{{cite news | url=https://books.google.com/books?id=rD0EAAAAMBAJ&pg=PA47 | title=Stringy Floppy from Exatron | work=[[InfoWorld]] | date=1981-08-31 | accessdate=15 February 2015 | author=Barry, John | pages=47–48}}</ref> The magnetic tape inside the cartridge is {{convert|1/16|in|mm|1}} wide.

== Format ==

There is no single catalog of files; to load a specific file the drive searches the entire tape, briefly stopping to read the header of each found file. The tape loop only moves in one direction, so a file that starts behind the current location cannot be read until the drive searches the entire loop for it. The device is capable of reading and writing [[random access]] data files (unlike a [[datacassette]]). If a record being sought has been overshot, the drive advances the tape until it loops around to the beginning and continues seeking from there.{{r|halfhill198307}}

According to ''Embedded Systems'' magazine, the Exatron Stringy Floppy uses [[Manchester code|Manchester encoding]], achieving 14K read-write speeds and the code controlling the device was developed by [[Li-Chen Wang]], who also wrote a [[Tiny BASIC]], the basis for the [[Level I BASIC|TRS-80 Model I Level I BASIC]].

== Reception ==
In the July 1983 issue of ''[[Compute!'s Gazette]]'', the Exatron Stringy Floppy for the [[VIC-20]] and the [[Commodore 64]] was reviewed. Calling the peripheral "a viable alternative" to tape or disk, the magazine noted that "under ideal conditions, a Stringy Floppy can outperform a [[Commodore 1540|VIC-1540]]/[[Commodore 1541|1541]] disk drive". [[Texas Instruments]] licensed the Stringy Floppy as the Waferdrive for its cancelled [[TI-99/4A|TI 99/2]] computer and a [[Compact Computer 40]] peripheral which never shipped.<ref name="mace19830530saddle">{{Cite magazine |last=Mace |first=Scott |date=1983-05-30 |title=Texas Instruments in the Saddle |url=https://books.google.com/books?id=4S8EAAAAMBAJ&lpg=PA29&pg=PA26#v=onepage&q&f=false |access-date=2024-12-29 |magazine=InfoWorld |pages=26-28}}</ref><ref name="halfhill198307">{{cite news | url=https://archive.org/stream/1983-07-computegazette/Compute_Gazette_Issue_01_1983_Jul#page/n59/mode/2up | title=Exatron Stringy Floppy for VIC-20 and 64 | work=Compute!'s Gazette | date=July 1983 | accessdate=6 February 2016 | author=Halfhill, Tom R. | pages=58–62}}</ref>

== Use and distribution ==

The Exatron drive was initially used in the [[Prophet-10]] music synthesizer and was later replaced with a micro-cassette drive from Braemar, reportedly due to unreliability and poor mutual compatibility of the former.<ref name="Reid 1999">{{cite web|url=http://www.soundonsound.com/sos/mar99/articles/retroprophet.htm|title=Sequential Circuits&nbsp;– Prophet Synthesizers 5 & 10 (Retro)|last=Reid|first=Gordon|date=March 1999|work=[[Sound on Sound]]|archive-url=https://web.archive.org/web/20160203065241/http://www.soundonsound.com/sos/mar99/articles/retroprophet.htm|archive-date=3 February 2016|accessdate=January 23, 2015}}</ref>

Cartridges, or "wafers", were available in tape lengths ranging from {{Convert|5 to 75|ft|m}}.{{r|barry19810831}} Known data capacities/tape length are: 4&nbsp;kB/5 feet, 16&nbsp;kB/20 feet, 48&nbsp;kB/50 feet, and 64&nbsp;kB/75 feet.<ref>{{cite web|title=The Exatron Stringy Floppy|first=Matthew |last=Reed |url=http://www.trs-80.org/exatron-stringy-floppy/|accessdate=23 March 2014}}</ref> One complete cycle through a {{Convert|20|ft|m|adj=on}} tape takes 55 to 65 seconds, depending on the number of files it contains.{{r|halfhill198307}}

== See also ==

* [[ZX Microdrive]]
* [[Rotronics Wafadrive]]

== References ==

{{refs}}

== External links ==

* [http://www.digibarn.com/collections/devices/stringy-floppy/ Exatron Stringy Floppy as described by Bill Fletcher]
* [http://www.classic-computers.org.nz/system-80/software_esf_archive-imaging.htm Getting Files off Stringy Floppy Wafers for use in Emulators]
* [http://www.trs-80.org/exatron-stringy-floppy/ Advertisements]
* [http://www.exatron.com/ Exatron Official Website]

{{Magnetic tape data formats}}

[[Category:Computer storage devices]]
[[Category:Home computer peripherals]]
[[Category:TRS-80]]
[[Category:Computer-related introductions in 1979]]