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 A tape drive is a data storage device that reads and writes data on a magnetic tape. Magnetic tape data storage is typically used for offline, archival data storage. Tape media generally has a favorable unit cost and a long archival stability. ...

developed by Exatron.

History

The company introduced an S-100 stringy floppy drive at the 1978

West Coast Computer Faire The West Coast Computer Faire was an annual computer industry conference and exposition most often associated with San Francisco, its first and most frequent venue. The first fair was held in 1977 and was organized by Jim Warren and Bob Reil ...

, and a version for the

Radio Shack RadioShack, formerly RadioShack Corporation, is an American retailer founded in 1921. At its peak in 1999, RadioShack operated over 8,000 worldwide stores named RadioShack or Tandy Electronics in the United States, Mexico, United Kingdom, Austra ...

TRS-80 The TRS-80 Micro Computer System (TRS-80, later renamed the Model I to distinguish it from successors) is a desktop microcomputer launched in 1977 and sold by Tandy Corporation through their Radio Shack stores. The name is an abbreviation of '' ...

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 thick. The magnetic tape inside the cartridge is 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 Random access (more precisely and more generally called direct access) is the ability to access an arbitrary element of a sequence in equal time or any datum from a population of addressable elements roughly as easily and efficiently as any othe ...

data files (unlike a

datacassette Magnetic-tape data storage is a system for storing digital information on magnetic tape using digital recording. Tape was an important medium for primary data storage in early computers, typically using large open reels of 7-track, later 9-t ...

). 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. According to ''Embedded Systems'' magazine, the Exatron Stringy Floppy uses

Manchester encoding In telecommunication and data storage, Manchester code (also known as phase encoding, or PE) is a line code in which the encoding of each data bit is either low then high, or high then low, for equal time. It is a self-clocking signal with no D ...

, achieving 14K read-write speeds and the code controlling the device was developed by

Li-Chen Wang Li-Chen Wang (born 1935) is an American computer engineer, best known for his ''Palo Alto Tiny BASIC'' for Intel 8080-based microcomputers. He was a member of the Homebrew Computer Club and made significant contributions to the software for early ...

, who also wrote a

Tiny BASIC Tiny BASIC is a family of dialects of the BASIC programming language that can fit into 4 or fewer KBs of memory. Tiny BASIC was designed in response to the open letter published by Bill Gates complaining about users pirating Altair BASIC, which ...

, the basis for the TRS-80 Model I Level I BASIC.

Reception

In the July 1983 issue of ''

Compute!'s Gazette ''Compute!'s Gazette'' (), stylized as ''COMPUTE!'s Gazette'', was a computer magazine of the 1980s, directed at users of Commodore's 8-bit home computers. Announced as ''The Commodore Gazette'', it was a Commodore-only daughter magazine of the ...

'', the Exatron Stringy Floppy for the

VIC-20 The VIC-20 (known as the VC-20 in Germany and the VIC-1001 in Japan) is an 8-bit home computer that was sold by Commodore Business Machines. The VIC-20 was announced in 1980, roughly three years after Commodore's first personal computer, the PE ...

and the

Commodore 64 The Commodore 64, also known as the C64, is an 8-bit home computer introduced in January 1982 by Commodore International (first shown at the Consumer Electronics Show, January 7–10, 1982, in Las Vegas). It has been listed in the Guinness ...

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 VIC-1540/ 1541 disk drive".

Texas Instruments Texas Instruments Incorporated (TI) is an American technology company headquartered in Dallas, Texas, that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globall ...

licensed the Stringy Floppy as the Waferdrive for its cancelled TI 99/2 computer and a

Compact Computer 40 The Compact Computer 40 or CC-40 is a portable computer developed by Texas Instruments. It started development in 1981, and was released in March 1983 for US$249. The CC-40 has a single-line 31 character LCD display, weighs 600 grams (22 ounc ...

peripheral which never shipped.

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. Cartridges, or "wafers", were available in tape lengths ranging from . Known data capacities/tape length are: 4 kB/5 feet, 16 kB/20 feet, 48 kB/50 feet, and 64 kB/75 feet. One complete cycle through a tape takes 55 to 65 seconds, depending on the number of files it contains.

References

External links