Datassette
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The Commodore 1530* (C2N) Datassette (a portmanteau of data + cassette), was Commodore's dedicated computer tape recorder. It provided access to an inexpensive storage medium for Commodore's 8-bit home/personal computers, notably the PET, VIC-20, and C64.
(* See the Main models section for information on the Commodore 1531. )
Confusingly, the Datassette at various times was sold both as the C2N DATASETTE UNIT Model 1530 and as the 1530 DATASSETTE UNIT Model C2N. Note the difference in spelling (one versus two s 'es) used on the original product packaging.
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[edit] Description and history
The Datassette contained built-in A/D converters and audio filters to convert the computer's digital information into analog sound and vice versa (much like a modem does over a telephone line). Connection to the computer was done via a proprietary mini-DIN plug or edge connector. The absence of recordable audio signals on this interface made the Datassette and its few clones the only cassette recorders usable with CBM's machines, until aftermarket converters made the use of ordinary recorders possible.
The inexpensive and widely available audio cassettes made the Datassette a good choice for the budget-aware home computer mass market. In Europe, the Datassette was the medium of choice for several years after its launch, although floppy disk drives were generally available. In the U.S., however, disk drives quickly became standard, despite the Commodore 1541 floppy drive costing roughly 5 times as much as a Datassette.
The Datassette was a very slow and fairly unreliable medium (the latter caused by the sensitivity of the encoded analog signal to disturbances by magnetic fields and tape failure). Contemporary disk drives were an order of magnitude faster and more reliable. Some years after the Datassette's launch, however, special turbo tape compression software appeared, providing much faster tape operation (loading and saving). Such software was available for loading commercial prerecorded applications (mostly games), as well as for loading and saving the users' homemade programs and data.
Datasettes could typically store about 200 KB (100+ KB per 30 minute side, [1]).
[edit] Main models
[edit] Used with the PET, VIC-20, C64/128
The are at least four main models of the 1530/C2N Datassette, listed chronologically below. The first two external models were made as PET peripherals, and styled after the PET 2001 built-in tape drive. The latter two were styled and marketed for the VIC-20 and C64. All 1530s were compatible with all those computers, as well as the C128.
- The built-in Datassette in the original PET 2001: black cassette lid, five white keys, no tape counter, no SAVE LED
- Black body original shape model, black cassette lid, five black keys, no tape counter, no SAVE LED
- White body original shape model, black cassette lid, five black keys, with tape counter, no SAVE LED
- White body new shape model, silver cassette lid, six black keys, with tape counter and a red SAVE LED
In addition to this, some models came with a small hole above the keys, to allow access to the adjustment screw of the tape head azimuth position. A small screwdriver could thus easily be used to effect the adjustment without disassembling the Datassette's chassis.
[edit] Used with the C16/116 and Plus/4
Similar in physical appearance but incompatible both in connector and storage format with the 1530/C2N models is the Commodore 1531, made for the Commodore 16 and Plus/4 series computers.
- Black/Charcoal body new shape model, silver cassette lid, six light gray keys, with tape counter and a red SAVE LED
Through the use of an adaptor, it could be used with a C64/128.
[edit] External links
| Magnetic tape data storage formats | ||
|---|---|---|
| Linear | Helical-Scan | |
| Three Quarter Inch (~19 mm) |
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| Half Inch (12.65 mm) |
UNISERVO (1951) - IBM 7 Track (1952) - IBM 9 Track (1964) - IBM 3480 (1984) - DLT (1984) - IBM 3590 (1995) - T9840 (1998) - T9940 (2000) - LTO Ultrium (2000) - T10000 (2006) |
Redwood SD-3 (1995) - DTF (19xx) - SAIT (2003) |
| Eight Millimeter (8 mm) |
Travan (1995) - IBM 3570 MP (1997) |
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| Quarter Inch (6.35 mm) |
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| Four Millimeter (3.8 mm) |
DDS/DAT (1989) |
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| One Eighth Inch (3.18 mm) |
KC Standard, Compact Cassette (1975) - Datassette (1977) |
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| Stringy (1.58 - 1.9 mm) |
Exatron Stringy Floppy (1979) - ZX Microdrive (1983) - Rotronics Wafadrive (1984) |
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