DECtape - определение. Что такое DECtape
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Что (кто) такое DECtape - определение

MAGNETIC TAPE DATA STORAGE MEDIA USED IN MANY DIGITAL EQUIPMENT CORPORATION COMPUTERS
LINCtape; TU55; TU56; DECtape-II; TU58; TC11; TC8E; TD8E; TC01; TC15; DECTape; DECtape II; DECTape II
  • COI LINC Tape II drive
  • A TU56 dual DECtape unit for a DEC PDP-11.  Note the 6-armed "starfish" hubs holding circular white tape reels in place. The vertical aluminium block above each pair of tape reels holds the read/write heads.
  • A partially restored LINC-8,<br> including LINCtape drives

DECtape         
<hardware, storage> A reel of magnetic tape about 4 inches in diameter and one inch wide. Unlike today's macrotapes, microtape drivers allowed random access to the data, and therefore could be used to support file systems and even for swapping (this was generally done purely for hack value, as they were far too slow for practical use). DECtape was a variant on LINCtape. In their heyday DECtapes were used in pretty much the same ways one would now use a floppy disk: as a small, portable way to save and transport files and programs. (1995-03-16)
DECtape         
DECtape, originally called Microtape, is a magnetic tape data storage medium used with many Digital Equipment Corporation computers, including the PDP-6, PDP-8, LINC-8, PDP-9, PDP-10, PDP-11, PDP-12, and the PDP-15. On DEC's 32-bit systems, VAX/VMS support for it was implemented but did not become an official part of the product lineup.
LINCtape         
<storage> A formatted, block-oriented, high-reliability, random access tape system used on the {Laboratory Instrument Computer}. The tape was 3/4" wide. The funny DECtape is actually a variant of the original LINCtape. According to Wesley Clark, DEC tried to "improve" the LINCtape system, which mechanically, was wonderfully simple and elegant. The DEC version had pressure fingers and tape guides to force alignment as well as huge DC servo motors and complex control circuitry. These literally shredded the tape to bits if not carefully adjusted, and required frequent cleaning to remove all the shedded tape oxide. That was amazing, because the tape had a micro-thin plastic layer OVER the oxide to protect it. What happened was that all the forced alignment stuff caused shredding at the edge. An independent company, Computer Operations[?], built LINCtape drives for use in nuclear submarines. This was based on the tape system's high reliability. Correspondent Brian Converse has a picture of himself holding a LINCtape punched full of 1/4" holes. It still worked! (1999-03-29)

Википедия

DECtape

DECtape, originally called Microtape, is a magnetic tape data storage medium used with many Digital Equipment Corporation computers, including the PDP-6, PDP-8, LINC-8, PDP-9, PDP-10, PDP-11, PDP-12, and the PDP-15. On DEC's 32-bit systems, VAX/VMS support for it was implemented but did not become an official part of the product lineup.

DECtapes are 3/4 inch (19 mm) wide, and formatted into blocks of data that can each be read or written individually. Each tape stores 184K 12-bit PDP-8 words or 144K 18-bit words. Block size is 128 12-bit words (for the 12-bit machines), or 256 18-bit words for the other machines (16, 18, 32, or 36 bit systems).

From a programming point of view,: p.505  because the system is block-oriented and allows random seeking, DECtape behaves like a very slow disk drive.