[permalink] [id link]
DECtape II was introduced around 1978 and had a similar block structure, but used a much smaller 0. 150 " tape ( the same width as an audio compact cassette ).
from
Wikipedia
Some Related Sentences
DECtape and II
) The VT103 included a backplane socket for an LSI-11 minicomputer board and supported dual TU58 DECtape II block addressable tape drive which behaved like a very slow disk drive.
DECtape ( top and lower left ) and DECtape II ( lower right ) removable magnetic media
The TU58 DECtape II drive had an RS232 serial interface, allowing it to be used with the ordinary serial ports that were very common on Digital's contemporary processors.
Like its predecessor DECtape, and like the faster RX01 floppies used on the VAX-11 / 780, a DECtape II cartridge had a capacity of about 256 kilobytes.
However, rapid advances in low-cost floppy disk technology, which had an inherent speed advantage, soon outflanked the DECtape II and rendered it obsolete.
DECtape II drives were used for program and data storage.
DECtape and was
One of the most unusual peripherals produced for the PDP-10 was the DECtape.
The DECtape was a length of special 3 / 4-inch wide magnetic tape wound on 5-inch reels.
The DECtape was also widely used on other PDP models, since it was much easier to use than hand-loading multiple paper tapes.
The PDP-11 was booted from a dual-ported RP06 disk drive ( or alternatively from an 8 " floppy disk drive or DECtape ), and then commands could be given to the PDP-11 to start the main processor, which was typically booted from the same RP06 disk drive as the PDP-11.
The TX-2 Tape System was a block addressable 1 / 2 " tape developed for the TX-2 by Tom Stockebrand which evolved into LINCtape and DECtape.
The single-user BASIC used several overlays to provide the full functionality of the language ; when OS / 8 was booted from a DECtape, a very noticeable delay occurred each time BASIC was required to switch overlays as they needed to be read from tape.
It was a disk oriented system, faster than its predecessor the 4K Disk Monitor System, with tricks to make it run quickly on DECtape based systems.
DECtape, originally called " Microtape ", was a magnetic tape data storage medium used with many Digital Equipment Corporation computers, including the PDP-6, PDP-8, LINC-8, PDP-10, PDP-11, PDP-12, and the PDP-15.
DECtape had its origin in the LINCtape tape system, which was originally designed by Wesley Clark at the MIT Lincoln Laboratory as an integral part of the LINC computer.
DECtape used the same transport mechanism as LINCtape, but the tape was run in the opposite direction, thus the supply and takeup reels were reversed.
Mechanical dimensions, speeds, and signal characteristics were identical, and at least one system, the PDP-12 ( with the TC12-F option ), was capable of using either LINCtape or DECtape on the same transport.
DECtape was designed to be reliable and durable enough to be used as the main storage medium for a computer's operating system.
It was possible, though slow, to use a DECtape drive to run a small OS such as OS / 8 or OS / 12.
Upon its introduction, DECtape was considered a major improvement over hand-loaded paper tapes, which could not be used to support swap files essential for practical timesharing.
Early hard disk and drum drives were very expensive, limited in capacity, and notoriously unreliable, so the DECtape was a breakthrough in supporting the first timesharing systems on DEC computers.
The design of DECtape and its controllers was quite different from any other type of tape drive or controller.
The fundamental durability and reliability of DECtape was underscored when the design of the tape reel mounting hubs was changed in the early 1970s.
When a defective batch of these new design hubs was shipped on new DECtape drives, these hubs would loosen over time.
Experienced DECtape users learned to notice the characteristic " shoe-shining " motion of a failing DECtape as it was passed repeatedly back and forth over the tape heads, and would retire the tape from further use.
DECtape and had
EDU20 loaded from paper tape and could do output to a paper tape writer if the machine had one, whereas EDU25 understood the structure of a filesystem, could load from DECtape or disk, and could create files on DECtape or disk.
The data on the mangled DECtape could often be recovered completely and copied to another tape, provided that the original tape had only been creased multiple times, and not stretched or broken.
DECtape and used
DECtape used a significantly different mark track format to provide for the possibility of read and write operations in either direction.
Physically, DECtape used dual-redundancy to keep the error rate low.
DECtape and .
Files could be written, read, changed, and deleted on a DECtape as though it were a disk drive.
For greater efficiency, the DECtape drive could read and write to a DECtape in both directions.
In later years, DECtape drives were added to some PDP-1 systems, as a more convenient method of backing up programs and data, and to enable early timesharing.
PDP-11 / 40 with TU56 dual DECtape drive.
Some older tape drives-such as the DECtape, the ZX Microdrive and the Rotronics Wafadrive-were designed as inexpensive alternatives to disk drives which were at the time very expensive.
Upon startup, EDU25 would save the contents of memory to DECtape or disk and restore it when it exited.
PDP-11 with TU56 dual DECtape unit.
From a programming point of view, DECtape behaved like a very slow disk drive.
On the PDP-12, the DECtape drives were tightly integrated into the LINC CPU instruction set.
DECtape and tape
* TU56 — DECtape block-addressed tape system
DECtape and ).
Once designed into such products as the DECtape controller and the VT100 video terminal in the late 1970s, it served for new production throughout the life span of those products ( generally longer than the product life of desktop computers ).
The multi-user versions of BASIC ( EDU20 and EDU25 ) differed only in whether or not they supported block-replaceable devices ( DECtape or disk ).
0.145 seconds.