Hp Tape Diagnostic Tools' title='Hp Tape Diagnostic Tools' />DECtape Wikipedia. A TU5. 6 dual DECtape unit for a DEC PDP 1. 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 readwrite heads. DECtape originally called Microtape is a magnetic tape data storage medium used with many Digital Equipment Corporationcomputers, including the PDP 6, PDP 8, LINC 8, PDP 9, PDP 1. PDP 1. 1, PDP 1. PDP 1. On DECs 3. VAXVMS support for it was implemented but did not become an official part of the product lineup. DECtapes1 are 34 inch 1. See pricing info, deals and product reviews for HP LaserJet Pro M402DN SingleFunction Mono Laser Printer at Quill. Order online today and get fast, free. Search titles only has image posted today bundle duplicates include nearby areas appletonoshkoshFDL app. Order Scotch Heavy Duty Shipping Tape. Fast and Free Shipping on all order at Quill. Get a great deal by ordering in bulk for your officeDownload basket downloads contacts product support community info warrantyservice. Search titles only has image posted today bundle duplicates include nearby areas akron canton cak altoonajohnstown aoo. Each tape stores 1. K 1. 2 bit PDP 8 words or 1. K 1. 8 bit words. Block size is 1. 28 1. From a programming point of view,1 p. DECtape behaves like a very slow disk drive. OriginseditDECtape has its origin in the LINCtape tape system,1 p. Hp Tape Diagnostic Tools' title='Hp Tape Diagnostic Tools' />Wesley Clark at the MIT Lincoln Laboratory as an integral part of the LINC computer. There are simple LINC instructions for reading and writing tape blocks using a single machine instruction. The design of the LINC, including LINCtape, was placed in the public domain because its development had been funded by the government. LINCtape drives were manufactured by several companies, including Digital. In turn, LINCtapes origin can be found in the magnetic tape system for the historic Lincoln Laboratory TX 2 computer, designed by Richard L. Best and T. C. Stockebrand. The TX 2 Tape System is the direct ancestor of LINCtape, including the use of two redundant sets of five tracks and a direct drive tape transport, but it uses a physically incompatible tape format inch Tape on 1. LINC tape and DECtape used inch tape on 4 inch reels. Digital initially introduced the Type 5. Microtape Control and Type 5. Dual Microtape Transport as peripherals for the PDP 1 and PDP 4 computers, both 1. Q1523B-4_grande.JPG?v=1482950259' alt='Hp Tape Diagnostic Tools' title='Hp Tape Diagnostic Tools' />DEC advertised the availability of these peripherals in March and May, 1. November, planning was already underway to offer the product for the 1. PDP 5 and 3. 6 bit PDP 6, even though this involved a change in recording format. The initial specifications for the Type 5. Search titles only has image posted today bundle duplicates include nearby areas baton rouge btr beaumont port arthur bpt. Dieselmanns Tech Page Diagnosis by Symptom. Open the Glossary for acronym explanations. Hard startlong crankcold only Nohard start hot or after stall, restarts. Search titles only has image posted today bundle duplicates include nearby areas billings, MT bil boise, ID boi. Replace the problem ink cartridge if you saw defects on the Print Quality Diagnostic report and the preceding steps did not resolve the issue, even if the ink. LINCtape, the ability to read and write in either direction. By late 1. 96. 4, the Type 5. DECtape transport. The tape transport used on the LINC is essentially the same as the Type 5. The LINC and DEC controllers, however, are incompatible, and the positions of the supply and take up reels were reversed between the LINC and DEC tape formats. While LINCtape supports high speed bidirectional block search, it only supports actual data read and write operations in the forward direction. Hp Tape Diagnostic Tools' title='Hp Tape Diagnostic Tools' />DECtape uses a significantly different mark track format to provide for the possibility of read and write operations in either direction, although not all DECtape controllers support reverse read. Fluke Usb Driver 199C. DEC applied for a patent on the enhanced features incorporated into DECtape in late 1. It is notable that the inventor listed on this patent, Thomas Stockebrand, is also an author of the paper on the TX 2 tape system from which the LINC tape was derived. Eventually, the TC1. RMVirtual/Media/Images/TEC1903309_ltt_hardwarescan.png' alt='Hp Tape Diagnostic Tools' title='Hp Tape Diagnostic Tools' />F tape controller on the PDP 1. LINCtape and DECtape on the same transport. As with the earlier LINC 8, the PDP 1. PDP 8 augmented with hardware support for the LINC instruction set and associated laboratory peripherals. Technical detailsedit. A partially restored LINC 8. LINCtape drives. DECtape was designed to be reliable and durable enough to be used as the main storage medium for a computers operating system OS. It is possible, although slow, to use a DECtape drive to run a small OS such as OS8 or OS1. The system would be configured to put temporary swap files on a second DECtape drive, so as to not slow down access to the main drive holding the system programs. 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 legendary PDP 1 at MIT, where early computer hacker culture developed, adopted multiple DECtape drives to support a primitive software sharing community. The hard disk system when it was working was considered a temporary file storage device used for speed, not to be trusted to hold files for long term storage. Computer users would keep their own personal work files on DECtapes, as well as software to be shared with others. The design of DECtape and its controllers is quite different from any other type of tape drive or controller at the time. The tape is 0. 7. Each track is paired with a non adjacent track for redundancy by wiring the tape heads in parallel as a result the electronics only deal with 5 tracks a clock track, a mark track and 3 data tracks. Manchester encoding PE was used. The clock and mark tracks are written only once, when the tape was formatted after that, they are read only. This meant a drop out on one channel could be tolerated even a hole punched through the tape with a 0. Another reason for DECtapes unusually high reliability is the use of laminated tape the magnetic oxide is sandwiched between two layers of mylar, rather than being on the surface as was common in other magnetic tape types. This allows the tape to survive many thousands of passes over the tape heads without wearing away the oxide layer, which would otherwise have occurred in heavy swap file use on timesharing systems. The fundamental durability and reliability of DECtape was underscored when the design of the tape reel mounting hubs was changed in the early 1. The original machined metal hub with a retaining spring was replaced by a lower cost single piece plastic hub with 6 flexible arms in a starfish or flower shape. When a defective batch of these new design hubs was shipped on new DECtape drives, these hubs would loosen over time. As a result, DECtape reels would fall off the drives, usually when being spun at full speed, as in an end to end seek. The reel of tape would fall onto the floor and roll in a straight line or circle, often unspooling and tangling the tape as it went. In spite of this horrifying spectacle, desperate users would carefully untangle that tape and wind it laboriously back onto the tape reel, then re install it onto the hub, with a paper shim to hold the reel more tightly. 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. DEC quickly issued an Engineering Change Order ECO to replace the defective hubs, to resolve the problem. Eventually, a heavily used or abused DECtape begins to become unreliable. The operating system is usually programmed to keep retrying a failed read operation, which often succeeds after multiple attempts. Experienced DECtape users learned to notice the characteristic shoe shining motion of a failing DECtape as it is passed repeatedly back and forth over the tape heads, and would retire the tape from further use. On non DEC computerseditComputer Operations Inc COI of Beltsville, Maryland offered a DECtape clone in the 1. Initially, COI offered LINC tape drives for computers made by Data General, Hewlett Packard and Varian, with only passing reference to its similarity to DECtape.