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| | Drum memory - Wikipedia, the free encyclopedia |
 | | Drum memory was an early form of computer memory that was widely used in the 1950s and into the 1960s. | | | Librascope LGP-30 – The drum memory computer referenced in the above story, also referenced on Librascope LGP-30. | | | They did this by carefully timing how long it would take for a particular instruction to run and the computer to ready itself to read the next instruction, then placing that instruction on the drum so that it was just arriving under the heads at that point in time. |
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http://en.wikipedia.org/wiki/Drum_memory
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| | drum on Encyclopedia.com |
| | Magnetic Drum Memory This magnetic drum unit was the memory in the IBM 650 computer, introduced in 1954. | | | A Magnetic Drum This magnetic drum added additional storage to the Whirlwind computer in the early 1950s. |
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http://www.encyclopedia.com/html/d1/drum-mus.asp
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| | Random access memory - Wikipedia, the free encyclopedia |
| | This is in contrast to sequential memory devices such as magnetic tapes, discs and drums, in which the mechanical movement of the storage medium forces the computer to access data in a fixed order. | | | In today's computers memory access is becoming very slow when compared to CPU cycles since most computers use cheap, but comparatively slow, DRAM for the main memory. | | | Core memory, which used wires attached to small ferrite electromagnetic cores, also had roughly equal access time (the term “core” is still used by some programmers to describe the RAM at the heart of a computer). |
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http://en.wikipedia.org/wiki/Random_access_memory
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| | Drum memory - LinuxQuestions.org Wiki |
| | Drum memory was a form of computer memory used during the Bronze Age of computing. | | | Drum memory was, to a certain extent, sequential, rather than random, like today's modern RAM, in that you had to wait for the section with your data to pass under the read/write head. | | | In the Story of Mel, Mel used this property to avoid writting delay loops, by placing needed data in the most "pessimum" site on the drum, meaning that the computer had to wait for the data to be read. |
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http://wiki.linuxquestions.org/wiki/Drum_memory
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| | Unisys History Newsletter v3n3 |
| | ERA was more familiar with drum memory technology, and in fact had done design studies for IBM and NBS in 1949-1950 for drum memory computers, neither of which was built. | | | The drum was, of course, constantly rotating while the processor was executing each instruction, so that there was no guarantee that the read-write head would be positioned at the next instruction when execution of the previous one was completed. | | | The first tasks involved the development of various components, such as drum memories, which could be used to facilitate cryptologic work. |
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http://www.cc.gatech.edu/gvu/people/randy.carpenter/folklore/v3n3.html
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| | Intro to System Software, Chapter 11 |
| | Drums were introduced in 1952 on the Whirlwind I computer; by 1961, the Manchester University Atlas computer was using a primitive file system which blurred the distinction between drum and tape. | | | The oldest random-access secondary storage device is the magnetic drum memory, although it is worth noting that some early computers actually used drum technology for their primary memory. | | | For example, in the 1970's, when core memory was still common as the primary memory of large computers, typically with sizes under one megabyte, bulk core memory was used as secondary memory in sizes up to about 16 megabytes. |
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http://www.cs.uiowa.edu/~jones/syssoft/notes/11disk.html
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| | Mos shift register compensation system for defective tracks of drum storage system - Patent 4016547 |
| | Therefore, there is a continuing need in the state of the art for an electronics package which compensates for the loss of a track in a rotating magnetic drum memory and which stores and recirculates the data until it is read out by interconnected logic circuitry. | | | One well known and widely used means of storing digital data is to record the data on a rotating magnetic drum memory. | | | Yet another object of the invention is to provide for a solid state data storage compensator which is compatible with a magnetic rotating drum memory. |
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http://www.freepatentsonline.com/4016547.html
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| | IBM Archives: 650 RAMAC fact sheet 1959 |
| | With the IBM 355 magnetic disk memory unit, the RAMAC 650 system is able to go directly to a specific piece of information without searching for it through all the other stored data. | | | Random access memory is expanded with the use of double capacity memory disks. | | | The average access time to data or instructions on the magnetic drum memory is 2.4 milliseconds -- 2.4 thousandths of a second. |
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http://www-1.ibm.com/ibm/history/exhibits/650/650_tr2.html
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| | WPS:LGP 21:Software |
| | The usefulness of a drum type computer depends on this correspondence between magnetized spots and binary digits. | | | The LGP-30 has as large a memory, requires as few operators, is as fast, and is as easy-to program as any other, general purpose stored program computer now in its price range. | | | The heart of the memory section of the Royal Precision electronic computer LGP-30 is the magnetic drum shown below. |
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http://www.wps.com/projects/LGP-21/Software/lgp-30-man.html
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| | Mainframe |
| | First use of virtual memory in a mainframe computer. | | | On line memory was a crucial phase in developing large computers. | | | It was a large-scale, electronic digital computer used for solving complex scientific, engineering and business problems and was the first IBM machine to use FORTRAN. |
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http://www.thocp.net/hardware/mainframe.htm
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| | Doug's Forum - Vacuum Tube Computer and Drum Memory |
| | This isn't the exact computer but will give you an idea of what the old 1950's era computers were like. | | | The air conditioner was nearly as big as the computer room. | | | And here is a picture of a Drum Memory storage unit. |
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http://www.dougscode.com/forum4/topic.asp?TOPIC_ID=15
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| | [No title] |
| | Patch memory is not cleared when the device is closed, however, so a subsequent call to cache patches with _exactly_ the same PATCHARRAY does not cause the driver to clear memory and reload the patches. | | | Drum memory starts at the end of melodic memory. | | | The second problem is caused by the current implementation of the Ultrasound "firmware". |
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http://ftp.gravis.com/Public/sdk/GTEK19.TXT
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| | [No title] |
| | The disadvantage of drums, of course, was that you got a lot less storage per spindle than you did with a disk, but drums were popular well into the 1960s for swapping and loading frequently used programs because they were so fast. | | | Coat a drum with iron oxide rather than carborundum and poof, it's a computer memory. | | | Drums had a fixed head per track, so they avoided the problems of moving heads and floating heads that made early disk development difficult. |
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http://www.memex.org/cm-archive9.html
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| | IBM 650 |
| | The 650 is a two-address, bi-quinary coded decimal machine (both data and addresses were decimal), with memory on a rotating drum. | | | The 650 was specifically designed for users of existing IBM unit record equipment (electro-mechanical punched card-processing machines) upgrading from so-called Calculating Punches, like the IBM 604 model, to computers proper. | | | Programs could be optimized by placing instructions around the drum based on the expected execution time of the previous instruction. |
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http://www.worldhistory.com/wiki/I/IBM-650.htm
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| | Apollo Guidance Computer and Other Computer History |
| | For example, assigned memory addresses in the scratch-pad memory are used in place of the several arithmetic registers such as A, Q, and X, and counters, such as velocity and incremental accumulators required by conventional computers. | | | The inherent flexibility of the instruction logic provides an effective saving in program memory capacity of more than fifty per cent over single address drum computers, and a smaller but significant saving over indirectly addressed computers, that is, computers without extensions or switching. | | | Although it is a serial machine, computation rates are enhanced by access to memory in parallel while multiplication, division and square root processes in quasi-parallel, using unusual algorithms for minimization of hardware. |
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http://klabs.org/richcontent/Misc_Content/AGC_And_History/AGC_History.htm
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| | The IBM 650 |
| | In computers with solid state memory, instructions are naturally stored and executed in sequence -- after each non-Branch instruction the program counter is automatically incremented to the address of the next one. | | | Support for the 650 was withdrawn by IBM in 1969. | | | Thus 650 programming was not just a matter of algorithm and numerical analysis, but also of optimizing the arrangement of instructions to prevent drum latency from slowing the program down. |
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http://www.columbia.edu/acis/history/650.html
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| | Early Computers |
| | If you program a drum machine with the instructions stored sequentially, you have to wait at least one drum revolution to read the next instruction. | | | The above is based on memory, supplemented by a brochure I have on the LGP-21, a transistorized version of the LGP-30 that General Precision tried to market. | | | By carefully calculating the expected execution time for each instruction, you could place the next instruction at the right angle around the drum so that it would be coming up under a read head when the current instruction was done. |
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http://world.std.com/~reinhold/dir/computer-history.html
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| | OS Project Description 2 |
| | Drmint: invoked when the drum DMA unit generates an interrupt (a program transfer between the drum and memory has completed a swap). | | | In order to swap a job into memory from the drum (say, job ComingIn), OS must invoke the memory manager to allocate a block of free memory for the job. | | | -if there is room in memory to swap in another job;if there is, swap in a job. |
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http://www.sci.brooklyn.cuny.edu/~jones/CIS25/osproj2.html
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| | IBM@70 - Celebrating 70 years in Australia [Key milestone] 1953 |
| | With a magnetic drum memory, AGL's IBM 650 was used in conjunction with auxiliary machines such as sorters, collators and accounting machines, all of which were based upon punched card technology. | | | By October 1959, AGL had programmed the new computer to bill its 335,000 customers. | | | First released in 1953 with magnetic drum memory and priced at less than half a million dollars, the 650 was relatively cheap. |
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http://www-8.ibm.com/au/70years/more_detail/1953.html
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| | THE |
| | Above level 2, every process thinks it has its own private console, its own CPU, and doesn't care about physical memory since it deals with segments. | | | EL X8 machine, 32K 2.3 uS core memory, 512K, 40ms drum disk | | | Observation that it doesn't matter if programs' code pages are contiguous on drum, or even which drum page is used to back a core page. |
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http://www-db.stanford.edu/~manku/quals/summaries/gribble-the.htm
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| | Computer museum at Computer Museum of America - CalAdventures.com - Download Coupon here. digital computer, burroughs ... |
| | Visit us for Computer museum, California museum tour, San Diego museum, Computer history, digital computer, burroughs computer, drum memory disk, Digital Development Corporation, Computer Museum of America. | | | digital computer, burroughs computer, drum memory disk, Digital Development Corporation, Computer Museum of America | | | They used a MOS Technology 6502 microprocessor and had 4K of memory. |
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http://www.caladventures.com/ComputerMuseum.htm
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| | What is /dev/drum? [rec.humor.funny] |
| | Long, long ago, even before version 6, somebody wanted to implement a program to copy files between two machines running Unix. | | | He added a drum interface to his PDP-11 and the device driver was called, of course, /dev/drum. | | | Uucp would call a lower level program called `bang' to activate this device driver. |
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http://www.netfunny.com/rhf/jokes/91q1/devdrum.html
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| | US PATENT SUBCLASS 711 / 4-- .~ Dynamic-type storage device (e.g., disk, tape, drum) |
| | .~ Dynamic-type storage device (e.g., disk, tape, drum) | | | US PATENT SUBCLASS 711 / 4--.~ Dynamic-type storage device (e.g., disk, tape, drum) | | | (under subclass 1) Subject matter wherein address schemes are particular to a data storage device requiring relative motion between a data holding medium and a recording mechanism such as disk, tape, or drum memory. |
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http://www.patentec.com/data/class/defs/711/4.html
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| | Computer Museum of America |
| | The Digital Development Corporation Mass Storage Module Drive was used in the Control Data Corporation CDC-636 computer and represents an alternative memory technology that was crushed by the emergence of core memory technology. | | | The drum rotates a 3,600 RPM, with a data transfer rate of 60 CPS. | | | Once the unit reached its operational temperature, it had to cool down for three hours before the cover could be opened for servicing. |
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http://www.computer-museum.org/main/collections/drmemdsk.shtml
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| | hard drive - encyclopedia article about hard drive. |
| | The first notable casualty of the business in the PC era was Computer Memories International or CMI; after the 1985 incident with the faulty 20MB AT drives, CMI's reputation never recovered, and they exited the hard drive business in 1987. | | | Dozens of former hard drive manufacturers have gone out of business, merged, or closed their hard drive divisions; as capacities and demand for products increased, profits became hard to find, and there were shakeouts in the late 1980s and late 1990s. | | | Another notable failure was MiniScribe, who went bankrupt in 1990 after it was found that they had "cooked the books" and inflated sales numbers for several years. |
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http://encyclopedia.thefreedictionary.com/hard%20drive
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| | Dans Music Shop - Yamaha DSXT10 Drum Kit |
| | Wave data which can also be written from the cards to internal memory (this operation can also be done automatically). | | | Although the DTXTREME is a dedicated electronic percussion system, it's 64 polyphonic AWM@(advance Wave Memory) GM compatible tone generator allows playback of MIDI song data and access to YAMAHA'S XG format. | | | The DTXTREME incorporates a newly developed sound chip and expanded drum sound wave memory that has a capacity 3.5 times greater than the original DTX system. |
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http://www.dansmusic.flyer.co.uk/DTXTREMEWEBPAGE.htm
(649 words)
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| | TabX.net - Metallica / The Memory Remains Drum Tab File |
| | Your browser does not support inline frames or is currently configured not to display inline frames. | | | Metallica - The Memory Remains Drum Tab File | | | TabX.net - Metallica / The Memory Remains Drum Tab File |
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http://www.tabx.net/id-4099_file.html
(85 words)
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| | [No title] |
| | To perform (a piece or tune) on or as if on a drum. | | | To produce a booming, reverberating sound by beating the wings, as certain birds do. | | | A percussion instrument consisting of a hollow cylinder or hemisphere with a membrane stretched tightly over one or both ends, played by beating with the hands or sticks. |
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http://www.homoexcelsior.com/omega.db/datum/computer_science/drum
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| | Welcome to Drum Corps World |
| | All active and former members of the USMC and USAF, as well as past and present members of any drum & bugle corps, are invited to attend this fitting memorial for "one of their own." | | | These veterans will, in turn, present the flags to the color guard of the Chicago Royal Airs, who will carry them proudly as a permanent memorial to their former musical director/arranger and beloved friend and mentor. | | | The local ceremony will be held March 15, at 9:30 AM at Bednarcik Junior High School in Oswego, IL. |
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http://www.drumcorpsworld.com/articles.cfm?ID=237
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| | Sam Ash - 1-800-4-SAMASH |
| | Tama Limited Edition 7-Piece Starclassic Exotic Drum Set in Mediterranean Sea Blue |
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http://www.SamAsh.com
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