Information Storage and Spintronics 05 Atsufumi Hirohata Department of Electronic Engineering 15:00 Monday, 15/October/2018 (J/P 004)

Quick Review over the Last Lecture LTO Storage : 12.65 mm wide tape / 1280 tracks Track width : 8.1 mm Length : 800 m < 5 mm left / right distributions < 10 nm surface roughness Top ferromagnetic layer Bottom non-magnetic layer Smooth base film (PET, PEN or PA) 70 ~ 80 % thickness Back coating Servo-signal Servo-band 320 320 1280 320 320 Track width : 8.1 mm * http://home.jeita.or.jp/

05 Development of Magnetic Storages Drum memory Core memory Bubble memory Floppy disk Storage hierarchy

Punched Tape Punched tapes were originally used for teletypes : * 0.1-mm thick tapes were used. American Standard Code for Information Interexchnage (ASCII) standardised the format in 1963. 1-inch wide tape 0.072-inch diameter holes with 0.1-inch separation 7-level code including feed holes Long lifetime Easy to repair No magnetic damages Easy to dispose Low fidelity Easy to damage Low recording density Limited usage * http://www.wikipedia.org

Punched Card Punched cards were originally used for loom patterns : * In 1832, Semen Korsakov used for informatics. Charles Babbage proposed a calculating machine, “Number Cards.” Herman Hollerith invented a tabulating machine in 1890. ® Tabulating Machine Company (1896) ® IBM 80-column card in dollar note size ® 80-characters column programming Long lifetime Easy to sort No magnetic damages Easy to dispose Difficult to miniaturise Remaining punched out bits Low recording density * http://www.wikipedia.org

Magnetic Drum Memory In 1932, Gustav Tauschek invented a magnetic drum memory : * Widely used in 1950s and 60s. Ferromagnetic materials are coated on a drum. ** Read / write heads are placed in one line with defining tracks. Slow access Mechanical failure ® Magnetic core memory Small capacity ® Hard disk drive * http://austria-forum.org/af/Wissenssammlungen/Erfinder/Tauschek,%20Gustav; *** http://www.computermuseum.li/Testpage/DRUM-Memory-BendixG15computer.htm ** http://www.wikipedia.org/;

Magnetic Core Memory In 1949, An Wang and Way-Dong Woo invented Pulse Transfer Controlling Device : * Random access memory for a computer Widely used between 1955 and 75. Magnetic toroids, cores, store data Current applications to two wires write data. Data is read by measuring a sensing wire current. Fast access speed Non-volatility Cheap Reliable (> vacuum tube) ® Used in a space shuttle. Read-out erases data. Accidental data loss * http://www.wikipedia.org/

Magnetic Bubble Memory In 1967, Andrew H. Bobeck invented a magnetic bubble memory : * Widely used between 1970s and 80s 4,096 bits / cm 2 Conventional stripe magnetic domains can be converted into cylindrical domains. The size of such cylindrical domains can be controlled by an external magnetic field. These domains disappear under a critical magnetic field. ® “Magnetic bubble” Large capacity Non-volatility Cheap Robust against vibration and dust Accidental data loss * http://www.nae.edu/21856.aspx ** http://www.wikipedia.org/

Magnetic Bubble Memory Operation Memory architecture : * * http://www.decodesystems.com/tib0203.html; ** http://www.wikipedia.org/

Floppy Disk In 1969, IBM introduced a flexible diskette : * Widely used until 1990s. 8-inch disk : 79.75 kB ~ 1.2 MB 5 ¼-inch disk : 110 kB ~ 1.2 MB 3 ½-inch disk : 264 kB ~ 200 MB Removable Basic Input / Output System (BIOS) compatible Non-volatility Cheap Fragile against vibration and dust Magnetic field and ultra-violet (UV) light High temperature and humidity * http://www.wikipedia.org/

Shugart Technology (Seagate Technology) Floppy Disk Sizes Specifications : * Disk diameter 8-inch 5.25-inch 3.5-inch Introduction 1970 ~ 1976 ~ 1980 ~ Developer IBM Shugart Technology (Seagate Technology) Sony Main demand Programme loading Miniaturisation High fidelity Coercivity 300 Oe 720 Oe Recording density 400 kB (800 kB) 1 MB 2 MB Track density 48 TPI 96 TPI 135 TPI Magnetic core Laminated Straddle Bulk * http://www.ceramic.or.jp/museum/contents/pdf/2007_5_01.pdf

Floppy Disk Media Media parts : * HD indicating hole Hub for rotation Shutter Plastic housing Polyester sheet to reduce friction against the housing Magnetically coated plastic disk Schematic data sector * http://www.wikipedia.org/

Magnetic permeability Floppy Disk Head A head core requires the following features : * Large saturation flux density Large magnetic permeability Small coercivity Wear-proof ferrites ferrites Magnetic permeability ferrites Frequency (kHz) Read / Write (R / W) head head Track width (TW) for ERASE Track width (TW) for R / W data Track width (TW) for R / W data TW for ERASE * http://www.ceramic.or.jp/museum/contents/pdf/2007_5_01.pdf

Partial Response, Maximum Likelihood A method to convert ambiguous signals to digital signals : * * http://www.datarecoverytools.co.uk/data-recovery-vocabulary/vocabulary-a-e/data-encoding-and-decoding-of-hard-disk/partial-response-maximum-likelihood-prml/

Floppy Disk Drive Drive parts : * * http://www.hardwaresecrets.com/fullimage.php?image=1532

Floppy Disk and CD-ROM Track configurations of a floppy disk and a CD-ROM disk : * Floppy disk CD-ROM disk Concentric Spiral Track starts from periphery Track starts from internal circumference Constant angular velocity (FD, HDD and MO) Constant linear velocity (CD, MD, DVD and BD) Small capacity Fast access speed Large capacity Slow access speed * http://www.kayoo.info/jyouhou-kiki/sozai/1506/index.html

Constant Angular / Linear Velocity Constant angular velocity : * Constant linear velocity : * Data tracks Data tracks Detecting laser / read head Detecting laser / read head Constant velocity Variable velocity * http://www.wikipedia.org/

SuperDisk In 1996, Matsushita (Panasonic) and Imation developed a SuperDisk : * Precise tracking by laser-positioning to grooves between the tracks. 3.5-inch disk : 120 ~ 240 MB FD32MB : 1.4 MB 2HD floppy → 32 MB tracks : 80 → 777 sectors :56 ~ 36 Backward compatibility BIOS (partially) compatible ×2 faster access speed than a FD Expensive * http://www.wikipedia.org/

Zip Drive In 1994, Iomega developed a Zip drive : * 3.7-inch disk media First product : 100 MB Later 250 and 750 MB Magnetic thin layer : Advanced super Thin layer & high Output Metal Media (ATOMM) developed by Fujifilm. Very fast access speed (1.0 Mbps) Cheap drive High data density Direct connectability with a Parallel / SCSI port Expensive media as compared with a MO Upward compatibility A 750-MB drive cannot write a 100-MB disk. “Click of death” Permanent damage to the head by hitting to the protector of head movement. * http://www.wikipedia.org/

Jaz Drive In 1995, Iomega developed a Jaz drive : * 3.5-inch disk : 1 GB Upward compatibility : 2 GB Fast access speed similar to a HDD (5.4 Mbps) Overheat Media stuck in a drive Metal slides introduces plastic debris. Noisy rotation Failure of anti-gyro system * http://www.wikipedia.org/

REV Drive In 2003, Iomega introduced a REV drive to replace a Jaz drive : * 2.5-inch disk : 35 GB Upward compatibility : 70 and 120 GB Fast access speed : 25 Mbps Dust-proof Anti-vibration 30-year life (> 1M times rewritability) Expensive * http://www.wikipedia.org/

Hierarchy of Information Storage For a Neumann machine, a central processing unit (CPU) controls the storages : * On-line / off-line Volatile / non-volatile For volatile memories, static / dynamic Read/write, read only or write once Random / sequential access Location, file or content addressable Destructive / non-destructive read * http://www.wikipedia.org/