By Adam Stowell

1. Storage Media Through The Years By Adam Stowell

2. Introduction • The following presentation will escort you through the more recent history of storage media. Starting with the introduction of magnetic recording to what lies ahead in the future. • Also be on the lookout for the Gwyndolyn Largebottom symbol to give you a little more information and pictures.

3. The Early Years • Toward the end of the Industrial Age is where our journey begins with an American mechanical engineer named Oberlin Smith. He came up with the idea of recording electrical signals produced by the telephone on a steel wire. The idea was presented to him after a visit to Thomas A. Edison’s laboratory. After spending 10 months on a reel-to-reel recording system, Smith filed a “patent caveat”, but not a formal patent, deciding not to pursue the idea. He did publish the concept in the journal, “Electrical World”.

4. Oberlin Smith • Gwyndolyn Largebottom says that “Smith had 70 patents ranging from devices to extract boiling eggs at a certain time to inventing or improving die presses.”

5. The Next Step • Picking up where Smith left off, Valdemar Poulsen started experimenting with recording electrical signals on steel wire. By the end of 1898 he filed a patent with the Danish Patent Office for the Telegraphone. In the UK the following year a patent was file that foresaw the future of today’s disks and tapes. "Instead of a cylinder with a helical steel wire there may be uses as a receiving device a steel band, supported if necessary on an insulating material and brought under the action of an electromagnet. Such an arrangement has the advantage that a steel band of an desired length may be used. Instead of a cylinder there may be used a disk of magnetisable material over which the electromagnet may be conducted spirally; or a sheet or strip of some insulating material such as paper may be cover with a magnetisable metallic dust and may be used as the magnetisable surface. With the aid of such a strip which may be folded, a message received at any place provided with the new apparatus may be sent to another place where it may be repeated by passing the strip through the apparatus at that place."

6. Valdemar Poulsen • Gwyndolyn Largebottom says “Poulsen also designed spark transmitters and other inventions. He won honors and medals from institutions in his native Denmark.”

7. Williams tube Core memory Plated wire memory Delay line memory Magnetic Tape Reel of 1/2" 9-Track Tape (1970) DECTape Cassette and cartridge tapes Magnetic drum storage English Electric Deuce Drum (1957) More Advances

8. Moving Head Disk Drive • In 1955, commercial computers used tubes for logic, cores for short-term memory, head-per-track drums for intermediate storage and tapes on reels for longer-term memory. • “The first functional prototype weighed in at one ton and took up 300 cubic feet. Fifty double-sided aluminum magnetic disks, each 24-inches in diameter, rotated at 1200 revolutions per minute on a common shaft, using externally pressurized air fed through the read/write heads to support the heads over a set of 24-inch disks. The drive's capacity was 5 megabytes, an unheard of accomplishment for its time.” • The prototype was called the IBM 305 RAMAC (Random Access Method of Accounting and Control).

9. Reynold Johnson • In addition to his work on the RAMAC, Rey Johnson also distinguished himself in 1934 as the inventor of the mark-sense reader. The media for this device is familiar to the generations of students who took tests by filling in the space between the vertical dotted lines on the test firm, using the mandatory #2 pencil.

10. Recent Advances • Burroughs ILLIAC IV 80MB Disk Drive (1972) • Disk packs and cartridges • IBM 1311 Disk pack drive (1963) • Diablo Disk Cartridge (1973) • Flexible Disk Drive:The IBM "Minnow" • Magnetic cards • Intel EPROM (1975-85)

11. Diskettes (Floppy Disks) • In 1969 IBM was the first to manufacture the diskette. It was used to load programs into the controller of a rigid disk drive. It was released publicly in 1971. It was given the nickname “floppy disk” due to its ability to bend. • “First designed to use 8" diameter media, 5.25" media (1976) and then 3.5" media (1981) became predominant as improved technology increased storage capacity per unit area and form factors shrank. Various other sizes were offered, but were not adopted by the computer industry. The standards fights were brutal! • When first introduced, capacity was about 100 kilobytes (KB) per disk for the 8" diskette. Typical 5.25" diskettes offered 360 KB, then 1.2 or 1.6 megabytes (MB). The 3.5" units were typically .7 or 1.4 MB. Higher capacity variants were available, but never caught on because of expense and standards disputes.”

12. Optical Disk Drives • “Optical disk drives use lasers to read and write on the disk surface. Attempts to design optical drives began in the 1960s, but the CD-ROM, which appeared in the 1980s, was the first successful optical storage device for computers. Originally a read-only device, read-write versions appeared in the early 1990s. The 500 to 700 MB capacity of CD-ROM made it a success as a distribution medium for software, which was undergoing explosive growth in memory requirements.” • “DVD drives, also laser read and written, were the next major success. With 4.7 GB per side, the disks were suitable for storing a digitized feature-length movie. But standards disputes and royalty issues delayed the introduction of writable DVD formats, and as of early 2002there is yet no universal format.”

13. Recent Advances Cont. • Flash memory • Specialized Alphabets and Symbol Sets • Magnetic Ink Character Recognition • Automating storage

14. Future Storage • Advanced magnetic recording media • Magnetic Random Access Memory • Atomic Force Microscopy (AFM) and Thermomechanical Storage • DNA Storage • Holographic storage • Quantum-level storage

15. The End Click on disk to return to home page