Oral History Panel on 5.25 and 3.5 Inch Floppy Drives
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Floppy Disk - Wikipedia, the Free Encyclopedia Page 1 of 22
Line printer - Wikipedia, the free encyclopedia Page 1 of 5 Line printer From Wikipedia, the free encyclopedia The line printer is a form of high speed impact printer in which one line of type is printed at a time. They are mostly associated with the early days of computing, but the technology is still in use. Print speeds of 600 to 1200 lines-per-minute (approximately 10 to 20 pages per minute) were common. Contents 1 Designs 1.1 Drum printer 1.2 Chain (train) printer 1.2.1 Band printer 1.3 Bar printer 1.4 Comb printer 2 Paper (forms) handling IBM 1403 line printer, the classic line printer of 3 Origins the mainframe era. 4 Current applications 5 See also 6 References Designs Four principal designs existed: Drum printers Chain (train) printers Bar printers Comb printers Drum printer In a typical drum printer design, a fixed font character set is engraved onto the periphery of a number of print wheels, the number matching the number of columns (letters in a line) the printer could print. The wheels, joined to form a large drum (cylinder), spin at high speed and paper and an inked ribbon is stepped (moved) past the print position. As the desired character for each column passes the print position, a hammer strikes the paper from the rear and presses the paper against the ribbon and the drum, causing the desired character to be recorded on the continuous paper. Because the drum carrying the letterforms Drum Printer (characters) remains in constant motion, the strike-and-retreat http://en.wikipedia.org/wiki/Line_printer 2010-12-03 Line printer - Wikipedia, the free encyclopedia Page 2 of 5 action of the hammers had to be very fast. -
Timeline of Computer History
Timeline of Computer History By Year By Category Search AI & Robotics (55) Computers (145) Graphics & Games (48) Memory & Storage (61)(61) Networking & The Popular Culture (50) Software & Languages (60) Manchester Mark I Williams- 1947 Kilburn tube EDSAC 1949 Manchester Mark I Williams-Kilburn tube At Manchester University, Freddie Williams and Tom Kilburn develop the Williams-Kilburn tube. The tube, tested in 1947, was the first high-speed, entirely electronic memory. It used a cathode ray tube (similar to an analog TV picture tube) to store bits as dots on the screen’s surface. Each dot lasted a fraction of a second before fading so the information was constantly refreshed. Information was read by a metal pickup plate that would detect a change in electrical charge. Maurice Wilkes with EDSAC Maurice Wilkes and his team at the University of Cambrid construct the Electronic Delay Storage Automatic Calcula (EDSAC). EDSAC, a stored program computer, used me delay line memory. Wilkes had attended the University of Pennsylvania's Moore School of Engineering summer sessions about the ENIAC in 1946 and shortly thereafter Magnetic drum memory began work on the EDSAC. 1950 MIT - Magnetic core memory ERA founders with various magnetic drum memories Eager to enhance America’s codebreaking capabilities, the US Navy contracts with Engineering Research Associates (ERA) for a stored program computer. The result was Atlas, completed in 1950. Atlas used magnetic drum memory, which stored information on the outside of a rotating cylinder coated with ferromagnetic material and circled by read/write heads in Jay Forrester holding early core memory plane fixed positions. -
Oral History Panel on HDD Transition for Personal Computers
Oral History Panel on HDD Transition for Personal Computers Interviewed by: Jim Porter Recorded: August 24, 2006 Mountain View, California CHM Reference number: X3701.2007 © 2006 Computer History Museum Oral History Panel on HDD Transition Jim Porter: We’re here today to discuss the transition in the disk drive industry from those big disks that were used for all kinds of things from mainframes to mini-computers to what we call small business systems the size of a desk, etcetera, which were there in the 1960s and up into the 1970s, that transitioned to those smaller disk drives. It started by going down a little bit to 8-inch disk drives, which are not that big a deal. But we’re here today basically to talk about that transition to 5-1/4 inch hard disk drives. Why it happened, how it happened, and its significance to the industry. But to start, I’d like to ask each of these very interesting people we have here on the panel today to give us a little bit of background on each of them. Let’s start with you Terry Johnson. Terry Johnson: Okay, basically, just to give you a little background, I basically got a... Porter: Oh, you dropped your mike. You dropped your sound system. <laughs> Johnson: I got a Masters degree at UC Berkeley in about 1982. And, excuse me. 1962. Porter: You only lost two decades. Johnson: Yeah, right. And went to work for IBM in 1963, and I worked at IBM at the San Jose facility at Monterey and Cottle Roads. -
The Floppy Disk Originated at IBM by Alan Shugart and His Team Back in 1967
The floppy disk originated at IBM by Alan Shugart and his team back in 1967. Shugart later founded the Shugart Associates in 1973i which dominated the 8-inch floppy disk drive market in the late 1070s. After resigning as CEO of Shugart Associates that was bought out by Xerox, he started another company with Finis Conner in 1979 called Shugart Technology. Because of Xerox copyright infringements on Shugart Associates, the name later changed to what we know as Seagate Technology. It was there that he 1 ii evolved the 8-inch drive to the 5 ⁄4-inch mini-floppy floppy disk drive in 1976 . There is an interesting story that goes behind the change of the floppy disk drive. It has been rumoured 1 that the 5 ⁄4-inch size was chosen because of a complaint made by a customer during a focus group meeting about the size of the disk. According to one of the sales managers at Seagate, the President and Shugart himself sat down with a customer to discuss their 8-inch drive product. When the customer was asked what the size should be, the customer pointed to a napkin on the table and said, "About that 1 size". They returned to their lab with the napkin and designed the 5 ⁄4-inch drive. The commercial model, SA 400, stored 110 kilobytes and sold for 45$ for ten diskettes. This model of the floppy disk was their best selling product with shipments of up to 4000 drives a dayiii. At Seagate, they also produced the 5 MB hard disk drive, in 1980, which fit the 5.25-inch form factor of the Shugart mini-floppy drive. -
Hardware and Peripherals
Part V Bits and Bytes. 17/1 17/2 Part V Bits and Bytes Blank page. Chapter 17 Hardware and Peripherals 17.1 ... Memory The microprocessor was a significant key to lowering the cost of the personal computer. However the other key and an equally important one was low-cost semiconductor memory. Semiconductor memory started replacing magnetic core memory around 1967. Their are two types of semiconductor Random Access Memory (RAM). Dynamic RAM (DRAM) requires periodic refresh of the memory contents and Static RAM (SRAM) retains the contents without refresh. Both types of RAM loose their contents when the power is turned off. Read only memory (ROM) retains its contents once it is programmed, even when the power is turned off. The first commercial 1K metal oxide semiconductor DRAM was the Intel 1103 released in October 1970. This chip had a pivotal role in undercutting the price and replacement of core memory. Intel continued to improve DRAM capacities with the release of the 4K 2107 chip in 1972 and the 16K 2117 chip in 1977. However, competitive challenges from Japanese companies, would have a significant impact on Intel and other North American producers of memory chips. Japan decided to make a strategic investment in the semiconductor memory industry around in the late 1970’s. The effect of this was the first open market release of a 64K DRAM chip by Fujitsu Limited in 1979, and introduction of the first 1-megabit DRAM chip by the Toshiba Corporation in 1985. A number of other factors contributed to the dominance of Japanese manufacturers in the 1980’s. -
Published by : Paper Works Computers P.O
-- Welcome to -- e e (tm) GUIDE TO HARD DRIVES, FLOPPY DRIVES, OPTICAL DRIVES, DRIVE CONTROLLERS & HOST ADAPTERS. er. • Copyright 1989, 1994 by F.Robert Falbo << All Rights Reserved >> TheRef (tm) is a trademark of F.Robert Falbo This document is Copyright 1994 by F.Robert Falbo, ALL RIGHTS RESERVED Published By : Paper Works Computers P.O. BOX 9393 ALLENTOWN, PA 18105 - 9393 Table Of Contents Section One Diagrams Section Two Controller Layouts Section Three Controller Specs Section Four Floppy Drive Specs Section Five Hard Drive Specs Section Six Optical Drive Specs Section Seven Manufacturer Directory D Diagrams Floppy Cables Hard Drive Cables Terminators I [ DIAGRAMS.DOC supplement to TheRef(tm) Drive & controller Listing In "publishing" TheRef(tm), I've often been asked the difference between the types of drive controllers and recording methods. I'm not going to get into that in this document, as it would require a good sized doc. of it's own. What I have suppl.ied are diagrams of the different connectors associated with the technology today. frf CABLES controller Drive 2(or none) Drive 1 1 Pins 10-16 are twisted FLOPPY cable : : ==========! ; =====~!~======! ; with twist :: before the =========== =============xx== connector. (control & :: =========== ================= data, 34 pin) :: =========== ================= (7 wires) Pins 25-29 are twisted :!;!2D:i!:DI 1 :: ~~~~~~~;~~~~~~~; before the cable w/twist :: ----------- -------------xx-- connector. (control) :: =========== ================= (5 wires) (no twists) Each drive :;!20:1!:DI 1 :: ~~~~~~~~~~~~~~~~~~~~~11~ has it's II own data (data, 20 pin) :: ================================ R cable IMPORTANT NOTE: Pin #1 on any drive cable SHOULD be indicated by a a colored stripe. If you should find the stripe by connector pin 34 (or 20), inspect the whole cable VERY throughly! DRIVE SELECT For both Floppy and Hard drives, when the 34 pin JUMPERS: cable has a twist, the device number should be set to the second position.