How Much Storage on a Floppy Disk

Secondary Storage

HARVEY M. DEITEL , BARBARA DEITEL , in An Introduction to Information Processing , 1986

Floppy Disks

Floppy disks , sometimes chosen flexible disks or diskettes, can store between a few hundred thousand and several million characters of data (Figures 6-17 and 6-18). It takes only nearly a tenth of a second for a floppy disk drive to remember any piece of data direct. The deejay'due south small size and low cost (only a few dollars each) helped spawn the personal computer revolution in the late 1970s.

The middle of a floppy disk, or floppy, is a circle of magnetic material (Figure 6-19). Information is recorded in circular tracks in plow divided into wedge-shaped sectors (Effigy 6-20). The hardware is designed to access the deejay by sector number. Disks may be hard-sectored or soft-sectored. On hard-sectored disks, sectors are physically marked past a serial of holes near the heart of the disk. On soft-sectored disks, sector locations are magnetically recorded on the disk. Recording this sector information is called formatting or initializing the disk.

Before the invention of floppy disks past Shugart Associates in 1972, personal computers used small cassette tapes (Effigy six-21), which take neither the speed nor reliability needed past calculator systems. Floppies are then reliable that some manufacturers certify that their disks are mistake-gratis at time of purchase and will remain mistake-free for ten million passes under a read/write head (See also Figures half dozen-22 and 6-23).

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File Management

William J. Buchanan BSc, CEng, PhD , in Software Development for Engineers , 1997

32.2.3 Formatting a deejay

A floppy disk must be formatted earlier it can shop files. Some disks are pre-formatted when they are purchased, but others required to be formatted before they are used. Care must be taken when formatting a disk as the current contents of the disk will be erased.

To format a disk outset insert information technology into the floppy disk drive. Next select Disk→Format disk … from the menu, equally shown in Figure 32.5. When this is selected Windows will prompt the user for the drive which the disk has been entered and the capacity of the disk. By default this is probable to exist gear up to A: and 1.44 MB (for a 3.five inch floppy disk drive on the A: bulldoze), respectively. If the bulldoze differs from the default or its format differs and then change the options by pulling down the Disk In or the Capacity options.

Figure 32.vi shows the main steps that are taken to format the disk. First the disk capacity and bulldoze name are prompted for. When these are correct the OK button is selected. Next a Format Disk window is displayed. Within this window the current condition of the deejay formatting performance is displayed (from 0 to 100% consummate). When complete, a window with a bulletin Creating root directory will be displayed. Afterwards this the formatted disks' capacity is displayed and the user is prompted as to whether another disk is to be formatted. If no more disks are to be formatted then the No option is selected else Yes is selected. Annotation that the Cancel option on any of the format status windows tin can be selected to cancel the format process.

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Computers and their application

Ian Robertson , in Mechanical Engineer's Reference Volume (Twelfth Edition) , 1994

iv.12.half dozen Floppy disk

The floppy disk, while having the four elements described above, was conceived as a simple, low-price device providing a moderate amount of random access dorsum-upward storage to microcomputers, word processors and small concern and technical minicomputers. As the name implies, the magnetic medium used is a flexible, magnetic oxide-coated diskette, which is contained in a foursquare envelope with apertures for the bulldoze spindle to engage a hole in the heart of the disk and for the read/write head to make contact with the disk. Diskettes are of three standard diameters, approximately 203 mm (8-inch), 133 mm (5 1/2-inch) and 89 mm (3 1/2-inch). The compactness and flexibility of the disk makes information technology very simple to handle and shop, and possible for information technology to exist sent by post.

One major simplification in the pattern of the floppy disk arrangement is the arrangement of the read/write head. This runs in contact with the disk surface during read/write operations and is retracted otherwise. This feature and the pick of disk blanket and the pressure loading of the head are such that, at the rotational speed of 360 rev/min, the vesture on the recording surface is minimal. Eventually, however, article of clothing and therefore mistake rate are such that the diskette may have to be replaced, copying the information onto a new diskette.

Capacities vary from the 256 kilobytes of the earliest drives, which record on one surface of the diskette only, to a figure of over ii megabytes on more recent units, almost of which utilize both surfaces of the diskette. Admission times, imposed past the rather slow head-positioning mechanism using a stepping motor, are in the range of 100-500 ms. Transfer rates are below 300 kilobytes per second.

Another simplification is in the area of operator controls. There are mostly no switches or status indicators, the simple action of moving a flap on the front end of the drive to load or removing the diskette beingness the only operator activeness. The disk motor spins all the time that a disk is nowadays.

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Optical Data Processing

Mir Mojtaba Mirsalehi , in Encyclopedia of Physical Scientific discipline and Technology (3rd Edition) , 2003

Vi.C.3.a Optical disks

Today, magnetic difficult disks and floppy disks are widely used in electronic computers. A relatively new medium for data storage is optical disks, where the information is recorded and read by a laser beam. The master reward of optical disks is their high storage capacity. A small three.five- or 5.5-in. Optical disk is capable of storing 30 to 200 Mbytes of information.

Optical disks are of two types: read-only disks and read–write (erasable) disks. The get-go type is useful for archival storage and storing information or instructions that do not demand to be inverse. In the second blazon, the recorded data tin can be erased or changed. This type of memory is needed for temporary data storage, such every bit in digital computing. Some of the materials used for nonerasable disks are tellurium, silver halide, photoresists, and photopolymers. Amongst the candidate materials for erasable disks, three groups are more promising. These are magneto-optic materials, phase-change materials, and thermoplastic materials.

Optical disks are at present used in some models of personal computers, and they are expected to become more common. Besides, optical disks accept been used for archival storage. Ii such systems accept been adult and installed by RCA for NASA and Rome Air Evolution Center in 1985. These are optical disk "jukebox" mass storage systems that provide direct access to any part of a stored data of 10¹³ bits within half-dozen sec. These systems have a cartridge storage module that contains 125 optical disks, each of 7.8 × ten¹⁰ $.25 storage chapters. This storage size is beyond the capacities that are currently available with other technologies.

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THERMAL PERFORMANCE Assay FOR ELEVEN CALIFORNIA PASSIVE SOLAR AND ENERGY CONSERVING HOUSES BASED ON ONE YEAR OF MONITORED DATA

Sukhbir Mahajan , ... Patrick Morandi , in Passive and Low Energy Compages , 1983

QUALITATIVE Assay OF INSTRUMENTED Information

The hourly data on cassette tapes was transferred to floppy discs and nine runway record for processing and plotting using other reckoner medium. I of the beginning steps in processing the data was to plot the output of various sensors for three to v day periods during winter and summer months. These plots provide qualitative information on the performance of the houses. As an example shown in Fig. 3 are plots of four sensors from the Santa Barbara house for ii articulate days followed by a cloudy solar day in January. This plot shows how the Trombe wall passive solar system response to solar inputs, the charging and discharging of the thermal mass, and occupant activities. The double peaks on the inside temperature plot are starting time, due to solar gain and the second, due to occupant activities such as cooking and utilise of appliances and the delayed rut pulse from the Trombe wall. Every bit expected the heat pulse through the Trombe wall arrives about eight hours later the acme solar gain. The transition from the two sunny days to the cloudy 24-hour interval is quite practiced and due mainly to the exponential disuse of the Trombe wall thermal mass temperature. Other qualitative plots which are used in this manner are the daily max-min temperature plots and the interior "binned" temperature bar graphs. With this level of information a good picture of how the house was operated and a qualitative understanding of the performance is possible.

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Motherboard Design

William Buchanan BSc (Hons), CEng, PhD , in Estimator Busses , 2000

5.1.four 82091AA (AIP)

The AIP device integrates the series ports, parallel ports and floppy disk interfaces. Figure 5.iii shows its connections and Figure 5.iv shows the interconnection between the AIP and the PIIX3 device. The OSC frequency is set to 14.218 xviii MHz. It can be seen that the range of interrupts for the serial, parallel and floppy disk drive is IRQ3, IRQ4, IRQ5, IRQ6 and IRQ7. Normally the settings are:

•: IRQ3 – secondary serial port (COM2/COM4).
•: IRQ4 – primary serial port (COM1/COM3).
•: RQ6 – floppy disk controller.
•: IRQ7 – parallel port (LPT ane).

Figure 5.iv shows the main connections between the TXC, PIIX3 and the AIP. It can be seen that the AIP uses many of the ISA connections (such as 0WS#, IOCHRDY, and and so on). The interface between the TCX and the PIIX3 defines the PCI bus and the interface between the PIIX3 and AIP defines some of the ISA signals.

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Computers

Owen Bishop , in Sympathize Electronics (Second Edition) , 2001

Disk drives

About computers have three kinds of disk drive. The floppy disk bulldoze stores information on a thin flexible plastic disk coated on one or both sides with a magnetic pic. Although the disk itself is floppy, and early on ones were enclosed in flimsy cardboard covers, most disks are nowadays enclosed in a stiff plastic embrace. The cover has a metallic shutter which slides dorsum automatically when the disk is inserted in the bulldoze to expose office of the disk surface to the magnetic head.

The principle is the same as that used when recording music on digital audio tape. The primary difference is that the data is recorded on twoscore concentric tracks and the magnetic caput moves radially to read or write each track. Each track is divided into sectors, each 1 being allocated to one particular program or fix of data. Longer programs or data tables may require more than i sector. There is a directory rail on the disk telling the estimator in which track and sector to look for each block of stored data and the magnetic head tin skip from runway to runway and sector to sector, finding the information that is required. A typical floppy disk tin can shop up to 1.4 megabytes of information.

Data can be read at rates of several hundred $.25 per second, but first the deejay must exist accelerated up to full speed (360 r.p.1000.), and the magnetic caput moved to the correct runway and sector. A typical access time is 200 milliseconds, which is much slower than the 25 to 150 nanosecond admission time of RAM or ROM.

A hd has 1 or more disks attached to the same spindle. The disks are made of non-magnetic metal and coated on both sides with a magnetic film. The principle of storage is the same only the magnetic heads are much closer to the motion-picture show. This is because the disks rotate at very high speeds (about 3600 revolutions per infinitesimal). This gives ascent to a thin layer of moving air close to the disk surface in which the magnetic head 'floats' without actually coming into contact with the disk. Since the head is closer to the deejay, it is possible to record data more densely: the tracks are closer together and the recorded bits closer together than on a floppy disk. Consequently, a typical difficult deejay drive stores several gigabytes (yard 1000000 bytes). Another advantage of the hard disk is that the high rate of spin reduces admission time to about 20 milliseconds. As the head is very close to the surface of the disk it is essential to exclude particles of dust or smoke. Hard drives are sealed during manufacture and can not commonly be opened by the user.

Compact disc drives are very like to CD players and work on the same principles. In fact, they are able to play ordinary music CDs through the sound card of the computer. The information stored on a CD is simply a series of 0 south and i due south. It may represent musical sounds but it could every bit well exist used for storing information of other kinds. In calculating terms, a CD stores most 600 megabytes of data. CDs have largely replaced floppy disks as a medium for distributing software. Near programs nowadays are too long to fit on a floppy deejay and in that location are other advantages likewise. A CD is unaffected by stray magnetic that tin so easily wipe the data from a floppy disk. Also, CDs cost much less to produce in quantity than floppy disks, so are platonic for large-scale distribution, on the covers of computer and other magazines, for example.

Like hd drives, CD drives are fast plenty to be used every bit memory storage devices for computers, the information existence accessed straight off the CD. The main difference is that CDs are read-but memory (CD-ROM). Still, CD- recordable drives may be used with special CD-R discs to write (but not re-write) data and play information technology back as many times as required. CDs are widely used in multimedia applied science. A disc can shop text, computer programs, photographs and diagrams, motion pictures and sound. These can exist accessed and loaded into the computer almost instantly. Very elaborate games with startling graphics are now available on CD-ROM just more serious applications of the technology include educational and reference discs.

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Computer Architecture

Morris Chang , in The Electrical Engineering science Handbook , 2005

Magnetic Disk Memory

Magnetic disk retentiveness is used to implement hard disks, standard floppy disks, and high-density floppy disks (due east.thou., Zip drive, Super drive). Hard disks are the nigh commonly used second retention devices considering of their low price, loftier speed, and high storage capacity. Hard disk drive drives are mass storage units that let read to and write from magnetic media; they consist of one or many thin disks that have magnetic coating, assuasive data to be recorded. The recording surface is divided into concentric tracks, and each runway is divided into segments called sectors. The set of tracks at a given radial position is referred to as a cylinder. One disk or more are then mountain on a spindle and rotate at a constant speed. To access the data, a two-pace procedure is required. Commencement, the read/write head moves beyond the rotating disk to the locating track. Then the caput waits until the correct sector is underneath it, and read/write is performed. The descriptions of magnetic disk memory devices are given as follows:

•: The hard disk bulldoze is the almost usually used mass storage device, as already stated. The size of today'south hard drives can vary from 14 inches (used in older mainframe computers) to i.8 in (used in laptop and portable computers). The most typical size used in a PC is iii.5 in, and the ones used in notebook computers are from ane.viii to 2.5 in. The rotating speed likewise varies depending on the interface used (discussed more in the bus interface section). For an integrated drive electronics (IDE) interface, the speed varies from 4500 rpm to 7200 rpm. For a small computer systems interface (SCSI), the speed can be as loftier equally x,800 rpm. The typical chapters varies from one gigabyte to tens of gigabytes (1 GB is 2³⁰ bytes).
•: The floppy deejay drive, besides known equally diskette, is a removable magnetic storage medium that allows recording of data. IBM showtime introduced it as a 8-in diskette in 1971. In the centre of 1970s, a 5.25 diskette was introduced. Today, the nigh commonly used floppy disks are 3.5 inches and take the capacity of 800 KB to 2.8 MB (with a standard of 1.44 MB).
•: The high-density floppy disk drive was beginning introduced in 1995. High-density floppy disks, while sharing a 3.5-in size with the standard floppy disks, are much faster and accept upward to 1 hundred times more capacity than the standard floppy disks. One instance is the Nothing drive, produced by Iomega. Each Zip disk is capable of storing upward to 100 MB of information. Similarly, Imation, a subsidiary of 3 M, also manufactures the Super disk (besides known equally the LS 120) that tin store upwardly to 120 MB of information.
•: The removable hard disk drive has been at work in the mainframe reckoner industry since the 1950s. Dorsum then, the drive mechanism was extremely expensive; therefore, different applications would use different removable disks, during plan execution. In the 1980s, removable difficult drive was used for backup purposes. The capacity then was 44 MB. Present, removable disks come up in diverse capacities from 1 gigabyte up to several gigabytes.
•: The redundant array of inexpensive disks (RAID) was introduced past David Patterson and other researchers at the University of California, Berkeley, in the late 1980s. It is a method where two or more disks are used to store data. Data can be read simultaneously from more than one drive, which improves the functioning. Data tin besides be split among all drives in bits, bytes, or blocks. Typically two or more disks are continued together. A single controller can exist used to connect the drives then that they function together as ane drive. For extra safety, a second interface controller can exist installed to duplex the drives and increase read performance. The major advantages of RAID are improvement in reliability and protection for data in mass storage systems.

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The hardware/software integration phase

Arnold South. Berger PhD , in Debugging Embedded and Existent-Time Systems , 2020

The instance of the nonstandard hard disk drive interface

Hewlett-Packard introduced its Vectra Portable CS computer in 1987, and it independent a floppy deejay drive and a 20 MB, 3.v″ hard drive. The company had high hopes for the portable, only it failed in the market. Here's the description from the HP Computer Museum [two]:

The Vectra Portable CS was the portable version of the Vectra CS. The Portable CS had a big LCD screen too as CGA adaptor for apply with an external monitor. The Portable was offered in two mass storage configurations: dual 3.v inch (ane.44 MB) floppy disc drives - P/North D1001A, or a floppy disc drive and a xx MB hard disc drive - P/N D1009A. The Portable CS did not succeed due to its large size (much larger than the Portable Plus), relatively high toll and non-standard media (3.5 inch discs).

The Portable Vectra CS was introduced on September 1, 1987. Information technology was discontinued on May 1, 1989.

The company had high hopes of selling the hard drive as an OEM production to other computer manufacturers considering it was one of the first hard drives out in the 3.5″ form cistron. Rather than adopt the industry standard integrated drive electronics (IDE) interface, developed by Compaq and Western Digital in 1986, they designed an interface that used a 40-pin connector, simply otherwise, was entirely dissimilar. As a result, the drive was never adopted past other manufacturers and HP discontinued manufacturing presently later. The lesson? Standards thing.

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Assembly Costing

K.G. Swift , J.D. Booker , in Manufacturing Process Pick Handbook , 2013

13.iv.2 Floppy Disk

This 2d case written report is concerned with the assembly time and cost of a one.44 Mb floppy disk for use with a personal calculator. Although this product is well-nigh outmoded in this digital age, information technology is a useful production line to further demonstrate the methodology for costing assemblies. Figure 13.8 shows the component parts.

The results are shown together with the assembly structure diagram in Effigy 13.9 and a full assembly costing analysis is provided in Figure thirteen.10. The full assembly toll of the floppy disk per unit is constitute to be approximately ≤0.24 ($0.39) and the calculated assembly fourth dimension is approximately 52 seconds. Annotation that a relaxation is not taken into account and the fact that the operator would be working in a clean environment room wearing protective clothing to stop contagion.

The fourth dimension contribution of each associates operation compared to the overall associates time is shown as a percentage in Figure 13.11. A Pareto chart format is used with the greatest contribution to the total assembly time to the left. As highlighted, locating the front case sub-associates on to the back case sub-assembly whilst the spring is in position is a hard and time-consuming assembly task. Screen placement and spring plumbing equipment are two other operations of a time-consuming nature. In order to improve the ease of assembly of a detail concept design and reduce assembly costs, the use of the metrics in this manner can assist identify potentially problematic areas and give guidance on redesign through reference to the charts provided.

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