This caused a very big problem, the first 8-bit processors like the MOS 6502, the Motorola 6800, the Zilog Z80 or the Intel 8080 could address 16 bits of memory and therefore 64 KB, it is very little today. At that time, RAM was very expensive, but it was the only way to run programs because it was not possible to perform random access with a tape drive.
Therefore, a format which would allow random access to data without having to load all of the contents of the floppy disks into the computer’s RAM memory quickly became necessary and therefore only the necessary items were loaded into memory. The answer came with floppy disks, but their origin dates back to long before the birth of the first personal computers.
The origin of the floppy disk
The origin of the floppy disk can be found in the IBM System / 370, a family of IBM mainframes launched in 1970 and where one of the challenges they wanted to solve was the introduction of programs in a fast and inexpensive format. . The engineer in charge of this task was Alan Shugart who in 1967 began work on what would become the first floppy disk drive and the first 8 inch floppy disk.
In 1972 and outside of IBM, Shugart created the Memorex 650, with a much smaller size than that used in the System / 370 and with the ability to be connected to any type of computer, floppy disks of this device could store up to 175 KB of data. However, it was also not the first floppy disk drive for a personal computer.
In 1976 with the emergence of the Altair 8800 and the creation of the S-100 standard which allowed electronics enthusiasts to create personal computers at Shugart Associates, without its founder, they decided to create a unit of 8 inches, but they were convinced of it. an 8 inch unit was too big so they ended up inventing a downsized 5.25 inch version with a capacity of 110KB and a price tag of $ 390.
The unit was called SA-400 and its popularity among users of S-100 systems was such that they had to ask the Japanese manufacturer Matsushita to build them. They were adopted not only by the emerging world of the personal computer, but also mainframes and minicomputers, which is why a standard was born in the world of computing.
The floppy disk reaches the homes
The first mass computer to have a successful commercial floppy disk drive was the Apple II. Although I do not carry this storage unit as standard, its users had to purchase the unit separately, as in its original concept the computer used tape drives, but it soon became apparent that they were a limiting factor.
Apple wasn’t alone in developing its own floppy drive for its computer, Commodore did the same with its PET, but its floppy drives were complex, expensive, and had a mechanism that made them extremely slow. In any case, building such a unit without knowledge was not easy, as only the hardware of the controller could be as complex as that of a computer and in some cases if you were not careful it could be just as expensive.
In the case of the Apple II Disk, the design of the controller board was done by Steve Wozniak, who had previously designed the computer hardware and specialized in creating designs with fewer circuits, thanks to it instead. to copy Shugart’s design had their own and with a file system that allowed them to store 113KB per 5.25 floppy disk, while the SA-400 stored 90KB.
The Apple Disk II completely transformed Apple, enabling software that would otherwise have been impossible. They weren’t the only ones with a floppy drive, since as we have seen the S-100 systems used them, but in Cupertino it was a company organized with the aim of supplanting IBM. Big Blue’s response? The first home PC, the 5150 came with a 5.25 inch floppy disk drive like the SA-400 and Apple Disk II.
The three and a half inch floppy disk
The most popular floppy disk format, however, was 3.5-inch. Which was invented by SONY in 1980 and became popular over time, being its biggest improvement over its predecessors, its size, which allowed a floppy disk to be carried in a shirt pocket. In addition, it has reduced the size and complexity of disk drives in computers, allowing easy integration.
The format could initially store 360 kb of information, a significant jump in capacity to then evolve to 720 kb with the use of the double density format and duplicate again with 1440 kb of information per floppy disk. The form factor in each generation was retained, but floppy disk drives were not compatible with newer data encoding formats, so to use a larger capacity floppy disk it was necessary to change drives.
It was the last major standard, although years later other attempts to replace it appeared, but the CD-ROM eventually replaced its use. More when it got to the point where it was needed due to the huge amount of floppy disks that were needed.
This is what a floppy disk looks like inside
Floppy disks have come in different sizes, but the most popular is undoubtedly the 3.5-inch, which has become the common storage format not only for the PC, but also for the Apple Macintosh, the Commodore Amiga, the Atari ST, the Japanese MSX standard. and many more. This is why we took it as a reference.
The first important part is the head, when inserting the floppy disk into the drive, it moves to the side, giving access to the read and write head so that it can access or modify the data .
The second piece is the floppy disk, which stores track information in the same way as a hard drive, each track is a concentric circle on the disc. Regarding the size of each sector, it is not the same on all the tracks and the access speed either. Therefore, if it is necessary to access a different track than that found by the read and write head of the floppy disk drive, then there will be a delay in the data access time due to the timing. where the head is placed.
In the middle of the magnetic disk we have the bracket to which the spin motor that will spin the floppy disk will be anchored, which is essential for the head to be able to access all of the contents of the floppy disk without problems.
Finally, we have the plastic case and a paper disk, the former protects the data from electromagnetic interactions and the effects of sunlight. The second is responsible for preventing the magnetic disk from touching the case while it is spinning, which could damage it.
The components of a floppy disk drive
A floppy disk drive or floppy disk drive, regardless of its size, has the following components:
- Parent: It is a PCB that includes all the circuits responsible for receiving requests from the CPU, controlling the mechanical elements of the unit, and converting the obtained data into a signal that the system processor can understand.
- Central motor: is responsible for the rotation of the magnetic disk in the central part of the floppy disk. The speed in revolutions per minute depends on the design of each unit, although it is usually between 300 and 360 revolutions per minute.
- Writing and writing heads: It is the person in charge of reading the data of the sector for their subsequent coding and their digitization by the controller.
- Step-by-step engine : the second floppy disk motor is the one that allows the head to move forward through the different sectors of the floppy disk, so that it lands as quickly as possible on the appropriate track.
- Mechanical housing: this is the box where all of the previously described items are placed in an orderly fashion, not only protects against system vibration, but also provides mechanisms for inserting and ejecting floppy disks.
Is the floppy disk still in use?
Well yes, oddly enough, floppy disks are still in use, but not in terms of home or business users, but rather at the state level where several countries have even come to create their own proprietary variants to store the data. And it is that information stored digitally decades ago continues to be stored in these formats, especially in countries where some crimes have no expiration date and information stored on floppy disks is evidence. important.
Although little by little the various administrations of the world are emptying said data into storage formats of greater capacity, durable and reliable, the work that exists is titanic, since it is not only a question of emptying the data, but also to keep the contents intact. Although being a format with problems when it comes to maintaining information for the long term, the transition started a long time ago, but it is so complex that some countries as Japan completed it at the end of 2021 and some they are still in progress.
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