Search results
Results from the WOW.Com Content Network
8-inch floppy disk, inserted in drive, (3½-inch floppy diskette, in front, shown for scale) 3½-inch, high-density floppy diskettes with adhesive labels affixed The first commercial floppy disks, developed in the late 1960s, were 8 inches (203.2 mm) in diameter; [4] [5] they became commercially available in 1971 as a component of IBM products and both drives and disks were then sold ...
Drawings from IBM Floppy Disk Drive Patents. IBM's decision in the late 1960s to use semiconductor memory as the writeable control store for future systems and control units created a requirement for an inexpensive and reliable read only device and associated medium to store and ship the control store's microprogram and at system power on to load the microprogram into the control store.
As a result, early floppy drives required jumpers to be set on the drive to tell it which controller commands it should receive. When introducing the PC, IBM sliced the cable between the first and second drive, and twisted seven of the conductors, effectively flipping the four conductors which specifically addressed the first or second drive.
A disk drive is a device implementing such a storage mechanism. Notable types are hard disk drives (HDD), containing one or more non-removable rigid platters; the floppy disk drive (FDD) and its removable floppy disk; and various optical disc drives (ODD) and associated optical disc media.
drive: 1, diskette: 2 16 8 512 2× 64 kB 270 GCR (4/5) Internally based on FDU-250 Micro Floppy Disk Drive Unit [2] Thomson: 5 1 ⁄ 4 inch Single 1 40 16 128 80 kB 300 FM Thomson UD90.070 Double 2 256 320 kB MFM Thomson DD90-320 [NB 17] 3 1 ⁄ 2 inch Double 1 80 16 256 320 kB 300 MFM Thomson TO9, Thomson DD09-350 Double 2 640 kB
IBM manufactured 8-inch floppy disk drives from 1969 until the mid-1980s, but did not become a significant manufacturer of smaller-sized, 5.25- or 3.5-inch floppy disk drives (the dimension refers to the diameter of the floppy disk, not the size of the drive). [4]
The original Zip drive has a maximum data transfer rate of about 1.4 MB/s (comparable to 8× CD-R; although some connection methods are slower, down to approximately 50 kB/s for maximum-compatibility parallel "nibble" mode) and a seek time of 28 ms on average, compared to a standard 1.44 MB floppy's effective ≈16 kB/s and ≈200 ms average ...
A floppy-disk controller (FDC) is a hardware component that directs and controls reading from and writing to a computer's floppy disk drive (FDD). It has evolved from a discrete set of components on one or more circuit boards to a special-purpose integrated circuit (IC or "chip") or a component thereof.