SONY宣布停产3.5寸软盘及相关设备

产线将完全关闭

至此从1981年到2010年，3.5寸盘享年30

引用:

原帖由 ooo 于 2010-4-29 06:46 发表
posted by wap

磁盘和软驱是SQNY发明的？我记得好像是IBM…生产了三十年SQNY软盘算是一个时代的记忆…话说SQNY在IT行业都造些啥？软驱、光驱、显示器，组装笔记本？

introduced their own small-format 90.0 mm × 94.0 mm disk, similar to the others but somewhat simpler in construction than the AmDisk 3-inch floppy.[39] The first computer to use this format was Sony's SMC 70[40] of 1982. Other than Hewlett-Packard's HP-150 of 1983 and Sony's MSX computers that year, this format suffered from a similar fate as the other new formats; the 5¼-inch format simply had too much market share.

Things changed dramatically when in 1982 the Microfloppy Industry Committee, a consortium ultimately of 23 media companies, agreed upon a 3½-inch media specification based upon but differing from the original Sony design[41]. The first drives compatible with this new media specification were shipped in early 1983[42]. In 1984 Apple Computer selected the format for their new Macintosh computers.[43] Then, in 1985 Atari adopted it for their new ST line, and Commodore for their new Amiga. By 1988 the 3½-inch was outselling the 5¼-inch[44].

Note that the term "3½-inch" or "3.5 inch" disk was primarily targeted at the non-metric US market and was rounded from the actual metric size of 90 mm used internationally.

The 3½-inch disks had, by way of their rigid case's slide-in-place metal cover, the significant advantage of being much better protected against unintended physical contact with the disk surface than 5¼-inch disks when the disk was handled outside the disk drive. When the disk was inserted, a part inside the drive moved the metal cover aside, giving the drive's read/write heads the necessary access to the magnetic recording surfaces. Adding the slide mechanism resulted in a slight departure from the previous square outline. The irregular, rectangular shape had the additional merit that it made it impossible to insert the disk sideways by mistake as had indeed been possible with earlier formats.

The shutter mechanism was not without its problems, however. On old or roughly treated disks the shutter could bend away from the disk. This made it vulnerable to being ripped off completely (which does not damage the disk itself but does leave it much more vulnerable to dust), or worse, catching inside a drive and possibly either getting stuck inside or damaging the drive.

Like the 5¼-inch, the 3½-inch disk underwent an evolution of its own. When Apple introduced the Macintosh in 1984, it used single-sided 3½-inch disk drives with an advertised capacity of 400 kB. The encoding technique used by these drives was known as GCR, or Group Code Recording (similar recording methods were used by Commodore on its 5¼ inch drives and Sirius Computer in its Victor 9000 non PC compatible MS-Dos machine). Somewhat later, PC-compatible machines began using single-sided 3½-inch disks with an advertised capacity of 360 kB (the same as a double-sided 5¼-inch disk), and a different, incompatible recording format called MFM (Modified Frequency Modulation). GCR and MFM drives (and their formatted disks) were incompatible, although the physical disks were the same. In 1986, Apple introduced double-sided, 800 kB disks, still using GCR, and around the same time, 720 kB double-sided double-density MFM disks began to appear on PC-compatibles.[citation needed]

A newer and better, MFM-based, "high-density" format, displayed as "HD" on the disks themselves and storing 1440 kB of data, was introduced in 1987. These HD disks had an extra hole in the case on the opposite side of the write-protect notch. IBM used this format on their PS/2 series introduced in 1987. Apple started using "HD" in 1988, on the Macintosh IIx, and the HD floppy drive soon became universal on virtually all Macintosh and PC hardware. Apple's FDHD (Floppy Disk High Density) drive was capable of reading and writing both GCR and MFM formatted disks, and thus made it relatively easy to exchange files with PC users. Apple later marketed this drive as the SuperDrive. Interestingly, Apple began using the SuperDrive brand name again around 2003 to denote their all-formats CD/DVD reader/writer.[citation needed]

Besides Sony, Apple was the first major manufacturer to start selling computers with 3½-inch disk drives as well as the first to stop shipping those in 1998 with introduction of iMac.

Another advance in the oxide coatings allowed for a new "extended-density" ("ED" format at 2880 kB introduced on the NeXTcube and NeXTstation in 1991, and on IBM PS/2 model 57 also in 1991, but by the time it was available it was already too small in capacity to be a useful advance over the HD format and never became widely used. The 3½-inch drives sold more than a decade later still use the same 1.44 MB HD format that was standardized in 1989, in ISO 9529-1,2.


这垃圾居然灭了当时同时竞争的日立/松下/Maxell的三寸盘方案和三菱的方案

真是罪该万死

引用:

原帖由 ooo 于 2010-4-29 06:46 发表
posted by wap

话说SQNY在IT行业都造些啥？软驱、光驱、显示器，组装笔记本？

SONY居然是全球排名前十的半导体厂商

真是罪该万死