storage The first full-height 5.25 inch
hard disk drive for
personal computers, introduced in 1980 by Shugart Technology (now
Seagate Technology). The ST-506 stored up to 5 megabtyes after
formatting using MFM encoding. It transferred data at 625 kilobytes per second.
The ST-506 (like the ST-412) was interfaced to a computer via a
disk controller. The interface was a faster version of the Shugart Associates SA1000 interface, which was in turn based upon the
floppy disk drive interface. Two cables connected the controller to the disk. The 34-pin control cable controlled mechanical motion and data was read or written serially using two pins of the 20-pin data cable.
Other companies copied the interface, creating a universal
de facto standard that was further strengthened by its revision to support Seagate's 10 MB ST-412 drive that was adopted for the
IBM PC XT.
Around 1990,
SCSI and
ATA superseded ST-506. These eliminated the problems of matching controllers to drives by physically integrating a controller with the drive, allowing interleave ratios and other disk parameters to be optimised by the manufacturer rather than the system integrator.
Connector pin-out (https://www.gamesx.com/hwb/co_ST506.html).
(2007-03-06)