[BC] Digital Storage

[Bruce Doerle]

Richard,

I kind of remember working with these drives in the mid-80's.  I had a Sperry XT (286) machine and later a AST 286.  Lost both in Liberia.  But you had to do a low level format first to mark the drive errors and then you could do the partition and high level format.  It was an all day job unless you had something do while it was formatting like wash and wax your car.

But I kind of remember the jump was from 5mb to 10 to 20 and then to 40mb.  I don't remember a 50.  Of course, I got tired of that process and went on to SCSI in 1990 with Seagate 80mb drives. 

Thanks for the reminder,

Bruce

>>> On 11/29/2010 at 2:04 PM, in message
<7.0.1.0.2.20101129120410.03f50700 at oldradio.com>, <RichardBJohnson at comcast.net>
wrote:
> 
> PC disk drives:
> 
> In the beginning... The first disk drives to go into a PC (actually an AT 
> because PCs only had floppies) was named for its interface, ST-506. You could 
> get these in any size as long as it was five megabytes! 
> http://en.wikipedia.org/wiki/ST-506 
> 
> Adaptec made adapter boards so PC users could also have hard disk drives. 
> They, too, had the ST-506 interface.
> 
> The ST-506 interface treated the hard disk like a floppy disk. Software on 
> the PC would actually seek to a certain track. These hard disks were quite 
> reliable and eventually their size was increased to 50 megabytes as the 
> number of cylinders, tracks, and heads were increased as technology matured. 
> The PC/AT under DOS could only directly access 33 megabytes of raw disk data 
> so the disk drives for PCs stagnated at that level for a while.
>