non-SCSI disks on a SCSI disk interface (was Re: Space, the next frontier)

From: Don Maslin <donm_at_cts.com>
Date: Wed May 26 23:56:22 1999

On Wed, 26 May 1999, Allison J Parent wrote:

> <Someone should correct me if I'm wrong (I'd be interested in knowing that
> <I'm wrong!), but the largest capacity MFM geometry is that of the Maxtor
> <XT2190 (1024 cylinders * 15 heads), giving you just under 150 Mbytes (M=10*
> <after formatting at 19 sectors/track. And the RLL version gets
> <another 30% or so of capacity.
>
> The 2190 is 1224*15. However the number of cylinders can be increased (it
> was controller limit not the drive) the limit, I think is closer to
> 4096*16*18*512 or roughly over 600mb. The problem is that RLL with the

Do you mean that Maxtor used only about the first third of the available
platter for data? That seems like a bit of a waste. I do recall - years
back - discussion about how the XT1085 could be extended, but not by a
factor of three!
                                                 - don

> higher bit packing, and EDSI with the higher data rates put more data on
> a square inch of media and make more sense than pushing the mechanics of
> the drive.
>
> <Of course, large embedded-controller SCSI drives are readily available on t
> <surplus market these days. 9 Gbyte drives start below $150.00, and
> <2 Gbyte drives seem to get around $40.
>
> And they are small too!
>
> Allison
>
>
Received on Wed May 26 1999 - 23:56:22 BST