[Coco] hard drive questions

[L. Curtis Boyle]

On Mon, 12 Jun 2006 18:45:07 -0600, Bob Devries <devries.bob at gmail.com>  
wrote:

> Curtis said:
>>     An RLL drive would probably be the old 2 cable XT style, wouldn't  
>> it?
>
> Some SCSI and IDE drives are quoted as using RLL encoding *internally*.  
> RLL is a compression technique which is also used in some picture  
> storage methods. The "2,7" refers to the amount of compression IIRC.

    Yes, there were two versions of RLL for the old XT standard hard drives  
- one had 1/2 again as many sectors per track (like mine), and the other  
was half again as many tracks. The Compuserve RLE graphics standard was  
also run length encoded, although I think it was a much simpler algorithm  
than used by the drives.
     From testing both RLL types on my B&B way back, I discoverd that the  
extra sector version was faster; it didn't have to step the head as much.

-- 
L. Curtis Boyle