OT: Quote of the day

Doug Franklin jehosephat at mindspring.com
Sat Oct 3 10:51:22 EDT 2009

Joseph McAllister wrote:
> OMG> In the inter-sector gap? In my day we never even considered the 
> ISG. I do remember discussions about being able to buffer enough read to 
> do a linear read for small files.

I misspoke slightly ... there was a day when the fastest *PCs* *had* 
*disk* *interface* *hardware* *that* couldn't deal with a sector in the 
ISG, so the disks were interleaved such that physically adjacent sectors 
had non-sequential sector numbers.  A 1:3 ratio was common, so the 
sectors would be numbered 147258369 for example instead of 123456789.

> Giving it some thought just now, I guess the 7200rpm hard drives, even 
> 10,000rpm drives, read sequentially as well.

They do now. :-)  I'm referring to the age of the PC/XT and PC/AT (early 
to mid 1980s) and before.  Specifically the era of ST-506 and MFM as the 
most common disk interface standards.  Probably 3600rpm or maybe 5400rpm 
drives, but I don't really remember.

DougF (KG4LMZ)

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