SCSI to IDE

Teo Zenios teoz at neo.rr.com
Sat Nov 27 14:18:24 CST 2010


----- Original Message ----- 
From: "Chuck Guzis" <cclist at sydex.com>
To: "General Discussion: On-Topic and Off-Topic Posts" 
<cctalk at classiccmp.org>
Sent: Saturday, November 27, 2010 1:36 PM
Subject: Re: SCSI to IDE


> On 27 Nov 2010 at 9:53, Eric Smith wrote:
>
>
>> PATA drives, and many but not all SCSI drives, are out at the far end
>> of the bathtub curve.  This means that their reliability is now very
>> questionable.  Contrary to popular belief, the MTBF figures in the
>> drive specifications do not give any information about expected
>> longevity of a single drive, so an MTBF of 200,000 hours does not mean
>> that a single drive is expected to last 22.8 years.  The MTBF only
>> applies during the design life of the drive, which is usually five
>> years.  Beyond that, you're living on borrowed time.
>
> I fail to see what you're driving at.  Most of my SCSI drives were
> purchased new between, oh, 15-20 years ago and all have fewer than
> 1000 hours on them.
>
> My situation can scarcely be unique.
>
> --Chuck
>
>

I purchased a case of 20 pcs of 2GB Quantum 50 pin SCSI drives that were 
never used from a guy on craigslist. Some tech school had purchased a bunch 
many years ago to show the students how to set up a SCSI RAID and this box 
was never opened and sat in storage until it was sold for the massive price 
of $15 total. Yea, I get lucky once in a while.

Decent working 50 pin SCSI drives in the 40-500MB range are probably getting 
hard to find these days. Quite a few were in old macs that got recycled by 
now, so if you happen to have one it is probably in a machine. The older 
5.25" drives are harder to find. 500-2GB can still be found if you look hard 
enough. Anything over 2gb should be common, especially in 68 pin. Last few 
years there has been a flood of cheap SCA drives around from decommissioned 
servers in the 9-72GB range.

IDE drives under 500 MB are getting harder to find, but 2GB and larger 
(which is what you would probably use to replace a SCSI drive if you had an 
adapter) will be common for a while. Snooping around a recycler for any 
length of time will show you how common IDE drives are (and how quickly they 
are getting stripped for recycling). I was lucky enough to be able to take a 
huge box of IDE drives home from a scrapper (all under 2GB, mostly under 
200MB), test them for bad sectors and keep the ones I wanted then return the 
discards for a very cheap price (about 50% made the cut out of 50).

What I find to be rare are older laptop hard drives (they seem to not last 
very long), especially the early PS/2 ESDI laptop drives and early Apple 
SCSI laptop drives. Kind of hard making an adapter that will fit in a 
laptop. Even laptop drives under 10GB are not as common as you would think 
(outside of a machine).

 MFM drives can still be found, but they are not that cheap (many people are 
using SCSI or IDE cards in machines that were built with MFM). ESDI not so 
common, same with HVD drives.









More information about the cctech mailing list