27 Nov
2010
27 Nov
'10
8:18 p.m.
----- 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:
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.
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