On 8/10/2021 10:30 PM, Jay Jaeger via cctech wrote:
On 7/29/2021 1:22 PM, Mark Huffstutter via cctech wrote:
Yes, I sadly, learned that important lesson years ago, after finding My
"Original" Original PC DOS diskette set pretty much destroyed, left in
The folders in storage for too long.....
-----Original Message-----
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Al
Kossow via cctalk
Sent: Thursday, July 29, 2021 10:15 AM
To: cct...@classiccmp.org
Subject: Re: IBM PC diagnostics disks
On 7/29/21 10:08 AM, Mark Huffstutter via cctalk wrote:
Hi Richard,
I could use them if they are still available, I
have the very nice binder manual for them, minus the disks!
Don't store diskettes in vinyl sleeves.
The plasticiser leaches out of the vinyl onto the surface of the
diskettes.
Interesting. The IBM ones that I have had in the clear 5 x 8.5 vinyl
sleeves were in their paper-like material sleeves inside the vinyl. They
have been mostly just fine - just read them in this past week.
On the other hand maybe 10% or so of my 3B2 floppies that were similarly
stored, but in a somewhat different form of vinyl had more sector
errors. Fortunately I copied some of them (the most critical ones) some
time ago, and those were stored separately, so I expect those will be
fine, but I haven't yet read them in.
JRJ
Correction: Out of 49 AT&T floppies that were in their paper envelopes
inside vinyl exactly ONE turned out to actually be bad - and it had been
bad many years ago (1997) when I got them. So, to date I have not
experienced any issues with vinyl holders - so long as the floppy is in
its paper sleeve, at least.
The problem I actually discovered this week that I was not reading the
3B2 floppies on a 96 TPI drive (they are 512 byte sectors, 80 tracks,
two sides, 9 sectors "quad" density.) Once I figured that out, all but
the one read just fine. On the other hand, several copies I made on a
PC floppy drive (I think) back when were mostly bad (either that, or I
made them on the 3B2, but used HD media, perhaps).
One final note: why do I re-image stuff using different techniques?
Well, here is a case in point. The images that (I believe) I had made
of these floppies in 1997 - I think using dd on the 3b2 itself to files
on the hard disk, and then transferred using zmodem to my PC - were all
ONE TRACK SHORT. Now, there is a pretty good chance that that last
track on most of those floppies didn't have any real data - but one
never knows. I did verify that the first 79 tracks of those images, and
those I made the past couple of days were the same.
Using my new greaseweazle I have verified that images I made of PC
floppies of various sorts (160, 360, 720, 1.2M (including RT/PC),
1.44M), RX50 were all just fine. Only the 3B2 images were off.
JRJ
