19 May
2015
19 May
'15
12:23 a.m.
Johnny Billquist <bqt at update.uu.se> wrote:
The TK50 normally do not gum up. There are two
problems with them, and
those problems have been around since day 1.
The first one is that the heads get dirty. Cleaning with isopropanol or
similar with a lint-free pad solves that just fine.
The second problem is that the tape pickup gets unhinged. Remove the
covers and then you can fix that easily.
So much for "YMMV": jkunz and I must have had some really bad tapes back
then at the VCFe a couple of years ago. When we tried to read them (in
a TK70, I think - does that make the difference?), they slowed down the
mechanism, produced a squealing sound and stuck to the head to the point
where in some cases the tape (carrier) broke in some cases. We did clean
the head and tape guide parts with IPA several times only to get the
same problem again. I'm sure he can elaborate a bit more about the tapes
and the equipment used but I think I have it mostly correct.
So Long,
Arno
19 May
19 May
3:25 a.m.
On 2015-05-19 09:23, Arno Kletzander wrote:
Johnny Billquist <bqt at update.uu.se> wrote:
Wow. That is definitely YMMV then. I've never seen that happen anywhere,
and I occasionally still work with TK50s. (Even professionally.)
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
The TK50 normally do not gum up. There are two
problems with them, and
those problems have been around since day 1.
The first one is that the heads get dirty. Cleaning with isopropanol or
similar with a lint-free pad solves that just fine.
The second problem is that the tape pickup gets unhinged. Remove the
covers and then you can fix that easily.
So much for "YMMV": jkunz and I must have had some really bad tapes back
then at the VCFe a couple of years ago. When we tried to read them (in
a TK70, I think - does that make the difference?), they slowed down the
mechanism, produced a squealing sound and stuck to the head to the point
where in some cases the tape (carrier) broke in some cases. We did clean
the head and tape guide parts with IPA several times only to get the
same problem again. I'm sure he can elaborate a bit more about the tapes
and the equipment used but I think I have it mostly correct. 
20 May
20 May
12:06 p.m.
Am 19.05.15 um 12:25 schrieb Johnny Billquist:
Wow. That is definitely YMMV then. I've never seen that happen anywhere,
and I occasionally still work with TK50s. (Even professionally.)
It was a TZ30 in a
DEC3000 running NetBSD, IIRC. We tried several TK50
tapes and all of them exhibited the sticky tape problem. And my 9-track
tapes are rotten to the point of uselessness too. They still worked most
of the time about 10 years ago. (In 2001 I installed 2.11BSD on my /73
using a TK50.) The tapes where stored under normal household conditions.
I suppose the time of those tapes is long gone. The only use for them
now is wall decoration. :-(
--
tsch??,
Jochen
12:11 p.m.
On 2015-05-20 21:06, Jochen Kunz wrote:
Am 19.05.15 um 12:25 schrieb Johnny Billquist:
Hmm. There might also be other issues when using a TZ30 as compared to a
TK50 here... I don't even remember how the TZ30 looks inside. There
might be rubber parts in there.
Johnny
Wow. That is definitely YMMV then. I've never seen that happen anywhere,
and I occasionally still work with TK50s. (Even professionally.)
It was a TZ30 in
a DEC3000 running NetBSD, IIRC. We tried several TK50
tapes and all of them exhibited the sticky tape problem. And my 9-track
tapes are rotten to the point of uselessness too. They still worked most
of the time about 10 years ago. (In 2001 I installed 2.11BSD on my /73
using a TK50.) The tapes where stored under normal household conditions.
I suppose the time of those tapes is long gone. The only use for them
now is wall decoration. :-( 
12:36 p.m.
On 5/20/15 12:11 PM, Johnny Billquist wrote:
There might be rubber parts in there.
Nope, I like them better than TK50s, though, because you pop off the two C rings
and the head assembly
lifts up to clean, which is necessary after every tape you try to read.
TK50 tapes stick or gum up at the ends just like QIC carts do. I haven't tried baking
them. Thankfully
there are almost none in the queue right now to read and hopefully it will stay that way.
12:48 p.m.
On 2015-05-20 21:36, Al Kossow wrote:
On 5/20/15 12:11 PM, Johnny Billquist wrote:
I think I have one or two TZ30 somewhere. Maybe I should look more at them.
But the TK50 is really easy to clean. You just remove the 3 screws that
holds the cover plate, and then you just clean the heads where they are.
But yes, you do need to clean the heads a lot on those drives. I believe
I mentioned that in my original reply. :-)
There might be rubber parts in there.
Nope, I like them better than TK50s, though, because you pop off the two
C rings and the head assembly
lifts up to clean, which is necessary after every tape you try to read. TK50 tapes stick or gum up at the ends just like QIC
carts do. I haven't
tried baking them. Thankfully
there are almost none in the queue right now to read and hopefully it
will stay that way.
Interesting. I haven't seen that. And they construction is totally
different from QIC tapes as well, unless my memory is failing me even more.
Johnny
1:35 p.m.
In case someone hasn't mentioned baking the tapes apparently an hour at 50
degc works wonders
On 20 May 2015 20:48, "Johnny Billquist" <bqt at update.uu.se> wrote:
On 2015-05-20 21:36, Al Kossow wrote:
On 5/20/15 12:11 PM, Johnny Billquist wrote:
I think I have one or two TZ30 somewhere. Maybe I should look more at them.
But the TK50 is really easy to clean. You just remove the 3 screws that
holds the cover plate, and then you just clean the heads where they are.
But yes, you do need to clean the heads a lot on those drives. I believe I
mentioned that in my original reply. :-)
TK50 tapes stick or gum up at the ends just like QIC carts do. I haven't
There might be rubber parts in there.
Nope, I like them better than TK50s, though, because you pop off the two
C rings
and the head assembly
lifts up to clean, which is necessary after every tape you try to read.
tried baking them. Thankfully
there are almost none in the queue right now to read and hopefully it
will stay that way.
Interesting. I haven't seen that. And they construction is totally
different from QIC tapes as well, unless my memory is failing me even more.
Johnny
1:41 p.m.
On 2015-05-20 21:06, Jochen Kunz wrote:
It largely depends on storage conditions. I
recently read some of my
old backup tapes from the mid 1980's with no problem. The drive did a
little bit of backing up and retrying, but I got 100% data recovery.
I've had some other tapes that were not stored in proper conditions
where all the oxide fell off and collected on the tape heads. (I'm
referring to 9 track tapes, here.)
Jon
And my 9-track
tapes are rotten to the point of uselessness too. They still worked most
of the time about 10 years ago.
22 May
22 May
9:24 p.m.
On 05/21/2015 01:19 AM, Jochen Kunz wrote:
Am 20.05.15 um 22:41 schrieb Jon Elson:
The
"bad" conditions I mentioned were attics and damp
basements. Any normal home environment should be quite good
for tape storage.
Jon
It largely depends on storage conditions.
Sorry I can not afford a climate controlled cabinet. The tapes where
stored in my "machine room", i.e. a normal bedroom in my flat. 
23 May
23 May
10:04 a.m.
I got my TK50 drive from eBay. Boy, that tape feeding mechanism sure looks screwy! I'd
like to get a modern DLT drive for my modern computer backups (after I sell a few more
kidneys, that is), but I'm still a bit suspicious of their similar (identical?) tape
feeding scheme. All of my bad experience with things like QIC, DAT, etc. had led me to be
very suspicious of tape systems other than 1/2" open reel.
--
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/
10:11 a.m.
On 2015-05-23 19:04, Mark J. Blair wrote:
I got my TK50 drive from eBay. Boy, that tape feeding
mechanism sure looks screwy! I'd like to get a modern DLT drive for my modern computer
backups (after I sell a few more kidneys, that is), but I'm still a bit suspicious of
their similar (identical?) tape feeding scheme. All of my bad experience with things like
QIC, DAT, etc. had led me to be very suspicious of tape systems other than 1/2" open
reel.
It's not that bad. The TK50 sometimes get the pickup unhooked from the
arm, but once you realize how it works, it's really easy to fix it when
that happens. Apart from that, the tape movement works fine. When the
pickup lead gets unhooked you cannot even put a cartridge in.
The other problem (as I mentioned) is dirty heads. That will cause the
tape to fail to actually load, since the heads will move up and down
trying to find track 1 and eventually give up. At which point you see it
flashing quickly red on the load button.
The third issue is a general problem with just one button expected to do
all functions, and just one lamp in the button indicating issues. The
drive can just get confused, and you cannot tell what it is doing, and
it is not possible to unload the tape. Very annoying. You can usually
solve that by power cycling the thing.
This all worked better in the TK70. I guess they had to figure things
out by trial and error. :-)
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
12:40 p.m.
On 05/23/2015 10:04, Mark J. Blair wrote:
I'd like to get a modern DLT drive for my modern
computer backups
The current hotness is LTO (Linear Tape Open), I think LTO-5 gives you
3.0TB assuming 2:1 compression - and LTO-6 is probably the current flavor.
(after I sell a few more kidneys, that is)
Careful hunting on eBay can produce LTO-4 capabilities (0.8/1.6TB) for
not too many vital organs. Just make sure you've got a fibre channel or
SAS interface to talk to it.
... but I'm still a bit suspicious of their
similar (identical?) tape feeding scheme. All of my bad experience with things like QIC,
DAT, etc. had led me to be very suspicious of tape systems other than 1/2" open reel.
If you take a careful look at the TK and DLT mechanisms, I think you'll
see that they're an awful lot closer to an open reel design than any of
the cartridge designs (QIC, DAT, 8mm, AIT, etc).
I'd never say they're perfect because that would immediately render all
my backups on any media unreadable. But if I have to trust a tape
mechanism, I'll stick with the TK-DLT-LTO line.
--S.
1:52 p.m.
On May 23, 2015, at 12:40, Steven M Jones
<classiccmp at crash.com> wrote:
Right. Me being the smart, forward-thinking guy I'm not, I bought a nice, sexy Mac
Pro, and then a nice little mid-range QNAP NAS that has neither fibre channel nor SAS
capabilities before I determined that I really could use proper tape backup and started
investigating what interfaces are suitable for that. There's one very nice-looking
LTO-6 drive with a Thunderbolt interface that will plug into my Mac Pro. Lots of kidneys
for that one!
(after I sell a few more kidneys, that is)
Careful hunting on eBay can produce LTO-4 capabilities (0.8/1.6TB) for not too many vital
organs. Just make sure you've got a fibre channel or SAS interface to talk to it.
... but I'm still a bit suspicious of their
similar (identical?) tape feeding scheme. All of my bad experience with things like QIC,
DAT, etc. had led me to be very suspicious of tape systems other than 1/2" open reel.
If you take a careful look at the TK and DLT mechanisms, I think you'll see that
they're an awful lot closer to an open reel design than any of the cartridge designs
(QIC, DAT, 8mm, AIT, etc).
I'd never say they're perfect because that would immediately render all my
backups on any media unreadable. But if I have to trust a tape mechanism, I'll stick
with the TK-DLT-LTO line.
20 May
20 May
11:22 p.m.
Am 20.05.15 um 21:11 schrieb Johnny Billquist:
Hmm. There might also be other issues when using a
TZ30 as compared to a
TK50 here... I don't even remember how the TZ30 looks inside. There
might be rubber parts in there.
No rubber. The tapes got stuck to the read-/write
head.
--
tsch??,
Jochen
3501
days inactive
3505
days old
14 comments
9 participants
participants (9)
-
aek＠bitsavers.org -
Arno_1983＠gmx.de -
bqt＠update.uu.se -
classiccmp＠crash.com -
elson＠pico-systems.com -
jkunz＠unixag-kl.fh-kl.de -
jonathanelson＠email.wustl.edu -
mark＠wickensonline.co.uk -
nf6x＠nf6x.net