Re: BA123 Side panels and Stuck TK50

[Douglas Taylor]

On 8/30/2016 4:54 PM, shad wrote:

Hello,


The same cabinet has a TK50 and I foolishly put a cartridge into it and
now it won't come out.  It is called being 'stuck'.  How do proceed to
get this TK50 cartridge out?


Error 'stuck' means that the tape has been "glued" to the head because 
of the effect

of the tape binder being converted to adhesive due to age and moisture.
You can remove the cartridge in this way:
- pull the drive out of the machine
- carefully unscrew the metal cover over the internal reel and the 
head to expose it
- slowly insert a paper sheet between the tape and the head, in the 
same direction of the tape, to detach it without damage
- slowly rotate the front motor (from bottom side) in way to rewind 
all the tape from the back reel to the cartridge reel

- detach the tape leader if necessary
- now keep the electromagnetic cartridge unlock mechanism pressed, and 
remove the cartridge from the drive


A tape in this condition of striction is probably unusable anyway, 
unless you back it up a little in an oven,

but even so it could be readable just for a couple of hours


I removed the drive from the MicroVax and took off the metal cover on 
the TK50.  There was about 1/2 inch of tape on the takeup reel and it 
moved freely.
The documentation on bitsavers told me what I should have known in the 
first place.  The Green and Red lights indicate the health of the drive.
When the drive first powers on the red light should be on during a brief 
diagnostic test, then the red light should go out and the green light 
should come on indicating that the drive has passed internal tests and 
is ready.  My TK50 never lights the green light and before I cleaned it 
out the red light would blink indicating an internal fault.

Geez I hate these things.

The Bitsavers doc had a section for bench service and interpreting error 
codes, does anyone know how to get these codes?   Is there a PDP11 or 
VAX diagnostic that reports these codes?  Can you get at them from ODT 
or the VAX console?


I still would like to rewind the tape and remove the cartridge, but it 
looks like a difficult task to rewind by hand.






Also, the TQK50 controller never saw the drive and I was wondering if
the PROM's (after 30 years) on the board lose their data?


Well, I never seen an UV-EPROM loose it's data, unless the erase 
window cover is missing and the memory exposed to the sun light.


Andrea

RE: BA123 Side panels and Stuck TK50

[Rob Jarratt]

> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of jim
> stephens
> Sent: 31 August 2016 04:08
> To: r...@jarratt.me.uk; General Discussion: On-Topic and Off-Topic Posts
> <cctalk@classiccmp.org>
> Subject: Re: BA123 Side panels and Stuck TK50
> 
> I've bought a pile of drives recently, and may have one that you can
> scavenge.  However I think mine may be TK-70's though.
> 

Actually mine was a TK70, I *think* the leader is the same in both drives in
any case. If you have a spare that would be nice, but I think I may have a
spare tucked away somewhere anyway. My query was really about whether it was
possible to repair the tear, because one for the tip is not completely torn
off.

Regards

Rob

Re: BA123 Side panels and Stuck TK50

[Ethan Dicks]

On Tue, Aug 30, 2016 at 6:32 PM, Rob Jarratt
 wrote:
> I think you are referring to me. The leader I was talking about was the one
> *inside the drive* that hooks the tape in the cartridge. I may have used the
> wrong term, if so sorry about that.

I saw your posts and saw that you were referring to a torn barb, so I
read that as the part that does fail and was replaced from time to
time with a fresh spare.

So far, I don't think anyone has come up with a good repair or
replacement other than "use a new one"... I think it might be
possible, now, to inexpensively laser-cut one from a suitable material
- I was thinking PET film of the appropriate weight and stiffness.
Someone mentioned trying 35mm acetate unsuccessfully.

Step 1: CAD up a good leader...
Step 2: experiment with different materials...
Step 3: Profit!

-ethan

RE: BA123 Side panels and Stuck TK50

[Rob Jarratt]

> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of jim
> stephens
> Sent: 30 August 2016 23:19
> To: General Discussion: On-Topic and Off-Topic Posts
> <cctalk@classiccmp.org>
> Subject: Re: BA123 Side panels and Stuck TK50
> 
> 
> 
> On 8/30/2016 1:54 PM, shad wrote:
> >
> > A tape in this condition of striction is probably unusable anyway,
> > unless you back it up a little in an oven, but even so it could be
> > readable just for a couple of hours
> I wonder if the header could be cut off and used for the other guy's
thread,
> who has the broken leader. 

I think you are referring to me. The leader I was talking about was the one
*inside the drive* that hooks the tape in the cartridge. I may have used the
wrong term, if so sorry about that.

> That wouldn't involve the magnetic media being
> involved, and might fix his tape cartridge.  I think someone suggested
> sacrificing a cartridge, this would be better than a possibly good one as
a
> source for the leader.
> 

So sacrificing a cartridge wouldn't help in my case

Regards

Rob

RE: BA123 Side panels and Stuck TK50

[Rob Jarratt]

> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Douglas
> Taylor
> Sent: 30 August 2016 17:52
> To: General Discussion: On-Topic and Off-Topic Posts
> 
> Subject: BA123 Side panels and Stuck TK50
> 
> This is real trivia but I have a BA123 cabinet (MicroVax II) and there a 
> screws
> that hold the side panels in place, and mine are missing.  Does anyone know
> the type of screw I should go look for at the hardware store?
> 

The panels on mine just clip on, I don’t think there are any screws. The panels 
don't stay on very well on mine :-(


> The same cabinet has a TK50 and I foolishly put a cartridge into it and now it
> won't come out.  It is called being 'stuck'.  How do proceed to get this TK50
> cartridge out?

You will have to remove the drive and take the cover off the inner reel. It 
could be that the tape has become stuck to the heads and you just need to free 
it.

> 
> Also, the TQK50 controller never saw the drive and I was wondering if the
> PROM's (after 30 years) on the board lose their data?

Not sure, I have never had this problem.

Regards

Rob

Re: BA123 Side panels and Stuck TK50

[jim stephens]

On 8/30/2016 1:54 PM, shad wrote:


A tape in this condition of striction is probably unusable anyway, 
unless you back it up a little in an oven,

but even so it could be readable just for a couple of hours
I wonder if the header could be cut off and used for the other guy's 
thread, who has the broken leader.  That wouldn't involve the magnetic 
media being involved, and might fix his tape cartridge.  I think someone 
suggested sacrificing a cartridge, this would be better than a possibly 
good one as a source for the leader.


thanks
jim

Re: BA123 Side panels and Stuck TK50

[shadoooo]

Hello,


The same cabinet has a TK50 and I foolishly put a cartridge into it and
now it won't come out.  It is called being 'stuck'.  How do proceed to
get this TK50 cartridge out?


Error 'stuck' means that the tape has been "glued" to the head because of the 
effect
of the tape binder being converted to adhesive due to age and moisture.
You can remove the cartridge in this way:
- pull the drive out of the machine
- carefully unscrew the metal cover over the internal reel and the head to 
expose it
- slowly insert a paper sheet between the tape and the head, in the same 
direction of the tape, to detach it without damage
- slowly rotate the front motor (from bottom side) in way to rewind all the 
tape from the back reel to the cartridge reel
- detach the tape leader if necessary
- now keep the electromagnetic cartridge unlock mechanism pressed, and remove 
the cartridge from the drive

A tape in this condition of striction is probably unusable anyway, unless you 
back it up a little in an oven,
but even so it could be readable just for a couple of hours



Also, the TQK50 controller never saw the drive and I was wondering if
the PROM's (after 30 years) on the board lose their data?


Well, I never seen an UV-EPROM loose it's data, unless the erase window cover 
is missing and the memory exposed to the sun light.

Andrea