[Info-vax] MicroVAX/VMS newbie, couple of questions

[John Santos]

In article <HWxum.63360$la3.27470 at attbi_s22>, wb8tyw at qsl.network 
says...> 
> Tone007 wrote:
> >  > ISTR that all lights flashing on a DLT drive means that there is a
> >> hardware problem.  I think it has something to do with a broken or
> >> misconfigured "leader" that's supposed to hook up with the tape in your
> >> cartridge.
> > 
> > Well, maybe it's just angry because it doesn't have a tape.  I grabbed
> > a blank on eBay, I'll see if the drive wants to do anything with it
> > when it comes.  If not, I guess I'll be sticking with 5.4!
> 
> I would not put a tape in a TK or DLT drive that has lights flashing if 
> it allows it.  It will probably eat it.
> 
> If you are lucky, just the internal leader has come loose and someone 
> will know how to put it back on.
> 
> When I had systems with those type of drives, Field service would 
> replace the leaders once a year as a preventive maintenance.
> 
> The TK70 requires a CompacTape II.  And if it is used, it needs to have 
> been formatted in a TK70 drive, not a TK50, or you will need to be bulk 
> degauss the tape, which will need a very strong degaussing tool.

A TK70 drive will read a TK50 tapes just fine.  It will even try to 
write on it, but that's usually bad news...  I think some pristine 
TK50's might actually work (though there haven't been any in existence 
for at least 20 years.)  Most of the time, it will get part way
through writing and then get unrecoverable errors.  

However, my cheapo Radio Shack bulk eraser did work just fine for
undoing the damage.  (Also, you can write CompacTape II's in a TK50,
which will usually work okay, but renders them unusable in a TK70.
Again the eraser fixes.)

> 
> The TK50 and TK70s are the pre-DLT models.
> 
> It is possible to insert a DLT tape in a TK70 drive if you push hard 
> enough.  If you are careful, it is even possible to remove the tape 
> afterward, but I do not remember if the tape or drive survived it.
> 

Never tried this.  I do know that inserting an 8mm cart upside down in
a TKZ09(??? - a DEC relabeled Exabyte drive that shows up as an "EXABYTE 
EXB-85058HE-0000" on VMS 8.3 Alpha) has "interesting" consequences...
None of the replacement drives Field Service brought here would work
for more than a week until I removed the 3rd terminator from the SCSI 
bus :-(  (The original drive worked fine with an extra terminator in the
middle of the bus for about 6 months before the data destroyer/operator
inserted the cartridge upside-down.  However none of the replacements
were happy with this situation...)


> -John
> wb8tyw at qsl.network
> Personal Opinion Only.

P.S.  Gravity's spell-checker didn't like TKZ and as a correction
it suggested "klutz"...

-- 
John Santos
Evans Griffiths & Hart, Inc.