Re: tape baking

[Mark J. Blair via cctalk]

> On Jul 6, 2017, at 11:20 AM, Chuck Guzis via cctalk <cctalk@classiccmp.org> 
> wrote:
> 
> On 07/06/2017 11:09 AM, Mark J. Blair via cctalk wrote:
> 
>> Did you apply it to the whole tape prior to reading it, or did you apply it 
>> in place on the tape drive while reading the tape?
> 
> The whole tape--I ran my tape cleaner at low speed and used a strip of
> 1/2" thick synthetic felt glued to a large PVC pipe fitting as the
> applicator.  Needless to mention, it was on the supply side of the
> cleaner, or else the tape wouldn't have made it through.   The
> lubrication lasted for two reads of the tape.


I don't have a tape cleaner. Maybe I should make one. In particular, for those 
damned TK50 tapes!

> 
> I think I did a moldy tape of Noel's last year this way also and got the
> whole thing.
> 
>> Are they online anywhere? I wouldn't mind taking a look at them.
> 
> No, but I can put a copy up on my Box account.  Do you want the original
> EBCDIC .tap image or the ASCII-translated files?


I would enjoy seeing the ASCII translated files. I don't have any experience 
dealing with EBCDIC-era stuff yet.


-- 
Mark J. Blair, NF6X <n...@nf6x.net>
http://www.nf6x.net/

Re: tape baking

[Mark J. Blair via cctalk]

> On Jul 6, 2017, at 10:59 AM, Chuck Guzis via cctalk  
> wrote:
> 
> That's what I do when baking doesn't do the trick; e.g. binder
> bleed-through.  But, as Al says, don't overdo it.  I used a thick felt
> wiper to deposit a thin film on a 2400' reel of tape.  I added more to
> the wiper about halfway through.  Perhaps 5 ml or less for the whole tape.

Did you apply it to the whole tape prior to reading it, or did you apply it in 
place on the tape drive while reading the tape?

> 
> It worked--I retrieved a tape of line printer art from Princeton quite
> successfully.  Oddly, nobody was interested in a copy of the files.

Are they online anywhere? I wouldn't mind taking a look at them.



-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: tape baking

[Mark J. Blair via cctalk]

> On Jul 6, 2017, at 09:55, Al Kossow via cctalk <cctalk@classiccmp.org> wrote:
> 
> 
> 
> On 7/6/17 9:47 AM, Mark J. Blair via cctalk wrote:
>> Maybe I could make a machine to allow me to unspool a TK50 tape while wiping 
>> on cyclomethicone and then re-spool it, perhaps by hacking up a drive 
>> mechanism.
>> 
> 
> It evaporates too quickly.
> I have also seen it dissolve binder if you use too much.

Can the cyclomethicone be used to help address sticky shed on a tape? If it 
evaporates too quickly to apply it to an entire tape before reading, then 
perhaps by placing a wiper in the tape path to apply it during reading would 
work?

-- 
Mark J. Blair, NF6X <n...@nf6x.net>
http://www.nf6x.net/

Re: tape baking

[Mark J. Blair via cctalk]

> On Jul 4, 2017, at 08:16, Al Kossow via cctalk  wrote:
> 
> The 'out-gassed material' is water, which has been absorbed
> by the binder, which is hydroscopic.

Has anybody experimented with drying media in a vacuum chamber at room 
temperature?

My abortive attempt to play with an old TK50 tape in a TZ30 drive was a 
disaster of sticking, oxide shedding, and manual unloading/respooling of a tape 
that the drive could no longer handle. I had not tried baking the tape.

I do plan to make some sort of media baking setup when that project bubbles 
back to the top of the list. I wonder if pulling vacuum on a tape for a while 
might also have the desired effect? I have a bottle of cyclomethicone on order. 
I wonder if I might need to make some sort of reeling machine to apply it to 
tapes? The TK50 tapes are particularly resistant to manual manipulation. Maybe 
I could make a machine to allow me to unspool a TK50 tape while wiping on 
cyclomethicone and then re-spool it, perhaps by hacking up a drive mechanism.

-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: Fixing flakey floppies

[Mark J. Blair via cctalk]

I have also encountered many drives in which the grease inside the hub spindle 
and/or hub clamp bearings had dried out. When I am cleaning up a new-to-me old 
floppy drives, I check all of the ball bearings in the spindle and hub clamp to 
make sure that they spin freely. If they drag noticeably, then I take them out 
and work some very light oil into them. So far, I have been able to get all of 
them spinning freely without needing to replace any of them.


-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: Directory of old computer collectors

[Mark J. Blair via cctalk]

> On May 22, 2017, at 1:19 PM, steven stengel via cctalk 
>  wrote:
> 
> Please let me know if I may, or may not, place your information on the public 
> webpage.

As long as it's just city and email address, I don't mind being on the list. My 
email address and city are already all over the place, anyway. And while I'm 
here, thanks again for the items which you have helped move to my collection, 
and in one case through my collection to an even better home.

-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: DCC-116 E / DATA GENERAL NOVA 2/10 / Nixdorf 620 - Restoring and restarting

[Mark J. Blair via cctalk]

I do not have anything useful to say, but I liked your pictures and video. 
Congratulations on a successful first boot!

-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: Introducing the UUCP/Usenet Project

[Mark J. Blair via cctalk]

For a year or two in college, I was running UUCP on my Amiga 1000. I had it 
dialing into the SPARCstation IPC on the computer support desk at UCI. Gack, I 
still remember the pain of hacking the sendmail.cf without the benefit of the 
later m4 macros, in order to get the mail forwarding working.

-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: FTGH (you come get): VAXstation 100 terminals

[Mark J. Blair via cctalk]

> On Mar 6, 2017, at 6:34 PM, Jason T via cctalk  wrote:
> 
> Before getting rid of them all, maybe you (or someone on the list who
> receives one) could consider taking some photos for the Terminals
> Wiki.  I don't believe it has an entry there yet:

If I get them, there will (eventually) be pictures, and maybe even a YouTube 
video. The very limited information that seems to be available online makes 
them even more interesting to me!

Hmm, I would probably need to rig a Unibus expansion chassis for my VAX-11/730, 
since its card cage is full.

-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: FTGH (you come get): VAXstation 100 terminals

[Mark J. Blair via cctalk]

Ugh, this leaves me feeling so conflicted. One or more of these rigs sounds so 
tempting, but both my house and my 11/730's Unibus cage are full. Do I stash 
one in one of my sea containers in the hope that someday find time to let it 
timeshare a desk in my house, and also find a place to plug it in? Or do I do 
the sane thing, and pretend I never saw this posting? :)

-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: Magtape write rings [Was: Re: Full immersion emulation]

[Mark J. Blair via cctalk]

That all makes perfect sense now. Thanks!

-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Magtape write rings [Was: Re: Full immersion emulation]

[Mark J. Blair via cctalk]

> On Mar 5, 2017, at 09:49, Chuck Guzis via cctalk  
> wrote:
> 
> I don't recall many who used those yellow rings for their intended
> purpose.  It was just too easy to forget to remove one.  You mounted
> tapes without and reached around the back of the reel with a punch card
> and tripped the "finger" that detected the ring.

So, was the write enable state latched at some point in the loading cycle on 
those drives? That surprises me, because I would have expected the write enable 
sensor to interrupt write current as combinatorial function on the drive, 
and/or pass sensor status up to the formatter a combinatorial signal.


-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: Full immersion emulation

[Mark J. Blair via cctalk]

> On Mar 4, 2017, at 21:42, Jon Elson  wrote:
> 
> Oh, get a TU78, for sure!

I would settle for either!

-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: Full immersion emulation

[Mark J. Blair via cctalk]

> On Mar 4, 2017, at 17:09, Jon Elson  wrote:
> 
> Hmmm, on our TU77, the vacuum pump was not that audible, but then it was in a 
> room with a LOT of noise.

My memory might be faulty, since it has been about 25 years since I've heard a 
TU77. I don't suppose anybody near southern California has an extra one I might 
adopt? :)


-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: Full immersion emulation

[Mark J. Blair via cctalk]

> On Mar 4, 2017, at 1:22 PM, Jon Elson <el...@pico-systems.com> wrote:
> 
> On 03/04/2017 03:13 PM, Mark J. Blair via cctalk wrote:
>> For some reason, I fondly remember the scream of a DEC TU77 drive, and would 
>> like to have one in my collection. Clearly, I must be somewhat touched in 
>> the head. :) 
> Scream?  Or buzz?  We had a TU77, and when we ran backups, it made a loud 
> buzzing as it was doing start/stop about as fast as it could go.  Or, are you 
> referring to the whine as it went into rewind?

I mostly remember the shop-vacuum-like whine of the vacuum pump, and the 
fluttery thwack of the tape loops forming on load-up. The other tape motion 
sounds didn't stick in my memory so much. I do remember the buzzy grind of the 
capstan motors on the C240's tape drive; I don't recall whether that drive's 
OEM was Fujitsu or Hitachi, but I found it quite enjoying to watch as an 
engineering student.


-- 
Mark J. Blair, NF6X <n...@nf6x.net>
http://www.nf6x.net/

Re: Full immersion emulation

[Mark J. Blair via cctalk]

> On Mar 1, 2017, at 11:39 AM, Chuck Guzis via cctalk  
> wrote:
> 
> There are certain experiences that I would not rather relive for the
> sake of nostalgia.  Computer room noise would be right up there with
> kidney stones and root canals.

Having experienced both 1980s computer rooms and passing kidney stones, I would 
like to offer my opinion that visiting a noisy computer room is something quite 
fun to do at least once, while one could skip the experience of passing kidney 
stones entirely without any regrets.

In my experience, visiting a computer room was enjoyable, while hanging out 
there for a full shift got rather tedious. The computer room I worked in at UCI 
had an enclosed, glassed-in office for the computer operator that provided a 
nice retreat from the noise between tape swaps and printer handling tasks. I 
also fondly remember that warm spot behind the Convex C240 power supply cabinet 
exhausts, which was the warmest spot in the room when the main Computer Science 
building AC kicked in at 6AM and the computer room temperature plummeted for a 
while.

For some reason, I fondly remember the scream of a DEC TU77 drive, and would 
like to have one in my collection. Clearly, I must be somewhat touched in the 
head. :)

-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/