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Where to find mini cassettes ??

PostPosted: Fri Feb 08, 2013 5:44 pm
by moulinaie
Hi,

I am new here, cheers to all.

I have a HP 82161A connected to my HP41CX and can't use it... I think the problem comes from the Cassette:

drive is ON, I switch ON the calculator, I type:

XEQ NEWM 020

The works starts on the drive (one pass, rewind, second pass, rewind and try to read something three times) and the calculator displays:

MEDM ERR

Where can, reliable cassette, be found nowdays???

Thanks a lot

Re: Where to find mini cassettes ??

PostPosted: Fri Feb 08, 2013 7:47 pm
by Garth
Welcome.

Sometimes the tapes show up on eBay, but they're not cheap.

Before doing any drastic measures, make sure the pad that presses the tape up against the head is ok. If you replace it and it still doesn't work, I wonder if reformatting your tape (with the NEWM command) would work. It seems worth a try since you can't read the tape anyway. There's a post about refurbishing the cassettes (actually putting new tape in them), here, and one about the mirrors here.

After someone said the tapes deteriorate over the decades, I had an occasion last year to find out mine all worked fine. I have an HP-71 with 177K of RAM, enough that I could just keep everything I wanted in the machine all the time. (That's basically true of my 41cx with double extended memory module also.) One of the 71's memory modules went down, apparently not from any hardware problem but some kind of configuration problem, and I had to re-load a lot of files. I had not even turned my tape drive on in many years, and had to use clip leads to connect a separate 5V power supply in place of the no-good rechargeable battery pack. To my delight, it worked perfectly, tape after tape.

I like to keep a printed copy of everything on the 41 (and not on thermal print paper that fades!). It's not practical of course on something with megabytes-long files, but on the 41, if worst comes to worst and you have to key it back in, it's short enough that it's not out of the question, and it's much faster than having to re-write things from scratch.

Re: Where to find mini cassettes ??

PostPosted: Sat Feb 09, 2013 8:36 am
by moulinaie
Hello,

Thanks to your different ideas I had a look at the little soft pad behind the tape that maintains the tape in contact with the magnetif head of the drive. (I hope you understand what I mean with my approximative english!).

The pad had two problems: it had slided to one side and the metal behind it seemed curved in the wrong direction.

So, I pulled the pad off, (half remained on the metal and half came) put some glue, a layer of paper, some glue again and the pad on it.

Then, with a little hook, I gently pulled the metal towards the outside to have it straight and not curved.

AND IT WORKS !!!

NEWM 020 -> OK
Then I tried a
WRTA to save all the memory -> OK again
and a dos-like
DIR
That said I have one file:
BACKUP WA

I don't know if what I did is reliable in a long term. So, I'm still interested if someone has some cassettes to sell.
New ones, or "not-so-old" ones...

Thanks a lot!

Guillaume.

"B side"..!!!

PostPosted: Sat Feb 09, 2013 10:07 am
by moulinaie
Hi again,

For my second cassette, the pad repair was not enough.
Looking at the tape, it seemed a bit damaged on one border.
I had the idea of turning the cassette upside down to use the other side (as an old audio tape).
The problem comes from the "snick" (I hope you understand) that prevent the cassette from being used in the wrong side.

So, I made a second snick... put the cassette in the drive on the wrong side... and it WORKS !!

I didn't do it very correctly as I removed too much plastic and that the inside of the cassette is now "open" to external air and dust.
Next time I'll take care of this, but this was my first attempt..!

Guillaume.

Re: Where to find mini cassettes ??

PostPosted: Sat Jun 29, 2013 12:28 pm
by aydin1954
I am also in the same bind of finding cassettes and repairing old ones.
I was lucky to find a lot of 4 on eBay, the guy wanted $50 each but I talked it down to $30 each if I bought all. Now waiting for them to arrive.

Then I have 4 and the problem is like it is said on other forums with the the pressure pad. This consists of a layer of felt on top of a foam pad, and the foam decays with time. One solution is to find one that is in good state open the cassette (by carefully prying in the two holes with a small screwdriver until it pops with white label up to avoid pieces falling out) and exchange the pressure pad. I did it on two and it brought them back to live. So I will then recover the content to the new ones I am getting just to be safe.

Then I found this article that can be of use : http://www.hpmuseum.org/guest/duell/rep82176.pdf

Re: Where to find mini cassettes ??

PostPosted: Tue Nov 29, 2016 12:11 am
by bdenley
I have found cassettes that are compatible with my cassette drive: Braemar CMC80. They look like they were made by the same manufacturer. I just bought 20.

Brian