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HP 67 magnetic card not working
12-06-2019, 03:55 AM
Post: #1
HP 67 magnetic card not working
I recently bought the HP 67 Stat Pac, which was looking very good as I was hoping to do the Student's t-test, and realized that at least one of the cards is not working; the t-statistic card (sigh). Side 2 seems to read correctly but not side 1, so it is in fairly good shape and perhaps just slightly "off". I suppose I could type it in by hand using the book, but is there a way to "revive" old and worn magnetic cards?
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12-06-2019, 05:31 AM
Post: #2
RE: HP 67 magnetic card not working
(12-06-2019 03:55 AM)Trond Wrote:  I recently bought the HP 67 Stat Pac, which was looking very good as I was hoping to do the Student's t-test, and realized that at least one of the cards is not working; the t-statistic card (sigh). Side 2 seems to read correctly but not side 1, so it is in fairly good shape and perhaps just slightly "off". I suppose I could type it in by hand using the book, but is there a way to "revive" old and worn magnetic cards?

You would have to add some stiff material to the card where it was cut. I think there is info in the Forum somewhere.

Another option, if you feel confident, is to short the Write Protect Switch connector pin on the CPU board to ground.

Counting from right to left looking down at the CPU board with pins at bottom, WPS is pin 15, ground is on pins 27 and 28 (the two most left pins).

This will override the write protect mechanism and you can re-write a write protected card.

cheers

Tony
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12-06-2019, 08:34 AM
Post: #3
RE: HP 67 magnetic card not working
Here's a recent thread about Disabling HP65/67 card reader write protect.

— Ian Abbott
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12-06-2019, 11:46 AM
Post: #4
RE: HP 67 magnetic card not working
I use a surplus magnetic card cut to this configuration
   
this combined vertical/diagonal cut facilitates an extremely reliable 'overwrite' process on write-protected (corner clipped) magnetic cards. I had/have 100% success using same.

BEST!
SlideRule
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12-06-2019, 04:35 PM
Post: #5
RE: HP 67 magnetic card not working
I recall from an earlier thread on this subject that someone recommended using a Staedtler Mars plastic eraser to gently clean the magnetic side of the card. It was used to revive a card that would not record, so perhaps it will work for your case of faulty readback.

Who decides?
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12-07-2019, 05:17 AM
Post: #6
RE: HP 67 magnetic card not working
(12-06-2019 04:35 PM)mfleming Wrote:  I recall from an earlier thread on this subject that someone recommended using a Staedtler Mars plastic eraser to gently clean the magnetic side of the card. It was used to revive a card that would not record, so perhaps it will work for your case of faulty readback.

Interesting! I'll try this.
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12-07-2019, 05:40 AM
Post: #7
RE: HP 67 magnetic card not working
No luck Sad The eraser did not improve things. I tried rubbing a little, then a lot, but with the same result. I guess I just have to type the program.
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12-07-2019, 08:06 AM
Post: #8
RE: HP 67 magnetic card not working
IIRC you can read side 2 and delete the empty steps that would be covered by side 1. Then type side 1. So you save to type side 2.
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12-07-2019, 09:15 AM
Post: #9
RE: HP 67 magnetic card not working
I dealt with the same issue a while ago when one of the cards in the Standard Pac that came with my HP-67 turned out to be unreadable. The card looked clean and undamaged, and I was able to restore it using the trick mentioned earlier using a card with a bit cut off to fool the write-protect switch.

In addition to what others have said, however, I would like to add two bits of advice: first, it took me several attempts before I had the card back to where it could be read without error, so don't give up too quickly if it doesn't seem to work; and second, after retyping the program, save it to another card first, because you don't want to have to retype the program again and again after every failed attempt. Smile

Good luck!
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12-07-2019, 10:53 AM
Post: #10
RE: HP 67 magnetic card not working
Today took some pictures what I did to restore a card ...
Restored corner can easily be transferred to another card. Adhesive tape only on front side, not the magnetic side.


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12-07-2019, 11:18 AM
Post: #11
RE: HP 67 magnetic card not working
(12-07-2019 09:15 AM)Thomas Okken Wrote:  In addition to what others have said, however, I would like to add two bits of advice: first, it took me several attempts before I had the card back to where it could be read without error, so don't give up too quickly if it doesn't seem to work; and second, after retyping the program, save it to another card first, because you don't want to have to retype the program again and again after every failed attempt. Smile

Does that mean there is no way to non-destructively verify that a card has been recorded correctly?

— Ian Abbott
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12-07-2019, 11:33 AM
Post: #12
RE: HP 67 magnetic card not working
(12-07-2019 11:18 AM)ijabbott Wrote:  Does that mean there is no way to non-destructively verify that a card has been recorded correctly?

Like the VER function in the HP-41? Not that I'm aware of...
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12-07-2019, 08:14 PM
Post: #13
RE: HP 67 magnetic card not working
OK, had to bit the bullet and type it all in. I now have two backups of the t-stat and t-distribution cards Smile At least now all my Stat Pac programs are working. I will let you know if I manage to write it onto the card that came with the pac.
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