Magnetic Card Questions
12-05-2020, 09:55 AM
Post: #1
 Kostas Kritsilas Junior Member Posts: 28 Joined: Sep 2020
Magnetic Card Questions
I have a number of magnetic cards (both Hp-65 and HP-67, and I know I can use blank HP-67 cards with the HP-65), and some of them are previously recorded ones by other people. I have a couple of questions, if anybody has the time:

1. The cards have writing on the top (non-magnetic)side. Some are in pencil, some in marker ink. I assume that I can just use a pencil eraser (any pencil eraser, or say, a Staedler white rubber one?) on the ones written in pencil. Is there a preferred method for removing the marker ink, or just don't bother because any solvent used will damage the magnetic side?

2. Because the cards are not write protected (i.e. corners not clipped), I can just overwrite the existing contents, right? Is the magnetic side adversely affected over time, as in no longer retaining magnetism? Can I overwrite previously recorded cards for the HP-67 on the HP-65, or vice versa?

Also, I have the pre-printed Standard packs for the HP-65 and HP-67, so I can use the HP-65 cards on the HP-67, right? Can I then write out the programs on an HP-67 and have the cards in HP-67 format? Or will the HP-67 just write the cards out in HP-65 format again? Idea is to get the programs onto a HP-41CX with its attached card reader.

Kosstas
12-05-2020, 10:46 AM
Post: #2
 Thomas Okken Senior Member Posts: 1,259 Joined: Feb 2014
RE: Magnetic Card Questions
A Staedtler Mars Plastic or similar eraser works great for getting pencil markings off magnetic cards. Probably not so great for marker ink, but I couldn't really say, I've never had to deal with that. Just one word of warning: be sure to hold the cards firmly at both ends while erasing, else it's easy to accidentally bend the cards too far and that can render them unusable.

I've never noticed cards wearing out. Age doesn't seem to hurt them, the ones I have are 40+ years old and work fine in my HP-67. If they have a limit for how often you can overwrite them, I haven't run into it myself.
12-05-2020, 12:57 PM
Post: #3
 AndiGer Senior Member Posts: 333 Joined: Oct 2015
RE: Magnetic Card Questions
Basically you can use the same type of magnetic cards in both machines.
But: Written cards for HP-65 and HP-67/-97 are not interchangable. So - a card written in an HP-65 can't be read by a HP-67/-97 and vice versa. The only compatibility is HP-67/-97 cards in the HP-41 card reader (but there some limits) - and the card reader must be attached when running HP-67/-97 programs.
Respecting the magnetic cards HP-67 and HP-97 are fully compatible.
12-05-2020, 01:16 PM
Post: #4
 Erik-M Junior Member Posts: 37 Joined: Mar 2020
RE: Magnetic Card Questions
On the HP-41 you can set flag 14 to overwrite clipped write protected cards.
After writing the flag is cleared automatically.
Handy in case you want to reuse old cards or update programs.
I never had a card that was unreadable because of age ( all > 30 years) but you can also refresh old cards this way.

I discovered already long time ago that removing ink is impossible without also removing the white layer on he cards. Removing simple pencil text is no problem
12-05-2020, 02:20 PM
Post: #5
 Dave Britten Senior Member Posts: 1,776 Joined: Dec 2013
RE: Magnetic Card Questions
Has anybody tried Bic White-Out correcting tape to "resurface" the cards? I wonder if that would play well with the rollers.

Example:

https://www.amazon.com/BIC-Wite-Out-Corr...B0007L1W0E

And you can overwrite clipped cards on the 65, 67, and 97 by cutting the back end of another card so that it fits flush with the leading end of the clipped card, and feeding it in the back of the card reader about half an inch (i.e. until you hit some resistance). Search for "unprotect card" and you'll probably find a picture explaining it. I had to do this with a few preprogrammed 65 cards that had faded over the years. They rewrote just fine, so the magnetic coating hadn't been damaged, only the information encoded on it.
12-05-2020, 03:03 PM
Post: #6
 Sylvain Cote Senior Member Posts: 1,581 Joined: Dec 2013
RE: Magnetic Card Questions
Over the years, some oxidation appears on the magnetic side of the cards which can cause reading and writing issues.
To remove that oxidation I have made small jigs for small cards (65/67/41) and long ones (71/75).
I put my card in the appropriate one and with a Staedtler Mars Plastic pencil eraser I remove the oxidation (or the pencil marking on the other side)

The jig prevents me from pinching the card which sometimes happened before.
Sylvain
12-06-2020, 01:39 AM
Post: #7
 [kby] Member Posts: 162 Joined: Mar 2014
RE: Magnetic Card Questions
Just to be clear, you can’t read a card written by a -65 on a -67/-97 or vice versa. But you can overwrite the card on either machine, and then it’s now compatible with the overwriting machine. In other other words, a blank card is just that—blank. It has no inherent formatting for a specific machine.

I thought I’ve removed marker and/or cleaned cards with isopropanol.-kby
(12-05-2020 12:57 PM)AndiGer Wrote:  Basically you can use the same type of magnetic cards in both machines.
But: Written cards for HP-65 and HP-67/-97 are not interchangable. So - a card written in an HP-65 can't be read by a HP-67/-97 and vice versa. The only compatibility is HP-67/-97 cards in the HP-41 card reader (but there some limits) - and the card reader must be attached when running HP-67/-97 programs.
Respecting the magnetic cards HP-67 and HP-97 are fully compatible.
12-06-2020, 01:53 AM
Post: #8
 Sukiari Member Posts: 147 Joined: Dec 2014
RE: Magnetic Card Questions
Has anybody explored the possibility of using commonly available magnetic strip on cardboard as a replacement? You can get it in several formulations and it's dirt cheap. There are a finite number of cards and they seem to get more rare and expensive over time.
12-06-2020, 02:58 AM
Post: #9
 Sylvain Cote Senior Member Posts: 1,581 Joined: Dec 2013
RE: Magnetic Card Questions
(12-06-2020 01:53 AM)Sukiari Wrote:  There are a finite number of cards and they seem to get more rare and expensive over time.

Agreed and I would be very surprised to see this package to ever again appear on eBay.
12-06-2020, 03:00 AM
Post: #10
 Dave Britten Senior Member Posts: 1,776 Joined: Dec 2013
RE: Magnetic Card Questions
(12-06-2020 02:58 AM)Sylvain Cote Wrote:
(12-06-2020 01:53 AM)Sukiari Wrote:  There are a finite number of cards and they seem to get more rare and expensive over time.

Agreed and I would be very surprised to see this package to ever again appear on eBay.

Holy cow!!! I didn't realize they sold 1000 packs. I've gradually worked my way up to around 200 blanks, and that should be plenty for my 65 and 97 needs, at least for quite a few years.
12-06-2020, 03:20 AM (This post was last modified: 12-06-2020 03:34 AM by Sylvain Cote.)
Post: #11
 Sylvain Cote Senior Member Posts: 1,581 Joined: Dec 2013
RE: Magnetic Card Questions
(12-06-2020 03:00 AM)Dave Britten Wrote:  Holy cow!!! I didn't realize they sold 1000 packs.
Yep they did!

These are the magnetic cards and/or holders packages that was available for the HP-65, HP-67, HP-97 & HP-82104A (HP-41):
Code:
00065-67010    40  blank magnetic cards (with 1 plastic case) 00065-67054   120  blank magnetic cards (with 3 plastic cases) 00097-13141    40  blank magnetic cards (with 1 cards holder) 00097-13143   120  blank magnetic cards (with 3 cards holders, version #1) 00097-13143   120  blank magnetic cards (no cards holder, version #2) 00097-13143    80  blank magnetic cards (no cards holder, version #3) 00097-13206  1000  blank magnetic cards (no cards holder) 00097-13142     3  cards holders

These are the magnetic cards and/or holders packages that was available for the HP-71B, HP-75C and HP-75D:
Code:
82707A         30  blank magnetic cards 82708A        100  blank magnetic cards 82715A          5  notebook cards holder
12-06-2020, 03:42 AM
Post: #12
 Kostas Kritsilas Junior Member Posts: 28 Joined: Sep 2020
RE: Magnetic Card Questions
(12-06-2020 01:53 AM)Sukiari Wrote:  Has anybody explored the possibility of using commonly available magnetic strip on cardboard as a replacement? You can get it in several formulations and it's dirt cheap. There are a finite number of cards and they seem to get more rare and expensive over time.

I wonder how hard it would be to "make" new cards. I think the basic shape is easy to duplicate (just use any of the existing cards as a template), and probably getting the thickness right wouldn't be too hard. What might take some (or a lot of) effort is getting the magnetic material/oxide coating right, in terms of magnetic characteristics and abrasiveness. There are magnetic strips on the back of most bank cards, at least up here in Canada, so getting a magnetic strip onto a plastic substrate is not something that has disappeared as a process. Another approach might be to see the companies that make business card type fridge magnets, maybe they can be pursuaded to make a non magnetic version on a thinner substrate?
12-06-2020, 07:48 AM
Post: #13
 [kby] Member Posts: 162 Joined: Mar 2014
RE: Magnetic Card Questions
There might have been articles on this back in 65 Notes (or PPC Journal, but I would guess the former as I don’t have as many of the latter). I don’t have time to look right now but will check later if no one else has by then; just thought it might jog someone else’s memory better than my own.-kby
12-06-2020, 04:36 PM
Post: #14
 Sylvain Cote Senior Member Posts: 1,581 Joined: Dec 2013
RE: Magnetic Card Questions
(12-06-2020 07:48 AM)[kby] Wrote:  There might have been articles on this back in 65 Notes (or PPC Journal, but I would guess the former as I don’t have as many of the latter).
I did a quick scan of my 65 notes originals and found three small articles that are related to HP-65 magnetic cards.
I have put them in a PDF here.
Sylvain
PS: I have all the 65notes/PPC/CHHU/etc original journals but you can also get them in a PDF format from Jake Schwartz HERE.
12-07-2020, 12:03 AM
Post: #15
 [kby] Member Posts: 162 Joined: Mar 2014
RE: Magnetic Card Questions
Thanks. I think I mostly remembered the pictures from the third article.

I think I’ve always been well-enough stocked with cards and can’t remember a non user-caused mechanical failure to the card. I have more problems with the proliferation of modern computer equipment that has a plethora of signaling (or other) magnets that are strong enough to erase the cards. A minor to moderate inconvenience wrt the pre-recorded cards; moderate to major for user-made original program cards (depending on ease of finding a listing) and a major pain/minor catastrophe for cards that can’t be re-entered from the keyboard or other “normal” means. I’ve taken to putting mist of the mire valuable originals in a metal (ferromagnetic) box for shielding, bau have toyed with trying dome of the msbneyic shielding paper/foil to see if it improves these situations.-kby

(12-06-2020 04:36 PM)Sylvain Cote Wrote:
(12-06-2020 07:48 AM)[kby] Wrote:  There might have been articles on this back in 65 Notes (or PPC Journal, but I would guess the former as I don’t have as many of the latter).
I did a quick scan of my 65 notes originals and found three small articles that are related to HP-65 magnetic cards.
I have put them in a PDF here.
Sylvain
PS: I have all the 65notes/PPC/CHHU/etc original journals but you can also get them in a PDF format from Jake Schwartz HERE.
12-07-2020, 06:58 PM
Post: #16
 Jake Schwartz Member Posts: 289 Joined: Dec 2013
RE: Magnetic Card Questions
This brings back memories of the late Dean Lampman (PPC member #41 and founder of the Dayton, Ohio PPC chapter; also discoverer of "Lampman Split Logic" on the HP-65") recalling to us at the end of the HHC2001 conference in Chicago how he had gotten to beta-test the HP-65 in 1973. HP had supplied only very few mag cards for him to use, so he began to make his own from cutting out small sections of larger-sized cards (like the ones in the HP-9100A/B) and they worked. However, when he gleefully told HP what he had done, they replied with a "cease-and-desist" notice. Another example of "no good deed going unpunished" :-)

Jake
12-07-2020, 10:38 PM (This post was last modified: 12-07-2020 10:39 PM by Sukiari.)
Post: #17
 Sukiari Member Posts: 147 Joined: Dec 2014
RE: Magnetic Card Questions
(12-06-2020 03:42 AM)Kostas Kritsilas Wrote:
(12-06-2020 01:53 AM)Sukiari Wrote:  Has anybody explored the possibility of using commonly available magnetic strip on cardboard as a replacement? You can get it in several formulations and it's dirt cheap. There are a finite number of cards and they seem to get more rare and expensive over time.

I wonder how hard it would be to "make" new cards. I think the basic shape is easy to duplicate (just use any of the existing cards as a template), and probably getting the thickness right wouldn't be too hard. What might take some (or a lot of) effort is getting the magnetic material/oxide coating right, in terms of magnetic characteristics and abrasiveness. There are magnetic strips on the back of most bank cards, at least up here in Canada, so getting a magnetic strip onto a plastic substrate is not something that has disappeared as a process. Another approach might be to see the companies that make business card type fridge magnets, maybe they can be pursuaded to make a non magnetic version on a thinner substrate?

Before worrying about the formulation I will probably just try making a template and trying various magnetic strip materials I have lying around. I used to punch holes in DD 3 1/2" floppies so I could format them as high density instead of double when I was a lad and I have quite a few of these disks still, they all work fine - haha! So I think the material's probably not terribly important especially considering the low data density on the card itself.
12-07-2020, 10:57 PM (This post was last modified: 12-08-2020 07:59 AM by Kostas Kritsilas.)
Post: #18
 Kostas Kritsilas Junior Member Posts: 28 Joined: Sep 2020
RE: Magnetic Card Questions
(12-07-2020 10:38 PM)Sukiari Wrote:
(12-06-2020 03:42 AM)Kostas Kritsilas Wrote:  I wonder how hard it would be to "make" new cards. I think the basic shape is easy to duplicate (just use any of the existing cards as a template), and probably getting the thickness right wouldn't be too hard. What might take some (or a lot of) effort is getting the magnetic material/oxide coating right, in terms of magnetic characteristics and abrasiveness. There are magnetic strips on the back of most bank cards, at least up here in Canada, so getting a magnetic strip onto a plastic substrate is not something that has disappeared as a process. Another approach might be to see the companies that make business card type fridge magnets, maybe they can be pursuaded to make a non magnetic version on a thinner substrate?

Before worrying about the formulation I will probably just try making a template and trying various magnetic strip materials I have lying around. I used to punch holes in DD 3 1/2" floppies so I could format them as high density instead of double when I was a lad and I have quite a few of these disks still, they all work fine - haha! So I think the material's probably not terribly important especially considering the low data density on the card itself.

I remember doing that, way back when. It worked about 90-95% of the time, but some did end up not formatting correctly, or later on, spontaneously losing their data.

I don't have any floppy diskettes around any more. It seems like a lot of magnetic media has gone the way of the dodo bird. Even things like QIC tapes, VHS/8mm/4mm and audio cassettes are getting hard to come by. I can't find any of them as new, and many are now "collectible" items, overpriced to the extent that you may as well just by the regular magnetic cards.
12-08-2020, 05:28 AM
Post: #19
 Sukiari Member Posts: 147 Joined: Dec 2014
RE: Magnetic Card Questions
(12-07-2020 10:57 PM)Kostas Kritsilas Wrote:
(12-07-2020 10:38 PM)Sukiari Wrote:  Before worrying about the formulation I will probably just try making a template and trying various magnetic strip materials I have lying around. I used to punch holes in DD 3 1/2" floppies so I could format them as high density instead of double when I was a lad and I have quite a few of these disks still, they all work fine - haha! So I think the material's probably not terribly important especially considering the low data density on the card itself.

I remember doing that, way back when. It worked about 90-95% of the time, but some did end up not formatting correctly, or later on, spontaneously losing their data.

I don't have any floppy diskettes around any more. It seems like a lot of magnetic media has gone the way of the dodo bird. Even thinks like QIC tapes, VHS/8mm/4mm and audio cassettes are getting hard to come by. I can't find any of them as new, and many are now "collectibly" items, overpriced to the extent that you may as well just by the regular magnetic cards.

AFAIK there are only three ostensible manufacturers of minicassettes left. A US company, which is probably mostly supported by the government, a Chinese company, which offeres cassettes under different trade names and with different colors and labels, but clearly all on the same equipment, and Sony which some people think use the Chinese company now.
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