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+--- Thread: Disabling HP65/67 card reader write protect (/thread-12580.html)
Disabling HP65/67 card reader write protect - wallyt - 03-07-2019 06:08 PM
I would like to re-record some pre-recorded cards that seem to have lost their data integrity. I would like to record onto the original factory recorded cards since they have all the program nomenclature nicely printed on them. Has anyone thought of how to do this? I have tried to stick some tape to the end of the card, filling the cut so that the reader thinks it is a recordable card, but have not had much success with this.
Is it possible to temporarily wire a switch to the circuit that detects the card's write protect status, say the pad under the little ball, that I could toggle when I need to record a card?
RE: Disabling HP65/67 card reader write protect - Paul Berger (Canada) - 03-07-2019 06:27 PM
I have done this on a 97. The write protect switch is wired to pin 3 of the card controller chip. Connecting this pin to ground will defeat copy protection. I am pretty sure that it would be the same for a 67 but I do not have one open at this time. I have never seen the inside of a 65, from Tony Duell's schematic it would appear the write protect works the same way ie a non-protected card would ground the write protect line so could likely be defeated in the same manner, according to the schematic this line goes to pin 2 of the hybrid in the 65.
Paul.
RE: Disabling HP65/67 card reader write protect - Don Shepherd - 03-07-2019 06:30 PM
(03-07-2019 06:08 PM)wallyt Wrote: I would like to re-record some pre-recorded cards that seem to have lost their data integrity. I would like to record onto the original factory recorded cards since they have all the program nomenclature nicely printed on them. Has anyone thought of how to do this? I have tried to stick some tape to the end of the card, filling the cut so that the reader thinks it is a recordable card, but have not had much success with this.
Is it possible to temporarily wire a switch to the circuit that detects the card's write protect status, say the pad under the little ball, that I could toggle when I need to record a card?
Wally, I needed to do this too years ago when some of my 65 standard pac cards got too close to a magnet. I forget who told me this, but it works like a charm. Here is what he wrote me:
You can write to protected cards easily with an "unprotect" card - take an old card that you aren't otherwise using and cut its bottom right corner off so its right side is at a 45 degree slope in the upper right corner. Then, if you gently put that card into the exit port of the card reader (the left slot), you can write to a protected (cut corner) card. The protected card will push this one out of its way as it goes through, but this card's pointed corner will fill the gap of the protected card's cut corner, fooling the 65 or 97.
the card looks like this:
RE: Disabling HP65/67 card reader write protect - AndiGer - 03-07-2019 07:35 PM
Just added corners using some kind of cardboard / thick paper
Sorry, picture was not uploaded - maybe too large
Also have a look here: http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv003.cgi?read=5306
RE: Disabling HP65/67 card reader write protect - Thomas Okken - 03-07-2019 09:06 PM
(03-07-2019 06:30 PM)Don Shepherd Wrote: You can write to protected cards easily with an "unprotect" card
How far do you have to push that card in for it to trip the switch? I have never opened my 67 and I have no idea how the mechanism is laid out...
RE: Disabling HP65/67 card reader write protect - burkhard - 03-07-2019 09:31 PM
(03-07-2019 09:06 PM)Thomas Okken Wrote:(03-07-2019 06:30 PM)Don Shepherd Wrote: You can write to protected cards easily with an "unprotect" card
How far do you have to push that card in for it to trip the switch? I have never opened my 67 and I have no idea how the mechanism is laid out...
The reader still works and you have never opened it for repair? Did a prior owner? I didn't think any of them were immune from gummy wheel disease!
RE: Disabling HP65/67 card reader write protect - Thomas Okken - 03-07-2019 09:36 PM
(03-07-2019 09:31 PM)burkhard Wrote:(03-07-2019 09:06 PM)Thomas Okken Wrote: How far do you have to push that card in for it to trip the switch? I have never opened my 67 and I have no idea how the mechanism is laid out...
The reader still works and you have never opened it for repair? Did a prior owner? I didn't think any of them were immune from gummy wheel disease!
I never opened it, but I didn't say it had never been opened. I bought it used on eBay and then sent it to Adam Jones (jones.sebago.lake on eBay) to get the card reader serviced. Then and only then did I try using the card reader!
RE: Disabling HP65/67 card reader write protect - Don Shepherd - 03-07-2019 10:41 PM
(03-07-2019 09:06 PM)Thomas Okken Wrote:(03-07-2019 06:30 PM)Don Shepherd Wrote: You can write to protected cards easily with an "unprotect" card
How far do you have to push that card in for it to trip the switch? I have never opened my 67 and I have no idea how the mechanism is laid out...
I've never opened mine either (gummy wheel fixed by someone who knows what they are doing). As I recall, I just inserted the 45 degree angle card maybe .5 inch into the opening on the left side (until it was gripped) and then tried to write the card inserted in the right side, and that worked. You may need to experiment with +/- .5 inch if it doesn't work the first time, but my memory is that it worked really well without a lot of retries.
RE: Disabling HP65/67 card reader write protect - Thomas Okken - 03-07-2019 11:11 PM
(03-07-2019 10:41 PM)Don Shepherd Wrote:(03-07-2019 09:06 PM)Thomas Okken Wrote: How far do you have to push that card in for it to trip the switch? I have never opened my 67 and I have no idea how the mechanism is laid out...
I've never opened mine either (gummy wheel fixed by someone who knows what they are doing). As I recall, I just inserted the 45 degree angle card maybe .5 inch into the opening on the left side (until it was gripped) and then tried to write the card inserted in the right side, and that worked. You may need to experiment with +/- .5 inch if it doesn't work the first time, but my memory is that it worked really well without a lot of retries.
Hmm, I get Error every time. Then again, I'm not using a cut-down magnetic card, but a strip of thin cardboard cut to the same width and 45° angle at the end. It seems to be a bit thicker than a magnetic card, maybe that's the problem? I am reluctant to cut an actual magnetic card because I don't have that many, and, well, just because.
(I have verified that the card reader reads and writes uncut cards, so that's not the problem.)
RE: Disabling HP65/67 card reader write protect - Don Shepherd - 03-08-2019 12:47 AM
(03-07-2019 11:11 PM)Thomas Okken Wrote:(03-07-2019 10:41 PM)Don Shepherd Wrote: I've never opened mine either (gummy wheel fixed by someone who knows what they are doing). As I recall, I just inserted the 45 degree angle card maybe .5 inch into the opening on the left side (until it was gripped) and then tried to write the card inserted in the right side, and that worked. You may need to experiment with +/- .5 inch if it doesn't work the first time, but my memory is that it worked really well without a lot of retries.
Hmm, I get Error every time. Then again, I'm not using a cut-down magnetic card, but a strip of thin cardboard cut to the same width and 45° angle at the end. It seems to be a bit thicker than a magnetic card, maybe that's the problem? I am reluctant to cut an actual magnetic card because I don't have that many, and, well, just because.
(I have verified that the card reader reads and writes uncut cards, so that's not the problem.)
Well, I can only vouch for the modified mag card, that worked for me.
RE: Disabling HP65/67 card reader write protect - Thomas Okken - 03-08-2019 01:02 AM
(03-08-2019 12:47 AM)Don Shepherd Wrote:(03-07-2019 11:11 PM)Thomas Okken Wrote: Hmm, I get Error every time. Then again, I'm not using a cut-down magnetic card, but a strip of thin cardboard cut to the same width and 45° angle at the end. It seems to be a bit thicker than a magnetic card, maybe that's the problem? I am reluctant to cut an actual magnetic card because I don't have that many, and, well, just because.
(I have verified that the card reader reads and writes uncut cards, so that's not the problem.)
Well, I can only vouch for the modified mag card, that worked for me.
OK, I took a deep breath and cut an actual magnetic card, and tried with that. It went in a lot farther than the cardboard strip before encountering resistance, and I was finally able to get a write-protected card to pass through without Error. Progress!
Unfortunately, the re-written card still gives me Error when I try to read it back. Could be the card itself has gone bad, or maybe I just need to experiment some more to find out exactly how deep the cut-off card should be inserted. Enough for today; to be continued...
RE: Disabling HP65/67 card reader write protect - Don Shepherd - 03-08-2019 01:46 AM
(03-08-2019 01:02 AM)Thomas Okken Wrote:(03-08-2019 12:47 AM)Don Shepherd Wrote: Well, I can only vouch for the modified mag card, that worked for me.
OK, I took a deep breath and cut an actual magnetic card, and tried with that. It went in a lot farther than the cardboard strip before encountering resistance, and I was finally able to get a write-protected card to pass through without Error. Progress!
Unfortunately, the re-written card still gives me Error when I try to read it back. Could be the card itself has gone bad, or maybe I just need to experiment some more to find out exactly how deep the cut-off card should be inserted. Enough for today; to be continued...
Hey, how about an old 80-column IBM card, repurposed to rescue HP-65 mag cards! Think of the history; a card from the 1950's rescuing a card from the 1970's, in 2019!
Now, if only you had an IBM card .....
RE: Disabling HP65/67 card reader write protect - rprosperi - 03-08-2019 02:01 AM
(03-08-2019 01:02 AM)Thomas Okken Wrote: OK, I took a deep breath and cut an actual magnetic card, and tried with that. It went in a lot farther than the cardboard strip before encountering resistance, and I was finally able to get a write-protected card to pass through without Error. Progress!
Unfortunately, the re-written card still gives me Error when I try to read it back. Could be the card itself has gone bad, or maybe I just need to experiment some more to find out exactly how deep the cut-off card should be inserted. Enough for today; to be continued...
Try cleaning the card with a pen eraser (Staedtler Mars, etc.). Sometimes this will clean the oxidation that has built up on the magnetic side of the cards; be careful how you hold the card down while rubbing, it is easy to bend a card. But sometimes, these cards can be too worn or affected by strong enough magnetic fields that they can't be restored to working order again.
Send me your address via PM, I'll mail you some cards.
RE: Disabling HP65/67 card reader write protect - Thomas Okken - 03-08-2019 10:37 PM
(03-08-2019 02:01 AM)rprosperi Wrote: Try cleaning the card with a pen eraser (Staedtler Mars, etc.). Sometimes this will clean the oxidation that has built up on the magnetic side of the cards; be careful how you hold the card down while rubbing, it is easy to bend a card. But sometimes, these cards can be too worn or affected by strong enough magnetic fields that they can't be restored to working order again.
Good idea! It's been so long since my HP-41 days, I'd completely forgotten about the eraser trick. I should have a couple of Staedtler Mars erasers lying around somewhere.
(03-08-2019 02:01 AM)rprosperi Wrote: Send me your address via PM, I'll mail you some cards.
Thank you! But before I take you up on that, I'm going to try some more tests with the card I have mutilated already. I got a pack of AAA lithiums since the alkalines I was using weren't holding up too well under the constant card reader usage -- with these new batteries I should be able to do a nice methodical series of tests without further interruptions. I'll post again tomorrow with my results.
RE: Disabling HP65/67 card reader write protect - wallyt - 03-09-2019 03:58 PM
I just tried the "cut card" method on my HP65 and it worked really well! This might not be as elegant as a hard wire switch but it sure was easier. It defeated the copy protection status and I was able to re-record onto the factory card first try.
Since I am currently attempting a repair on my HP97 printer and have the case open I might look into hard wiring a switch as mentioned above. It would depend on how many bad factory cards I find in my collection.
Thanks to all responders here!
RE: Disabling HP65/67 card reader write protect - AndiGer - 03-09-2019 04:21 PM
I took some pics and attach here. Just "repair" the corners.
Adhesive tape only on the upper side not on the magnetic side.
Andi
RE: Disabling HP65/67 card reader write protect - Don Shepherd - 03-09-2019 07:34 PM
(03-09-2019 03:58 PM)wallyt Wrote: I just tried the "cut card" method on my HP65 and it worked really well! This might not be as elegant as a hard wire switch but it sure was easier. It defeated the copy protection status and I was able to re-record onto the factory card first try.
Since I am currently attempting a repair on my HP97 printer and have the case open I might look into hard wiring a switch as mentioned above. It would depend on how many bad factory cards I find in my collection.
Thanks to all responders here!
Great!
RE: Disabling HP65/67 card reader write protect - Thomas Okken - 03-09-2019 09:14 PM
I finally had success with the cut card method as well. As recommended by Bob, I first cleaned the card I wanted to rewrite; I couldn't find my plastic erasers, but I made do by breathing on the card to get it slightly damp, then gently wiping it with soft cotton (i.e., T-shirt). I altered my cut card slightly: suspecting the angle of the cut was a bit too acute the first time, I cut off another sliver to get it closer to 45°.
I pushed the cut card in about halfway. The right point was easy to find, it's right where you start to feel resistance. Any less far and you get Error while writing, any farther and it won't be pushed out by the card being written, it just slides over. Which may be harmless but who knows.
It still took a couple of attempts, but I was able to restore my SD-15A in the end, so now I have a complete and functioning Standard Pac once again.
Thank you Don and Bob for your advice!
RE: Disabling HP65/67 card reader write protect - [kby] - 05-08-2019 07:45 AM
(03-07-2019 09:31 PM)burkhard Wrote:(03-07-2019 09:06 PM)Thomas Okken Wrote: How far do you have to push that card in for it to trip the switch? I have never opened my 67 and I have no idea how the mechanism is laid out...
The reader still works and you have never opened it for repair? Did a prior owner? I didn't think any of them were immune from gummy wheel disease!
I posted in this thread:
https://www.hpmuseum.org/forum/thread-996.html
about a -67 I was actually using to repair a -65. The -67 looked like it had never been opened (smooth back label not a replacement), but the wheel was dark (rather than the usual golden color) and not gummy or crumbly. Still works (in my -65) today.
Btw the 45° card was from 65 Notes, as well as its variation with only part of the cut.
RE: Disabling HP65/67 card reader write protect - teenix - 05-09-2019 12:44 AM
Hi all,
Just FYI, here is a capture of the switch signals as a card is read on a HP-67.
Yellow - Motor Switch
Blue - Head Switch
Purple - Write Protect Switch
The respective line dropping in voltage indicates the switch closing.
The image indicates a write protected card
If Blue(HDS) and Purple(WPS) close together, the card is not write protected.
cheers
Tony