ACT available

[PANAMATIK]

(01-29-2015 08:54 PM)Dieter Wrote:  Hallo, Bernhard –

(01-28-2015 09:10 AM)PANAMATIK Wrote:  You can edit a 12-digit welcome string with all numeric digits, and - r F o E G H P I A B d L S.
(...)
The Hex character set is 0123456789A1.2.dEF, dots add ten to the digit. B is 1 with dot, C is 2 with dot.

Hmm... wouldn't it make more sense to add a (lowercase) b and c for displaying hex numbers, even if two other characters like H or P would have to be dropped? Yes, this way you would lose the "HP" greeting. Which of course is nice, but it is worth more than a decent hex display? Just my 2 cents... ;-)

Thanks for your 2 cents...

I agree very much to your statement. But I don't have the choice to drop the H and P for b and c. The few segment combinations that can be displayed are hard coded in the HP chip on the other side of the printed circuit board! Do you remember the old SN7447AN TTL segment driver chip? Thats the kind of segment driver used in the old woodstock HPs. No way to display lower case b or c. Those were the times.

Perhaps I didn't write clearly enough, I wanted to show you, that I already tried any possible tricks, to outsmart the HP-25 display hardware, to transform it to be at least a three-quarter alphanumerical calculator (fully numerical 10 digits and half alpha 13 letters).

(01-29-2015 08:54 PM)Dieter Wrote:  BTW - I own a 29C that suddenly stopped working. It turns on, but all it displays is a row of zeroes: 0000000000. No, the batteries were never charged inside the calculator (in fact I used two standard AA NiMHs with an external charger). But maybe you can say if this is symptomatic for a defectice ACT chip?!

Dieter

There are only four electrical serial communication signals between the ACT chip and the display chips, called PHI1, PHI2, ISA and RCD. If you see 000000000000 in the display it is a sign that the ACT is producing the clock signals PHI1,PHI2 and RDC correctly, but the data signal ISA remains 0V. The display driver interprets 4-serial bits at low level as number zero and displays the six segments abcdef, which is number 0 for all digits. Perhaps only the ISA signal line is disconnected or the ACT is defective, I don't know.

Anyway it can be repaired soon by he new ACT for HP-29C which I'm working on.

Bernhard

[Dieter]

(01-29-2015 09:24 PM)PANAMATIK Wrote:  I agree very much to your statement. But I don't have the choice to drop the H and P for b and c. The few segment combinations that can be displayed are hard coded in the HP chip on the other side of the printed circuit board!

I admit I do not have the slightest idea how electronics and hardware like this work (I'm more interested in software and algorithms), but even with this zero-knowledge I understand that the best software cannot change what's fixed in hardware. ;-)

(01-29-2015 09:24 PM)PANAMATIK Wrote:  Perhaps I didn't write clearly enough, ...

Well, in this case it's obviously me as the recipient of the message, I assume... #-)

(01-29-2015 09:24 PM)PANAMATIK Wrote:  There are only four electrical serial communication signals between the ACT chip and the display chips, called PHI1, PHI2, ISA and RCD. If you see 000000000000 in the display it is a sign that the ACT is producing the clock signals PHI1,PHI2 and RDC correctly, but the data signal ISA remains 0V. The display driver interprets 4-serial bits at low level as number zero and displays the six segments abcdef, which is number 0 for all digits. Perhaps only the ISA signal line is disconnected or the ACT is defective, I don't know.

If you don't now I don't either. ;-) But...

(01-29-2015 09:24 PM)PANAMATIK Wrote:  Anyway it can be repaired soon by he new ACT for HP-29C which I'm working on.

Great. This could mean a new life for this beauty after four years in the drawer *sniff*.

Dieter

[PANAMATIK]

(11-20-2014 02:50 AM)Katie Wasserman Wrote:  

(11-19-2014 11:03 PM)PANAMATIK Wrote:  However, I tested HP-21 and HP-25. Also HP-10, HP-22 and HP-27 should be candidates for a direct replacement, but I cannot promise until somebody could prove it. It needs just some weeks to wait until I can deliver the first units.

The HP-27 uses NMOS technology not PMOS like the 21, 22 and 25 67, 97, etc.. Did you design your "chip" to handle both kinds of logic? That would be quite a challenge I think.

Thanks to another member here, I could measure today the ACT signals of a HP-27 for the first time. I was not able to unsolder its ACT, because its working very well and looks very nice inside. I will not say it would break my heart to remove it, but something said to me: prefer to wait for a better opportunity, until I get a defective one.

As told above I did design the new ACT only for PMOS HP-25 design. And later I found that it worked also on the mixed PMOS/CMOS design of the HP-25C. Can you image my great surprise, when looking at the signals on the oscilloscope and looking to my schematic, that theoretically it should work without changes also for the NMOS HP-27?

The voltage levels for the Phi1/Phi2 clocks were generated by PNP transistors in my design, that get the negative Voltage from the HP calculators power supply. The PMOS level is 6,4V to -12V. The NMOS is 6,4V to 0V. And my design automatically generates 0V instead of -12V when inserted into the HP-27. The VGG signal is 0V in the HP-27. I didnt plan that, and perhaps there are not so many defective HP-27s out there. But if it becomes true, that the ACT works also in NMOS design, then I dont really know why I deserve this.

See my manual, which includes also the schematic.

http://www.panamatik.de/ACTManual.pdf

Bernhard

[PANAMATIK]

I make final tests for the ACT these days with as many calculators as I can.

Five of the calculators below are running with the new ACT: HP-21 HP-22 HP-25 HP-25C HP-29C

   

All others are working, but I didnt have charged batteries at hand for all.

Bernhard

[rprosperi]

(02-03-2015 12:56 PM)PANAMATIK Wrote:  I make final tests for the ACT these days with as many calculators as I can.

Five of the calculators below are running with the new ACT: HP-21 HP-22 HP-25 HP-25C HP-29C

All others are working, but I didnt have charged batteries at hand for all.

Bernhard

Thanks for great photo Bernhard!

Unlike on Facebook, I love family photos here on MoHPC.

From above notes, it looks like the 27 will also be possible, thus the entire family will be supported (with that sticky question about the 67 and 97 "really" being part of the family - a religious issue, not a technical one, imho).

[PANAMATIK]

(02-03-2015 06:29 PM)rprosperi Wrote:  Thanks for great photo Bernhard!

Unlike on Facebook, I love family photos here on MoHPC.

From above notes, it looks like the 27 will also be possible, thus the entire family will be supported (with that sticky question about the 67 and 97 "really" being part of the family - a religious issue, not a technical one, imho).

From my point, 67 and 97 are different technically. At least I know the HP-97 from inside, it has additional chips for keyboard card reader and printer. So let's exclude them for technical reasons, then the new ACT supports indeed the whole family.

But I want to include more relatives later, then I hope to support the whole extended tribal family at someday - and the family photos must be made from greater distance.

Bernhard

[Mark Hardman]

(02-03-2015 06:29 PM)rprosperi Wrote:  Thanks for great photo Bernhard!

Unlike on Facebook, I love family photos here on MoHPC.

From above notes, it looks like the 27 will also be possible, thus the entire family will be supported.

I have to agree that it is a very handsome family indeed.

The HP-27 in the photo is named Bruce Lee. Isn't that correct Bernhard?

Its a pity that Bruce was too well put together to operate on. I was looking forward to you being able to extract the ROM image for derivative work on iOS and Android emulators.

[PANAMATIK]

(02-03-2015 08:06 PM)Mark Hardman Wrote:  I have to agree that it is a very handsome family indeed.

The HP-27 in the photo is named Bruce Lee. Isn't that correct Bernhard?

Yes, that's correct!

   

He always used the scientific functions to calculate his stunts. Even more then he used the financial functions afterwards. Finally we know, why he made this successful career, it was based on HP calculators.

Bernhard

[PANAMATIK]

(02-03-2015 08:06 PM)Mark Hardman Wrote:  I was looking forward to you being able to extract the ROM image for derivative work on iOS and Android emulators.

Well, please correct me if I'm wrong, or I am slow on the uptake, as far as I know all the woodstock calculators microcode is already extracted and available in the public domain. If not, please tell me.

Am I the first, who can read calculators ROMs actively? Of course I can extract any HP ROM code, including bank switched ROMs. Does any developer need HP-29C or HP-27 ROM microcode?

Bernhard

[Mark Hardman]

(02-03-2015 10:39 PM)PANAMATIK Wrote:  

(02-03-2015 08:06 PM)Mark Hardman Wrote:  I was looking forward to you being able to extract the ROM image for derivative work on iOS and Android emulators.

Well, please correct me if I'm wrong, or I am slow on the uptake, as far as I know all the woodstock calculators microcode is already extracted and available in the public domain. If not, please tell me.

Am I the first, who can read calculators ROMs actively? Of course I can extract any HP ROM code, including bank switched ROMs. Does any developer need HP-29C or HP-27 ROM microcode?

Bernhard

Before it was taken down, Eric's Nonpareil distribution only included Woodstock ROM images for the HP-21 and HP-25. The Calculator Models table on his site would be additional evidence that only these models were supported.

If the ROMs for the HP-22, HP-27 and HP-29C were ever extracted, they were not, to my experience, ever made available to the Community.

[PANAMATIK]

(02-03-2015 11:12 PM)Mark Hardman Wrote:  If the ROMs for the HP-22, HP-27 and HP-29C were ever extracted, they were not, to my experience, ever made available to the Community.

HP-22 microcode is already for download here:

http://www.panamatik.de/html/download.html

I extracted also the HP-29C ROM code and added for download.

If Mark is right, this is the first release of the HP-29C ROM code.

Bernhard

[PANAMATIK]

Hello everybody,

I want to inform you, that today I sent the first ACTs and they can be ordered now officially.

The release is stable and is tested on HP-21, HP-22, HP-25 HP-25C HP-29C , the last not yet working in PRGM mode.

Please send PM or contact via e-mail. You can also wait for some more feedback from other members in one or two weeks.

I hope now, that my design will work on any woodstock calculators of the above models, not just on the ones I tried. I did my best to achieve this, even without available datasheets. I could not test on so many calculators I liked, because they are rare. I could not look easily inside of the original ACT, because this needs even more research and time. I could not make it without having costs, because the small size needed a professional manufacturer. With all the work others have already done before, and expressing here my great respect to the original first "nonpareil" emulator, at least I could have made something that it was thought for. I would be proud, if any of you can also give back a few vintage calculators a new life.

Bernhard

[Frido Bohn]

I received today the HP-25 repair kit. Besides of the items needed to manage the chip transplantation it came with a fancy laminated quick guide. Thank you Bernhard!

I will wait until I have some quiet minutes before proceeding with its installation. The desoldering will be the most critical part I guess. Hopefully, I don't manage to fry the circuit lines.
Anyway, the Vorfreude (anticipated happiness) is huge, and outweighs any anxieties by far.

Cheers
Frido

   

[PANAMATIK]

(02-12-2015 06:11 PM)Frido Bohn Wrote:  I received today the HP-25 repair kit. Besides of the items needed to manage the chip transplantation it came with a fancy laminated quick guide. Thank you Bernhard!

I will wait until I have some quiet minutes before proceeding with its installation. The desoldering will be the most critical part I guess. Hopefully, I don't manage to fry the circuit lines.
Anyway, the Vorfreude (anticipated happiness) is huge, and outweighs any anxieties by far.

Cheers
Frido

You were not the first, whom I sent the repair kit, but the first who received it!

Desoldering is not too difficult, because the HP-25 pad holes are bigger than usual. Well, I did it several times without problems, but I had the advantage of a good vacuum soldering iron. Hope yours is also working well. Be patient with each pin!

Good luck
Bernhard

[Mark Hardman]

(02-12-2015 06:54 PM)PANAMATIK Wrote:  You were not the first, whom I sent the repair kit, but the first who received it!

Desoldering is not too difficult, because the HP-25 pad holes are bigger than usual. Well, I did it several times without problems, but I had the advantage of a good vacuum soldering iron. Hope yours is also working well. Be patient with each pin!

Good luck
Bernhard

The two ACTs arrived today. Very fast shipping from Germany! I have to agree that the laminated QRG is a very nice touch.

I have a worthy victim prepared for the procedure this weekend. Provided the patient does not die, I will post pictures of the results.

[Nigel (UK)]

(02-05-2015 09:34 PM)PANAMATIK Wrote:  Hello everybody,

I want to inform you, that today I sent the first ACTs and they can be ordered now officially.

The release is stable and is tested on HP-21, HP-22, HP-25 HP-25C HP-29C , the last not yet working in PRGM mode.

Please send PM or contact via e-mail. You can also wait for some more feedback from other members in one or two weeks.

I hope now, that my design will work on any woodstock calculators of the above models, not just on the ones I tried. I did my best to achieve this, even without available datasheets. I could not test on so many calculators I liked, because they are rare. I could not look easily inside of the original ACT, because this needs even more research and time. I could not make it without having costs, because the small size needed a professional manufacturer. With all the work others have already done before, and expressing here my great respect to the original first "nonpareil" emulator, at least I could have made something that it was thought for. I would be proud, if any of you can also give back a few vintage calculators a new life.

Bernhard

Mine arrived today - it looks great! I hope to install it soon.

I have a question. When installing the new ACT is it worth removing the RAM/ROM chips on a HP-25 if they are faulty or even if they are not, so as to reduce battery drain?

Thank you again for this wonderful creation!

Nigel (UK)

[PANAMATIK]

(02-13-2015 06:27 PM)Nigel (UK) Wrote:  I have a question. When installing the new ACT is it worth removing the RAM/ROM chips on a HP-25 if they are faulty or even if they are not, so as to reduce battery drain?

Thank you again for this wonderful creation!

Nigel (UK)

What I really cannot know: how many different kinds of chip damage in any calculator can occur. If theoretically one of the RAM/ROM chips have a short, then they must be replaced, but I don't know whether that is a real scenario. Normally, even if they are damaged and don't pull some signal lines high or low, they can be left at their place. I never replaced them in my calculators.

I don't know how much current you will spare, when you remove them, it cannot be too much. Therefore I would not recommend to replace the RAM/ROMs just for reducing battery drain, it will not be worth enough, and you have additional risk to damage some copper trace.

The only reason could be, if you want to sell/give them somebody as spare parts.

Good luck also for your calculator
Bernhard

[Frido Bohn]

Found some quiet minutes yesterday to install Bernhard's ACT in my venerable HP-25. The desoldering procedure was really wearisome. Generally all went well but there was one pin that refused perseveringly the removal of tin and took about 50% of the total time to remove the original chip. After cleaning up the pin holes from remains of tin and probing the openings with a needle of sufficient gauge I managed to insert the socket strips and soldered them on the board. The new ACT could be plugged into the socket with a bit of forth and back movement. I reassembled the two boards and checked whether all was working properly. And yes, upon switching it on the calculator gave notice with a personal greeting - thank you Bernhard for this little extra!

However, as I reassembled the calculator completely, the display either didn't work at all or showed only random signals. First I was appaled and worried that somethings went really wrong but I noticed soon that the display changed when I pressed on the keyboard. I suspected a mechanical cause, and indeed, after opening, I realized that the new ACT had some play within the socket strip. My workaround was to put some foam plastic on the new ACT, so the circuit board of the keyboard would excert some pressure on the chip when both boards were reassembled.
This strategy works well so far and I am enjoying now the full funcionality of an HP-25E.

To prevent contact issues of the new ACT with the socket I would recommend to install the chip with the socket strips attached onto the board first and solder the socket pins on the keyboard with this kind of in situ technique.
I don't know if this is a good idea and I am sure that it is due to my inexperience that things became a little awkward.

Anyway, the new ATC with its extended features is really a marvelous piece and moves the good old HP-25 in an area where no one could have imagined.

Thank you again, Bernhard!
Frido

[PANAMATIK]

(02-14-2015 07:01 AM)Frido Bohn Wrote:  Found some quiet minutes yesterday to install Bernhard's ACT in my venerable HP-25. The desoldering procedure was really wearisome. Generally all went well but there was one pin that refused perseveringly the removal of tin and took about 50% of the total time to remove the original chip. After cleaning up the pin holes from remains of tin and probing the openings with a needle of sufficient gauge I managed to insert the socket strips and soldered them on the board. The new ACT could be plugged into the socket with a bit of forth and back movement. I reassembled the two boards and checked whether all was working properly. And yes, upon switching it on the calculator gave notice with a personal greeting - thank you Bernhard for this little extra!

However, as I reassembled the calculator completely, the display either didn't work at all or showed only random signals. First I was appaled and worried that somethings went really wrong but I noticed soon that the display changed when I pressed on the keyboard. I suspected a mechanical cause, and indeed, after opening, I realized that the new ACT had some play within the socket strip. My workaround was to put some foam plastic on the new ACT, so the circuit board of the keyboard would excert some pressure on the chip when both boards were reassembled.
This strategy works well so far and I am enjoying now the full funcionality of an HP-25E.

To prevent contact issues of the new ACT with the socket I would recommend to install the chip with the socket strips attached onto the board first and solder the socket pins on the keyboard with this kind of in situ technique.
I don't know if this is a good idea and I am sure that it is due to my inexperience that things became a little awkward.

Anyway, the new ATC with its extended features is really a marvelous piece and moves the good old HP-25 in an area where no one could have imagined.

Thank you again, Bernhard!
Frido

Hello Frido,

Congratulations! Again you were first!

Thank you for sharing your detailed experience. Of course, there could be found some helpful improvements for the replacement procedure, which I didn't describe in the manual, like soldering with inserted chip. It assures, that the socket is adjusted well. Normally when I solder a socket strip, I first fix only one pin, then when having one hand free I can adjust it more accurately, then fixing the other pins.

When there is a pad, which don't wants to cooperate, I made the experience, that filling it again with fresh tin, and start again, could be helpful. And dragging the pin to the other side or in the middle of the pad hole while soldering is sometimes a little trick for getting the tin out better. Unfortunately, the experience grows only when you repeat the replacement procedure and this it not the normal case.

It makes me really happy (and I'm relieved) , that you finally succeeded and now have a fully functioning HP-25E. Enjoy!

I hope all others, who received the repair kit, will follow you soon.

Bernhard

[PANAMATIK]

(11-20-2014 02:50 AM)Katie Wasserman Wrote:  The HP-27 uses NMOS technology not PMOS like the 21, 22 and 25 67, 97, etc.. Did you design your "chip" to handle both kinds of logic? That would be quite a challenge I think.

Yes, I did! Without knowing, I designed the ACT also for NMOS technology. But now I know it.

Also the HP-27 with damaged ACT/ROM/RAM can be repaired with the new ACT!

Today my engineering mind won over the collectors concerns. I decided to unsolder the NMOS ACT of my beautiful working HP-27.

Here it is for sale

It is still alive, because the calculator runs when I put it back into its new socket.

But then what will happen when I insert the new ACT? I was a little bit excited. Nothing happened! The display remained dark. But now I made some measurements and found that there has to be changed only one Pin, which can be easily done in the new ACT circuit. And it started with 0.00 in the display!

I will check the HP-27 ROM code and need some time to confirm that every function is working.

I hope that nobody has thrown away a damaged HP-27 in the past. It can be easily repaired now.

Bernhard