If I were to buy an LED model...

[HP67]

(11-09-2019 11:07 AM)Maximilian Hohmann Wrote:  And if you want the ultimate LED calculator from HP you need to look for an HP-67. That one is the latest (and best - or at least equal to the Ti59) LED calculator ever designed. But they have become rare and rather expensive and usually require some maintenance (card reader) before they can be used.

As you might expect from my forum name, yeah, this. The 67 is a tank, it's a brick, it's heaven in a calculator's body. I don't agree it's at all comparable to any TI (that I have seen). The build quality on HP just stomps the TIs to death. Functionality may go either way depending on which model but all the TIs I have ever owned have been poorly built, paint wore off, and they died untimely deaths. Just no comparison.

The 67s were becoming very expensive but lately I have seen a surprising number online for reasonable and even cheap prices. Keep looking around if you want one. I'm starting to believe it's possible to get one in decent condition without paying an arm and a leg.

[Maximilian Hohmann]

Hello!

(11-12-2019 08:50 PM)HP67 Wrote:  I don't agree it's at all comparable to any TI (that I have seen). The build quality on HP just stomps the TIs to death. Functionality may go either way depending on which model but all the TIs I have ever owned have been poorly built, paint wore off, and they died untimely deaths. Just no comparison.

My father got an HP67 from his employer in 1977 (or 1978?) and I got my Ti59 in 1979. Both calculators still work after 40+ years and my Ti does not look any worse than when it was new. The original batteries are long dead on both calculators.
But I agree that the bulid quality is not the same, my Ti59 had to be sent for repair once and the keyboard has become somewhat bouncy over the years, but it is still useable. Functionally the Ti59 beats the HP67, it has more memory and the plug-in software modules add lots of extra features. And all that at 1/2 the price of the HP.
But in any case an HP67 belongs in every calculator collection!

Regards
Max

[Dave Britten]

Update!

I bought a very nice 25 from DaveBr, with the case, manual, and applications book. I've been tinkering with it off and on all afternoon/evening, trying out various programs from the books and such. It's really impressive how much you can do with just 49 steps, and no subroutines or indirect addressing. Yes, you can do more with a 42S, but you can still do a lot with a 25.

I got a set of 4 flat-top NiMHs from Batteries Plus, so I can have two ready to go if I need to throw the current pair on the charger. They seem to fit well in the little 3D-printed battery pack.

I didn't realize how tiny the Woodstocks are. My TI-58C looks gigantic next to it.

I was able to write the usual mod 30 prime factor finder on it, but without subroutines, you instead have to build a loop that strips digits off of a "stream" of offsets stored as .2122 and .42424626, and it ends up being slower than just testing all the odd numbers.

I still plan to keep an eye out for an 80, and maybe a Spice too.

[Don Shepherd]

(11-15-2019 01:43 AM)Dave Britten Wrote:  I was able to write the usual mod 30 prime factor finder on it, but without subroutines, you instead have to build a loop that strips digits off of a "stream" of offsets stored as .2122 and .42424626, and it ends up being slower than just testing all the odd numbers.

I think that algorithm will live as long as you and I do!

You know you're not going to be happy until you get a 65, the first programmable handheld calculator and the only calculator that can process the digits 8 and 9 as octal values!

I'm still building my 1950's data processing punch card system in anticipation of the coming armegeddon. I've got 2 portable keypunches now, 2 Port-a-punch's, 2 IBM printer control-tape punches, and 4,000+ blank 80-column punchcards. Now all I need to do is build a fallout shelter to put them all in.

[DaveBr]

(11-15-2019 01:43 AM)Dave Britten Wrote:  Update!

I bought a very nice 25 from DaveBr, with the case, manual, and applications book. I've been tinkering with it off and on all afternoon/evening, trying out various programs from the books and such. It's really impressive how much you can do with just 49 steps, and no subroutines or indirect addressing. Yes, you can do more with a 42S, but you can still do a lot with a 25.

I got a set of 4 flat-top NiMHs from Batteries Plus, so I can have two ready to go if I need to throw the current pair on the charger. They seem to fit well in the little 3D-printed battery pack.

I didn't realize how tiny the Woodstocks are. My TI-58C looks gigantic next to it.

I was able to write the usual mod 30 prime factor finder on it, but without subroutines, you instead have to build a loop that strips digits off of a "stream" of offsets stored as .2122 and .42424626, and it ends up being slower than just testing all the odd numbers.

I still plan to keep an eye out for an 80, and maybe a Spice too.

I’m happy to hear that the HP-25 arrived and you are already writing programs on it. The HP-25 was my “go to’ calculator for years and I can’t even count the number of programs I wrote on it to solve both work and home problems.
I have an HP-80 and it is a wonderful financial calculator. I use it often for personal finance. I have a number of HP financial calculators, but I prefer the HP-80. There is something deeply satisfying watching the blinking LEDs while it works out a solution.

[Dave Britten]

Here's the ol' 15-puzzle solvability checker, ported pretty much directly from Don's 65 version. There are a couple of notable changes:

1. No labels, so all GTOs are line-number-based.
2. R/S doesn't terminate digit entry, so there's an ENTER in step 4 to explicitly terminate entry (otherwise the next step would modify X rather than lifting the stack first).
3. y^x isn't super precise, so the y^x call is followed by .5 + INT to round to the nearest integer.

To run it:

Enter the row number of the blank, press R/S, then enter the tiles left to right, top to bottom, with R/S after each one.

Code:

01    CLR REG
02    STO 2
03    R/S
04    ENTER
05    2
06    X><Y
07    y^x
08    .
09    5
10    +
11    INT
12    STO+ 1
13    RCL 1
14    X><Y
15    /
16    2
17    /
18    INT
19    STO 4
20    2
21    /
22    INT
23    STO 4
24    LASTx
25    FRAC
26    2
27    *
28    STO+ 2
29    RCL 4
30    X!=0?
31    GTO 20
32    RCL 2
33    R/S
34    GTO 04

[Geoff Quickfall]

Personally,

The 67 over the 34C due to the memory card option. I have too many programs that I require for just the 34C with continuous memory.

Love the 34C but just not enough resident memory.

Now, if you are not into fully original restored then I suggest the 29C with Bernhard’s Panamatik low power module. I use this on the flight deck just for the WOW factor:

1) RTC clock with date and alarm, yes a piezo is installed!

2) count up or down timer,

3) get ready, alphanumeric ability in coding the programs instead of key codes within program.

4) fully mergeable 92 line programs allowing a program of many hundreds of lines. I have one program that calls automatically two other programs allowing for a seamless 297 line program.

5) IR printing

6) may have gps capability if you want!

Unabashed promotion here but apropos to the thread. My 29C was a dead unit from eBay in otherwise pristine shape. I know you can format any Woodstock into the 29C but I wanted the original keyboard.


Of course nothing beats inserting a card into the 67 and seeing the millennial sitting next to me with an open mouth ;-)

Now when it comes to research in April I am resurrecting my 41C (41CL) and HPIL. This will be the goto calc and controller in my lab when I start school again in April. I used it in 1984 (CX version) with HPIL and don’t feel like learning a new system,

Geoff

[Paul Dale]

Quote:Of course nothing beats inserting a card into the 67 and seeing the millennial sitting next to me with an open mouth ;-)

I've experienced this effect at work with a 65 I've not tried a 67 or 97 but will eventually.


I concur about the Woodstock low power. A wonderful upgrade. It can emulate a 34C with a keyboard overlay too. The 34C is a personal favourite -- it was my first HP, although I'd used others before.


Pauli[/quote]

[Dave Britten]

(11-16-2019 05:19 AM)Paul Dale Wrote:  

Quote:Of course nothing beats inserting a card into the 67 and seeing the millennial sitting next to me with an open mouth ;-)

I've experienced this effect at work with a 65 I've not tried a 67 or 97 but will eventually.


I concur about the Woodstock low power. A wonderful upgrade. It can emulate a 34C with a keyboard overlay too. The 34C is a personal favourite -- it was my first HP, although I'd used others before.


Pauli

I'd love to get the Panamatik board, but no way would I gut a 25 that's in such great condition. If I came across a dirt-cheap 29 with a dead ACT, I'd definitely consider it.

[Don Shepherd]

(11-16-2019 01:53 AM)Dave Britten Wrote:  Here's the ol' 15-puzzle solvability checker, ported pretty much directly from Don's 65 version.

This thread contains the 65, 67, and 17b versions of the 15 puzzle solvability checker that Dave referred to.

I was indebted to Dave for showing me how to implement this program on the 65. I particularly like the 17b version, it demonstrates a good use of the ITEM solver function; you can enter the tile positions in a list rather than entering them during the execution of the program.

[Archilog]

RE: If I were to buy a LED model...
... today I would buy a HP-21 (even with damaged ACT), send it to Panamatik in order to obtain the best red LED HP ever (see http://panamatik.de/index.html).
(as it was probably said before, but better twice than never).

[Bill Duncan]

My favourite, and still running like a tank, was the hp-29c. So much better than the hp-25 that preceded it..