The HP-65 was not only HP's first programmable scientific, but it could also read and write magnetic cards. There were several 'pac's of cards allowing it to tackle financial, astronomical, aviation, electrical and other speciality field calculations. The buttons were double shot and have a lovely tactile click. The red LED screen is remarkably crisp and easy to read.
I think I like the buttons and the highly-specialised functionality. At least that's what I think when people say 'what's the point, you have a far more powerful calculator in your pocket already'. Yes, one without buttons.
These are the tests which can give you quite a good profile and accuracy rating for your financial calculator. Any more contributions and confirmation are very much appreciated and I will update the swissmicros page (though I may need to move it off there at some point).
| # | Ref | N | I%YR | PV | PMT | FV | P/YR | Mode |
|----|------------|--------------|-----------|----------|--------------|-----------|------|-------|
| 1 | DM | 38 x 12 | 5.25% | 270'000 | ? | 0 | 12 | end |
| 1b | DM | 38 x 12 | ? | 270'000 | -14'584/12 | 0 | 12 | end |
| 2 | SlideRule | 360 | 15% → 12% | 100'000 | ?-? | 0 | 12 | end |
| 3 | Kahan 1983 | 60x60x24x365 | 10% | 0 | -0.01 | ? | =N | end |
| 4 | DM | 480 | 0 → ? | 100'000 | ?→ PMT | 0 | 12 | end |
| 5 | Dieter | 10 | ? | 50 | -30 | 400 | 1 | end |
| 6 | Dieter | 10 | ? | 50 | -30 | 80 | 1 | end |
| 7 | A Chan | 10 | ? | -100 | 10 | 1e-10 | 12 | end |
| 8 | Miguel | 32 | ? | -999'999 | 0 | 1e6 | 1 | end |
| 9 | DM | ? | 25 | 100000 | -2083.333334 | 0 | 12 | end |
| 10 | DM | ? | 25 | 100000 | -2040.816327 | 0 | 12 | begin |
| 11 | robve | 60x24x365 | 1/6% → ? | 0 | -0.01 | ?→ FV | =N | end |
| 12 | robve | 40 | ? → I%YR | 900 | -400 | -1000 → ? | 1 | begin |
2: https://www.hpmuseum.org/forum/thread-20707.html
3: https://www.hpmuseum.org/forum/thread-1012.html
5, 6: https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv021.cgi?read=234439
7: https://www.hpmuseum.org/forum/thread-18359-post-161549.html#pid161549
8: https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv017.cgi?read=120592
11, 12: https://www.hpmuseum.org/forum/thread-16565-page-2.html
Puzzle 2 is from here, and needs you to calculate PMT given n = 360, I%YR = 15%, PV = 100'000, FV = 0, then calculate PMT, but with I%YR = 12%. Subtract the two results, and put that back into PMT, then change n = 36 and I%YR = 15% again, and calculate PV.
Puzzle 3: you may need to divide I%PY by N depending on how your calculator handles i vs I%YR and what the limit is on P/YR.
Puzzle 4 needs you to calculate PMT first given I%YR = 0, then re-input this back into PMT and calculate I%YR. On the HP-12c this is best done by pressing x<>y twice before putting back into PMT.
Puzzle 11: calculate for FV first, re-input back to FV and compute I%YR.
Puzzle 12: calculate for i first, re-input back into i and compute FV.
The other puzzles are just a solve for '?'.
They can be a bit confusing, so I also did a couple of videos here and here solving them on a DM-42 and HP-12c.
A random shot of my calculator 5000 miles from home while I enjoy a beer near the Pacific. We had been discussing how much water was on earth and what size of a ball it would make. I have no affiliation with the brewing company so apologies for the product placement.
Yes, I also have caps mapped to esc, but done in keyboard firmware so that holding it functions as ctrl.
In neovim I have two escapes mapped to :noh
I tried to play this on an original IBM PC. Without a mouse and only 4 colours. It went badly.
That's lovely - these calculators are very 'dad' style to me also (though my dad had a 70s style Casio). There's something about the voyager HP calculators with their landscape format - they are really satisfying to use, I can see why he kept it on him!
It's a Stilform fountain pen. They are a recent make using machined parts and bock nibs with a nifty magnetic cap. I'm having slight issues with the bock nibs though - they are going to need a bit more work to keep the flow how I like it.
This might be the best looking graphing calculator I've seen.
HP's most accurate financial calculator, oddly enough, and despite only returning the ceiling of solve-for-n.
These were such great machines, so far ahead of their time. I had a 3a, and nothing has beaten the Agenda program on it. I think part of the reason it was so good was that it wasn't a touch screen and the keyboard control was so well thought out, especially tab to bring up a monthly calendar. And what modern calendar has a year view that is useful?
That is a well-filled pen! It looks like others have said this, but nothing has ever beaten my 90s PDA for organising my life.
The Asvine is a poor man's ASC, but it is beautiful and arguably the difference saved covers the DM42. But that's me jumping through mental hoops to justify a purchase of course.
The global problem is that healthcare is costing significantly more as medicine progresses. Almost every Western health system is spending more as a % of GDP each year. The reason is that we are getting much better at treating what were previously very poor prognosis conditions. It wasn't that long ago we had one not very effective treatment for multiple myeloma. If that didn't work, there wasn't much left to do. These days with have around 10+ regimens, and patients are living for much longer and going through 3, 4, 5+ types of treatment before nothing further can be done. These treatments cost up to £50k/month. But they also cost more from your doctor - who now needs to be a superspecialist and spend more time working out exactly how best to sequence your treatment, and you also need more specialist nurse involvement, and more time from day unit nurses to deliver the treatment.
I really don't believe private is the answer. Someone here mentioned Germany has a private system. A quick look on wikipedia shows we spent $4188-5493/capita from 2018-2022, Germany spent $6290-8011 for the same time period - they spend 45.8% more than the UK. I would rather we first try matching our spending with a system we wish to emulate rather than privatise first.
Ha ha, I will bear that in mind for any future posts. However, that is an R/S key on this occasion :)
Ah yes that's a pretty nice graphing calculator, also looks pretty good in pink!