35S Insanity

[Commie]

(11-30-2024 08:01 PM)Steve Simpkin Wrote:  

(11-30-2024 04:55 PM)naddy Wrote:  ...Is it possible that they didn't have/couldn't use the source code and re-implemented everything from scratch, modeled on the 32SII?

Yes, that is exactly what happened.

Hi guys,

I just want to point out how difficult it is to design a calculator from scratch, bug free, it's almost impossible. Just as you find and fix one bug you find another and another and it goes on and on. I tried to design a hp45 from the ground up, It took me months to design and debug and finally I had a working model only to be let down by ieee 754 binary floats as being inherently inaccurate. This is why everyone making hp clones use nut cpu emulators almost exclusively.

Most of the design engineers, working at hp, were MSc graduates, very clever top guys, they were at least 10 years ahead of everyone else at the time particularly when Bill and Dave were running hp.

Cheers
Darren

[Thomas Klemm]

(11-30-2024 09:05 PM)Commie Wrote:  I tried to design a hp45 from the ground up (…)
This is why everyone making hp clones use nut cpu emulators almost exclusively.

This one even implements the hidden timer: HEWLETT•PACKARD 45

OTOH both DM32 and DM42 from SwissMicros are simulators of the originals.

[Commie]

(11-30-2024 07:00 PM)Johnh Wrote:  But what makes the HP15C-CE appealing and feasible for use now is that it does indeed have i/o support , as developed by the wonderful people here.

Hi,

Why don't the 'wonderful people here' develop a i/o solution for the hp35s then?

[Steve Simpkin]

(11-30-2024 08:32 PM)Thomas Klemm Wrote:  

(11-30-2024 08:01 PM)Steve Simpkin Wrote:  Kinpo then designed the calculator circuitry, hardware, wrote the software and manufactured the calculator for HP.

It appears that these are not the only models.
The “Scientific Calculator” on Kinpo's Consumer Electronics looks like an HP 10bII+ to me.

Kinpo has made a *lot* of current and past calculator models for Texas Instruments, Hewlett Packard, Casio, Canon and Citizen (at a minimum).
http://datamath.org/Featured_Companies.htm#Kinpo

[Johnh]

(11-30-2024 09:36 PM)Commie Wrote:  

(11-30-2024 07:00 PM)Johnh Wrote:  But what makes the HP15C-CE appealing and feasible for use now is that it does indeed have i/o support , as developed by the wonderful people here.

Hi,

Why don't the 'wonderful people here' develop a i/o solution for the hp35s then?

You might notice that there is no hardware built in to support any sort of i/o.

[gentzel]

(11-30-2024 09:36 PM)Commie Wrote:  Why don't the 'wonderful people here' develop a i/o solution for the hp35s then?

Probably because it would require hardware modifications. The 15C-CE has a USB port (albeit one with a very non-standard connector).

[Steve Simpkin]

(11-30-2024 09:36 PM)Commie Wrote:  

(11-30-2024 07:00 PM)Johnh Wrote:  But what makes the HP15C-CE appealing and feasible for use now is that it does indeed have i/o support , as developed by the wonderful people here.

Hi,

Why don't the 'wonderful people here' develop a i/o solution for the hp35s then?

The HP 35s is not a good candidate for any modifications. Unlike the HP-15 CE, its firmware is in ROM instead of Flash memory and cannot be changed. The HP-15 CE has an emulation software layer that was written by HP and is maintainable. This is where the I/O functionality was added. My understanding of the HP 35s firmware is that is was written by Kinpo in poorly documented C/assembly and is not maintainable by HP.

[Thomas Klemm]

(11-30-2024 04:57 PM)naddy Wrote:  It's matrix support is also lacking, FWIW.

At least there are some programs that can be used.

[dm319]

I remember Thomas saying something about free42 never being bug-free. And to be fair to Kinpo, it's different if you have a tight deadline to work to getting a physical calculator onto the market as opposed to making an open-source calculator and allowing everyone to test it for 20 years.

PS Happy Birthday to Free42!! It turned 20 in November.

The talk about Kinpo writing 35s and 33s on 6502 platform makes me think the Rogue 12c was made by Kinpo?

[Steve Simpkin]

(12-01-2024 11:49 AM)dm319 Wrote:  ...
The talk about Kinpo writing 35s and 33s on 6502 platform makes me think the Rogue 12c was made by Kinpo?

Perhaps. According to Wikipedia, the HP-12C Platinum is a complete reimagination of the HP-12C that was manufactured by Kinpo Electronics for HP. Unlike the HP-12C which, (more or less) run the same 1981 firmware on a real or emulated HP "NUT" processor, the HP-12C Platinum has completely rewritten software running on a 6502 processor core.,
https://en.wikipedia.org/wiki/HP-12C#HP_.../_Prestige

Additional HP-12C platinum origin information from Robert Prosperi (rprosperi):
"The 12CP was created to add a near-12C financial calculator with algebraic operation to the product lineup as the EU market (for financial use at least) were not willing to adopt RPN-based models. Since grafting-on algebraic features was no longer feasible (Nut CPU development was all done in assembler) they chose to reimplement the machine from scratch in C on a readily available and cheap CPU, and so.... that's why while it is very similar, the internal math and results are not identical."
https://www.hpmuseum.org/forum/thread-22...#pid190353

Additional information:
http://www.brouhaha.com/~eric/hpcalc/voy...iants.html

https://www.hpcc.org/datafile/V22N3/platinum.pdf

[AnnoyedOne]

(12-01-2024 11:49 AM)dm319 Wrote:  ...makes me think the Rogue 12c was made by Kinpo?

That'd be my guess.

They probably have experience with Sunplus/Generalplus stuff plus the tools.

That said someone likely asked them to do it.

A1

[dm319]

I wrote a reply but decided to put it in another thread.

[floppy]

(11-30-2024 12:44 AM)everettr Wrote:  [font=Times New Roman][size=medium]So I am browsing through the Auction place. looking at calculator offerings, as one does. I look at a Swiss Micros DM42 listing, the price is okay. and then I look an anything else the seller has on offer. HP 35s for $300? Is this a listing typo?
I just did a search in the E place and $250 is the minimum asking price and NOS is over $400!! Why?!

I sell one. My price will be much much lower. See the "For sale" area.

[sanchezmikea]

Is there a schematic or has someone "hot wired" the 35s for data imput. Can the keyboard be "hot wired" for data imput EG programming as programmed 35s can get $100 for the service.