Threaded Mode | Linear Mode

Waon Shinyoe · (This post was last modified: 08-14-2014 04:11 AM by Waon Shinyoe.)

Hey I just discovered the extremely cheap model on sale in China!

The price is 70 RMB without link cable, or a little bit more than 10 USD. And if you buy 1k, the price can go as low as 45 RMB, or about 7 USD!

Since the 39gs has the ARM9 core from SAMSUNG and there are many socket on the main board, I think it's a nice choice for a rebuilding firmware project, just like the WP-34S project! (Yeah our ArithMax team is considering about developing firmware for it.)

So does anyone have interest in 39gs? Or is it possible to hack the 39gs and using a third-party firmware?

我是爱hl的孩子 · 08-17-2014, 12:36 AM

In fact,I'm a chinese middle school student,I'm using hp 39gs.It is a cheap but Entry level graphing calculator.So if u want to learn hp programming,or hack a calculator,hp49 series are more suitable for ya.(or prime,but there r General Forum)LOL

Claudio L. · 08-17-2014, 12:51 AM

(08-13-2014 04:38 AM)Waon Shinyoe Wrote: Hey I just discovered the extremely cheap model on sale in China!

The price is 70 RMB without link cable, or a little bit more than 10 USD. And if you buy 1k, the price can go as low as 45 RMB, or about 7 USD!

Since the 39gs has the ARM9 core from SAMSUNG and there are many socket on the main board, I think it's a nice choice for a rebuilding firmware project, just like the WP-34S project! (Yeah our ArithMax team is considering about developing firmware for it.)

So does anyone have interest in 39gs? Or is it possible to hack the 39gs and using a third-party firmware?

Yes it is possible.
Hardware-wise it's very similar to the 50g, but with half the ram, half the flash, smaller screen and no SD card.
Other than that, anything written for the 50g can be used on the 39. Older versions of hpgcc used to run on the 39, but later we dropped the target due to limited number of people interested, and limited RAM and ROM space.
The rom update procedure is the same as the 50g, if I'm not mistaken, with no protection at all for modified rom updates, so you can flash arbitrary rom images.

Best of luck,
Claudio

Paul Dale · 08-17-2014, 12:57 AM

(08-13-2014 04:38 AM)Waon Shinyoe Wrote: The price is 70 RMB without link cable, or a little bit more than 10 USD. And if you buy 1k, the price can go as low as 45 RMB, or about 7 USD!

That is insanely cheap. Almost tempted to have a go at firmware for it Smile

- Pauli

d b · 08-17-2014, 03:17 AM

(08-17-2014 12:57 AM)Paul Dale Wrote:
(08-13-2014 04:38 AM)Waon Shinyoe Wrote: The price is 70 RMB without link cable, or a little bit more than 10 USD. And if you buy 1k, the price can go as low as 45 RMB, or about 7 USD!

That is insanely cheap. Almost tempted to have a go at firmware for it

- Pauli

Pauli, how tempted?
three things:
1: crowd sourcing
2: Dave speaks Chinese (but he's very busy right now)
3: I'll contribute and/or beta test, and/or buy two

Paul Dale · 08-17-2014, 03:50 AM

(08-17-2014 03:17 AM)Den Belillo (Martinez Ca.) Wrote: Pauli, how tempted?

Probably not tempted enough. I'm not sure I want to dedicate the next couple of years of my spare time to another calculator project Smile

Quote:1: crowd sourcing
2: Dave speaks Chinese (but he's very busy right now)
3: I'll contribute and/or beta test, and/or buy two

Unfortunately, I can see no way a repurposing project would be commercially viable, the 34S certainly hasn't been.

I also can't imagine crowd sourcing funds would be anything like enough to let me take time off of work to do a project quickly Sad

- Pauli

d b · 08-17-2014, 05:19 AM

(08-17-2014 03:50 AM)Paul Dale Wrote:
(08-17-2014 03:17 AM)Den Belillo (Martinez Ca.) Wrote: Pauli, how tempted?

Probably not tempted enough. I'm not sure I want to dedicate the next couple of years of my spare time to another calculator project

Quote:1: crowd sourcing
2: Dave speaks Chinese (but he's very busy right now)
3: I'll contribute and/or beta test, and/or buy two

Unfortunately, I can see no way a repurposing project would be commercially viable, the 34S certainly hasn't been.

I also can't imagine crowd sourcing funds would be anything like enough to let me take time off of work to do a project quickly

- Pauli

i think that a lot of crowd sourcing projects are like that. it was worth doing and way cool. They paid for themselves, except for all that free time the makers gave away.

Paul Dale · 08-17-2014, 07:41 AM

(08-17-2014 05:19 AM)Den Belillo (Martinez Ca.) Wrote: They paid for themselves, except for all that free time the makers gave away.

Therein lies the difficulty. I'm not sure I'm ready to dedicate several years of my free time to another calculator implementation at the moment. The job market here is dreadful at present and my children are more demanding of my time and money than ever before. In a few years, this will change I expect.

On a very positive and complete calculator-unrelated note, my younger daughter is competing for Australia at the archery World Field Championships in Zagreb this coming week Smile

Unfortunately, she wanted mum with her not dad, otherwise I'd have jumped across to the black forest to meet my 34S conspirators in person for the first time.

- Pauli

walter b · 08-17-2014, 09:36 AM

(08-17-2014 07:41 AM)Paul Dale Wrote: ... otherwise I'd have jumped across to the black forest to meet my 34S conspirators in person for the first time.

Oh, that's a pity. But I'd have to had to recommend taking a look at the target map - although we're a small country in comparison the black forest is quite distant from the Taunus. Wink

But if your daughter's in Zagreb she can't tell you. Good luck to her.

d:-)

Massimo Gnerucci · 08-17-2014, 09:44 AM

(08-17-2014 07:41 AM)Paul Dale Wrote: The job market here is dreadful at present

Here, there and (almost) everywhere... Sad

(08-17-2014 07:41 AM)Paul Dale Wrote: On a very positive and complete calculator-unrelated note, my younger daughter is competing for Australia at the archery

Congrats, and my best wishes!

walter b · 08-17-2014, 10:13 AM

Waon, ni hao!

Is that model you've discovered the same size as the 39gs? Could you show a picture? (I think I've asked that before but can't find it anywhere, apologize for a possible repetition.)

d:-)

walter b · 08-18-2014, 11:07 AM

If you're looking for people and projects needing crowd sourcing, I'd suggest you care of Eric and Richard. Maybe I'm wrong but I have a strong feeling that the world won't get a 43S otherwise. Just a proposal, of course (since there are enough battleships present already, I don't see a pressing need for hacking a 39gs).

d:-)

Paul Dale · 08-18-2014, 11:35 AM

(08-17-2014 09:36 AM)walter b Wrote: although we're a small country in comparison the black forest is quite distant from the Taunus.

Small isn't a comparison, sorry. I've driven the equivalent of London to Athens several times to visit other state capital cities here. We're almost a thousand kilometers from the next reasonably large city.

Even so, I'd hire a car and risk the drive just to see you two. Anything under a fiteen hundred kilometers is a day's drive here even if it is on the wrong side of the road Smile

Plus, I'm pretty sure I'd be able to find a lift from Frankfurt to you if I really needed one Big Grin

Still, I haven't had the chance to go to Croatia which is a real pity Sad

- Pauli

walter b · 08-18-2014, 12:01 PM

(08-18-2014 11:35 AM)Paul Dale Wrote: ... I'm pretty sure I'd be able to find a lift from Frankfurt to you if I really needed one

Just give me a call and I'll try to pick you up in FRA (as long as it doesn't interfere with my working hours). But, alas, it's all hypothetical ...

d:-)

Waon Shinyoe · 08-19-2014, 07:25 AM

(08-17-2014 10:13 AM)walter b Wrote: Waon, ni hao!

Is that model you've discovered the same size as the 39gs? Could you show a picture? (I think I've asked that before but can't find it anywhere, apologize for a possible repetition.)

d:-)

Hi Walter,
I'm sure it's 39gs because some of the members of the Chinese community has already bought it and tested it.

Link:
http://item.taobao.com/item.htm?spm=a230...s=1#detail
http://item.taobao.com/item.htm?spm=a230...s=1#detail

walter b · 08-19-2014, 07:31 AM

Waon, xiè xiè ni(3) - so it's a clone of the 39gs in almost every aspect. Too large for my interest. May be interesting for others.

d:-/

Paul Dale · 08-19-2014, 07:34 AM

(08-18-2014 12:01 PM)walter b Wrote: But, alas, it's all hypothetical ...

This time

- Pauli

Waon Shinyoe · 08-19-2014, 08:34 AM

(08-19-2014 07:31 AM)walter b Wrote: Waon, xiè xiè ni(3) - so it's a clone of the 39gs in almost every aspect. Too large for my interest. May be interesting for others.

d

Hmm that's not a clone! But 39gs ITSELF! The hardware is confirmed the same. And we are just trying to flash a third-party firmware.
Thanks for all the enthusiastic guys and reply!

Claudio L. · 08-19-2014, 12:36 PM

(08-19-2014 08:34 AM)Waon Shinyoe Wrote:
(08-19-2014 07:31 AM)walter b Wrote: Waon, xiè xiè ni(3) - so it's a clone of the 39gs in almost every aspect. Too large for my interest. May be interesting for others.

d

Hmm that's not a clone! But 39gs ITSELF! The hardware is confirmed the same. And we are just trying to flash a third-party firmware.
Thanks for all the enthusiastic guys and reply!

Here's an old page where there's a memory map of how things are in a hp49G+, the memory map would be almost identical on the 39gs.

http://lebonpoint.chez-alice.fr/hp49gp/reverse.htm

Basically, your firmware image will be loaded at address 0x4000, and the bootloader will jump into your code at 0x4018.
Exception handlers are pointing to 0x0 (in ROM), but the ROM relocates them to RAM (0x08000000), it's all handled transparently, so for all you care, just set your exception handlers in RAM and set your entry point at 0x4018, then you can do whatever you want.

Claudio