HP40GS vs HP50G

[Han]

Are these machines similar enough to where flashing one with the other's OS would be feasible?

[Marcus von Cube]

(12-11-2015 01:42 PM)Han Wrote:  Are these machines similar enough to where flashing one with the other's OS would be feasible?

Almost. The 40GS has a lesser display (smaller resolution). It might work because the 48GS has the same display and runs the 50G software. You might be able to find one of these.

[Massimo Gnerucci]

(12-11-2015 03:46 PM)Marcus von Cube Wrote:  the 48GS has the same display and runs the 50G software.

Never seen a 48gs.

[Claudio L.]

(12-11-2015 03:46 PM)Marcus von Cube Wrote:  

(12-11-2015 01:42 PM)Han Wrote:  Are these machines similar enough to where flashing one with the other's OS would be feasible?

Almost. The 40GS has a lesser display (smaller resolution). It might work because the 48GS has the same display and runs the 50G software. You might be able to find one of these.

A well known online retailer has them, but $10 more expensive than the 50g...
It's the same processor, emulating the same saturn environment, so it's very likely that roms can be exchanged. The 50g ROM can detect the smaller screen of the 48GII, so it might be able to detect this one too.
However, you have also only 256 kb of ram instead of 512 kb. Assuming it runs the same emulator, you will have only 128 kb for user ram.
The opposite might be more interesting: try the 40gs firmware on a 50g and see if it works.

In any case, half the RAM, no SD card and no infrared for $10 more is not exactly the best deal.

EDIT: HPGCC 1.1 used to run on the 39g and 40g, which were also the same hardware, but non-flashable roms.

[Marcus von Cube]

(12-11-2015 04:58 PM)Massimo Gnerucci Wrote:  

(12-11-2015 03:46 PM)Marcus von Cube Wrote:  the 48GS has the same display and runs the 50G software.

Never seen a 48gs.

I think it's named 48gII, not 48gs. I have to find mine and have a look.

[Massimo Gnerucci]

(12-11-2015 06:42 PM)Marcus von Cube Wrote:  

(12-11-2015 04:58 PM)Massimo Gnerucci Wrote:  Never seen a 48gs.

I think it's named 48gII, not 48gs. I have to find mine and have a look.

Ah, alright then. I thought of a never released model (to go hunting for)... :)

[Han]

Thanks everyone for the replies. I had hoped to try out newRPL on one of these, but there's no point if it is more expensive for less hardware.

[Claudio L.]

(12-11-2015 09:08 PM)Han Wrote:  Thanks everyone for the replies. I had hoped to try out newRPL on one of these, but there's no point if it is more expensive for less hardware.

Well, you should've started with that!
NewRPL has the RAM size hard-coded, as well as the size of the screen. Changes required would be minimal and in theory it will work perfectly fine on a 40gs, after the proper changes are implemented.
The stock ROM, however, can auto-detect the different models and adapts to the different screen sizes and ram.

[cyrille de brébisson]

Hello,

The 4 calcs, 39, 40, 48 and 50 (ARM based) have virtually the same HW.
The differences lies in the screen size and (but I am not 100% sure) the Ram size.

What I do not remember is if there is a detection mechanism to let the SW detect which of the 4 HW it is running on.

If this is the case, flashing the code from one onto the other will not work.

Cyrille

[Claudio L.]

(12-14-2015 06:12 AM)cyrille de brébisson Wrote:  Hello,

The 4 calcs, 39, 40, 48 and 50 (ARM based) have virtually the same HW.
The differences lies in the screen size and (but I am not 100% sure) the Ram size.

What I do not remember is if there is a detection mechanism to let the SW detect which of the 4 HW it is running on.

If this is the case, flashing the code from one onto the other will not work.

Cyrille

I vaguely remember Saturn assembler pseudo-opcodes like ISBIGAPPLE? or something like that, used to detect different hardware versions/screen sizes. It could at least detect between 49G+ and regular 49G (large vs small screen).
I don't know if the 39 series had something similar.

[cyrille de brébisson]

Hello,

The question is: ISBIGAPPLE is based on a HW difference or a compile time setting.
I am quite sure that, in the case of the 39/40, there is a HW detection mechanism (to make sure that the CAS can not be SW enabled by changing a flag)...

But that is honnestly all I remember.

Cyrille

[sat1410]

At least one person tried to convert a 39gs to a 48gII, documented in Chinese here. It appears to be a non-trivial effort, especially considering the price for use 49g+/50g units is not significantly higher than the lesser units.

I think there was at least one more topic on a non-English-language forum that described the process in more detail (I recall that there was a photo of the donor 39gs reassembled and identifying as a 48gII onscreen). The author of that article mentioned that the 39gs was quite inexpensive since many were being sold as surplus without without packaging or manuals in China at the time.