critor 发表于 2015-1-2 00:28:16

Casio ES and ES+ ROM images

本帖最后由 critor 于 2015-1-2 18:25 编辑

The HP-SmartCalc 300s and HP-300s+ are clones of Casio ES and ES+ calculators.
The HP-300s+ for example is very similar to the Casio fx-95 ES Plus.

As you probably know, when developping the ES+ calculators, Casio did fix many things in the ES hardware and software, in order to prevent us from upgrading our calculators.

I don't know if this had already been discovered, so I'm posting it anyway.
HP does provide free emulators for both calculators :

And what's interesting, is that there are ROM files coming with them :

The ROM data is stored strangely, with only 4-bits used for each byte. So they are in fact 128KB and not 256KB.
But converting it into a more usual ROM image should be easy.

Studying the HP-300s+ ROM image running on the ePS6800 CPU, should help us figuring out new ways of upgrading our Casio ES+ calculators and clones of such calculators.

Source & download :

chsi 发表于 2015-1-2 11:00:22

The HP SmartCalc series are indeed clones of Casio models, but we believe they most probably have nothing to do with Casio. The ePS6800 (datasheet) is a microcontroller developed by Elan Microelectronics, and in used in many of the counterfeit Casio calculators we have thus far discovered. Casio machines are based on ML610901, a low-power microcontroller customised by OKI for Casio, and its later derivatives.

This can also be seen from the design and manufacturing process of the circuit boards of SmartCalc machines. SmartCalc resembles many counterfeit Casio machines in this respect, and is vastly different from their Casio cousins. The conclusion we could draw from this is that HP didn't design the SmartCalc line -- they are most likely outsourced to some obscure OEM company. Nonetheless it's great to find out what chip the HP SmartCalc series use.

Below are some investigations on the Casio ES series emulators that you may be interested in:

Download link of 82ES emulator (and modification to emulate 991ES):

critor 发表于 2015-1-2 18:45:46

本帖最后由 critor 于 2015-1-2 18:47 编辑

Thank you for your reply and all your informations.

But if CPUs are different, how can Casio and HP calculators be running exactly the same firmware according to the 0xD884 checksum in the diagnostics ?

朔雪X忆 发表于 2015-1-7 11:19:23

critor 发表于 2015-1-2 18:45
Thank you for your reply and all your informations.

But if CPUs are different, how can Casio and...

One possible reason is that there is actually NO check-sum procedure in HP SmartCalc, instead it just DISPLAY the text. It's a quite common design on those Chinese clones with the brand of CASIO, which prevents you from distinguishing them from a true CASIO XD.
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