43s status

[brouhaha]

(06-24-2014 01:11 PM)Claudio L. Wrote:  However, if your RAM can at least match or exceed the 512 kbytes of the 50g and 2 MBytes of flash, we should be able to make it run without too many changes in the code. Then your project would become more like the "universal calculator hardware", and people would be able to run different ROMs according to what they want from the machine.
Knowing the SoC would help make sure even our low-level stuff remains compatible.

It's an Energy Micro EFM32GG380F1024, with 1MiB of flash and 128KiB of RAM. The EFM32GG can support additional external memory, but we don't have enough PCB space for that, and it would significantly increase the power consumption. To the best of my knowledge, there is no SoC with 2MiB of flash and 512KiB of RAM that doesn't draw at least an order of magnitude more power than the EFM32GG, so there is basically no chance that we will switch to something with more memory. Also we're not about to throw away our hard-won design expertise with the EFM32 and start from scratch (again!) with some other SoC. We've already restarted the project several times, and if we keep doing that we'll never ship anything.

The HP-28C clearly had nowhere near enough RAM, but the HP-28S was a pretty usable RPL machine with 128KiB of ROM and 32KiB of RAM. Our hardware has eight times as much flash (vs 28S ROM), and four times as much RAM. Even with the increased memory consumption of 32-bit pointers on native ARM vs. 20-bit on Saturn (or Saturn emulated on ARM), its seems that it should be possible to run RPL on it. However, as I said, RPL isn't our target.

We do expect customers to be interested in at least two different firmware choices for our hardware, Free42 and WP-43s. We also have the HP-41CX microcode running on it, but that doesn't map well to the extended Pioneer keyboard layout.