newRPL - Updated to build 1510 [official build remains at 1487]

[goosnarrggh]

(05-27-2022 05:59 AM)Claudio L. Wrote:  

(05-06-2022 06:59 PM)Kevin Ouellet Wrote:  Thanks for all the information everyone! I guess I was misled by the doc about the 39g+ supporting NewRPL, but given how uncommon this calculator seems to be and how fast it got replaced by the 39gs I can totally understand that the doc was written this way. I got my 39g+ on Ebay for $7 a few weeks ago and my 39gs as well for $20 (although the 39g+ costed $20 shipping) and I find myself using the former more often than the 39gs but I guess I'll use the 39gs instead for NewRPL.

As far as I understand, the only difference between the 39g+ and 39gs is that it has 4 batteries, and a keyboard that doesn't break. Same as the difference between the 49g+ and the 50g.

Perhaps those were the physical differences, but it would appear that there may have been some differences in the firmware which could negate some of the similarities. It's possible that the chip which holds the firmware could be physically flash rather than mask ROM, but I don't think the firmware provided any way to modify its contents.

For example, the boot/sefltest mode in the 39g+ I have in front of me only has one menu option,

Code:

1. SELFTEST

.

Perhaps it might be possible to modify the boot code and introduce a flash upgrade feature, but it might need to be accessed via JTAG or some other equivalent low-level interface. I haven't been brave enough to try to open up the case to see what interfaces might exist to even attempt to go down that road.

EDIT: Similarly, I also have two first-release HP48gii units (3-cell battery compartment), and they also don't offer a flash upgrade option in their boot/self-test mode.