[HP49G] Very poor graphing performances

[Han]

(09-01-2015 03:09 PM)Bruno Wrote:  Thanks for your answer Han,
I think they are at least 2 reasons since the extra time (vs the GX) are too different for the WIREFRAME (47% slower) and PS-CONTOUR (260% slower!!) graphs.
One common reason could be the hardware and/or the operating system implementation difference beetween the HP48GX and the HP49G,
and another reason specific to the PS-CONTOUR graph could be the different implementation of the 'differentiate' function (rewritten for the CAS ?)
used by the PS-CONTOUR algorithm.

I'm amazed that nobody was shocked before.

If I am not mistaken, both the 48G and 49G use the original Saturn chips for the CPU. They have different bankswitching methods. In particular, code residing in covered ROM behave differently. Covered ROM on the 48G series gets copied into RAM before the code is executed (from RAM), whereas on the 49G many flash pointers are run directly from ROM. Only a few ROM routines are copied to RAM and executed from there (the MASD compiler behaves this way).