Emulator vs simulator performance

[J-F Garnier]

(06-05-2020 03:26 PM)David Hayden Wrote:  Also, it's my understanding that the 42s is implemented in SysRPL. That adds another layer of complication and slowdown compared to assembly language. As I recall working with C on a 50g, the speed difference there is something like native C code is about 5x faster than Saturn assembly, which is about 5x faster than SysRPL, which is about 5x faster than User RPL. Those values may vary somewhat, but I do recall specifically that C code is about 100x faster than userRPL on the 50g.

Yes, the 42S is internally using RPL. But Free42 is written in C, not assembly language, so the comparison is fair.
On the other hand, in this particular benchmark, we can expect a significant part of the time is spent in arithmetic operations that are in asm in the HP-42S, not sure in the Intel 35-digit library.

My own Emu71/DOS is largely written in assembly (using Intel x86 BCD support for efficiency - at the cost of minor compatibility issues) but it's a 16-bit DOS application and there is no native HP-71 simulator available for comparison.

J-F