Yes, because there are some (about 5-10% ) CPC programs, which uses only ROM calls There is nearly no Speccy programs which uses only ROM calls

I see!! I will test ZXM with some "lightweight" favorite games of mine, like "Gangsters!", "Stock Market" and "Dictator", to see what happens... These are mostly BASIC proggies, with little/no code included!
I am not sure if ZXM will load on CPCEmu, though... We will find out in the next days!!
If it loads successfully I will take another photo of the EP running a Spectrum game through CPC emulation!!!

P.S. I also tried to run "20 Commodes" (the VIC emulator) and Videopac emulator on SPEmu, but they didn't load properly... I guess I was lucky with dr.beep's ZX81 emulator, which runs very-very well!!!
Of course your ZX81emu running "natively" on the EP is faster and more compatible, but I did the double emulation just for fun!

There could be more reasons of problem, Spemu checking byte patterns after or before OUT or IN instructions, probably those programs have different byte patterns before or after, other ptoblem is ROM writing, what is used by several Speccy programs ( this can be solved by ROM version of SpEmu), other possible problem is finding things about IM2 interrupt, and probably there is more, just i got to my mind the above mentioned
I got another thing, Nirvana and other programs which are using similar attr refresh method do not work either

Oh, these are details that only programmers can understand, I am just a simple user!!

Opening again this old thread, I'd like to inform anyone interested that Johan "dr beep" Koelman, who is active mostly in the "sinclairzxworld" ZX81 forum has compiled an even more accurate 2.16 version of his emulator on the spectrum and is also working on a ZX80 (!!!) emulator for Spectrum!

I find this impressive and I am looking forward to presenting you here a ZX80 emulated through the fabulous Spemu by geco running on a real EP128!