The Amstrad Plus ASIC improved a lot of the old CPC's capability.
Yet this was a bit flawed.
*Despite removing some tasks from the CPU ([[Z80]]), ASIC registers are mapped onto memory from #4000 to #7FFF range prior to other type of memory (RAM or ROM). That means this memory range is not accessible when ASIC registers are paged.
*PPI emulation is not correct as the original 8255 does not need validation. On ASIC emulation, this validation is needed so some programs written for "old CPCs" will not be able to get keyboard state.