[cctalk] Z80 vs other microprocessors of the time.

My first exposure to a computer at home was a BBC Micro with 32kB of RAM and 32kB of ROM. Included in this was a 16kB BASIC ROM which was regarded as fast and powerful, featuring 32 bit integer variables, 40 bit floating point variables, variable length strings, structured programming constructs and everything accessed by keyword statements rather than PEEK this and POKE that. This was implemented by a humble 6502 running at (mostly) 2MHz, with one 8 bit arithmetic register, two 8 bit index registers, one 8 bit stack pointer, a 16 bit program counter and a few flag bits. I would have expected that a computers featuring a Z80 with its larger register set, 16 bit arithmetic operations, richer instruction set and general bells and whistles would have been able to produce a much superior implementation in terms of speed or features or both but I never came across one. Why is that? Did the Z80 take more cycles to implement it's more complex instructions? Is this an early example of RISC vs CISC? Regards, Peter Coghlan