Re: 6502 illegal opcodes questions

[Bruce Tomlin <bruce#fanboy.net@127.0.0.1>]

In article <qhwtch92jx.fsf@ruckus.brouhaha.com>,
 Eric Smith <eric@brouhaha.com> wrote:

> "John Selck" <gpjiweg@t-online.de> writes:
> > And then we would have ended up like the Z80: That a copy loop is faster
> > than the actual block copy instruction :D
> 
> Can you cite an example?  The block move instructions on the Z80 are
> actually fairly efficient.  They use three memory cycles to move a byte,
> vs. the theoretical minimum of two.  Doing a block copy via a software
> loop is going to require at least five memory cycles per byte moved, and
> probably more.

That was my understanding as well, having actually done machine language 
on a Z-80 (typing in hex like ED B0 because it was faster than using an 
assembler).