On Sun, 28 Aug 2016, Isaac M. Bavaresco wrote:

> It is said that (ancient) Microsoft Basic for Z80 is full of such
> "optimizations", where a jump to the middle of a multi-byte instruction
> to achieve a different instruction is used extensively. I think it was
> written in assembly.
>

Bare in mind that the Z80 instruction set is kind of an enhanced 8080=20
instruction set in which many instructions can be used with a prefix to=20
change the source or destination.

e.g.
 	ld A,(HL)	=3D>    7E
 	ld A,(IX+off)	=3D> DD 7E XX (where XX =3D off)
 	ld A,(IY+off)	=3D> FD 7E XX

 	and

 	nop		=3D>    00

Because of this I am much more impressed by the 6800 use of this hack than=
=20
I am of the Z80 use which in my opinion is very much easier to do (think=20
of entry points into a subroutine taking different pointers to a=20
parameter).

Regards
Sergio Masci
--=20
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