Re: A86: That crazy IX register

To: assembly-86@lists.ticalc.org
Subject: Re: A86: That crazy IX register
From: assets <assets@eden.rutgers.edu>
Date: Fri, 11 Sep 1998 21:04:17 -0400
Delivered-To: assembly-86-outgoing@towerguard.unix.edu.sollentuna.se
Organization: Rutgers University
References: <004801bddde6$8034c340$61b47180@eniac.dynamic.rpi.edu>
Reply-To: assembly-86@lists.ticalc.org




Stephen Horne wrote:

> Awesome.. thanks! A little inefficient considering that extra byte, but
> maybe its better than pop'ing and push'ing junk around, huh?

:-)It's usually better to use HL, but if you must ...

> _________________________________________________
> >It can be used the same way as HL & can index in addition to that (it can
> >address a byte up to a distance of 128 bytes before it and 127 after it --
> <ld
> >(ix-7),a>, for example).  You can use the high and low registers of IX, but
> not
> >with any innate instructions.  The high register of the IX pair is called
> IXH
> >and the low register of IX is called IXL.  If you use TASM to compile you
> can
> >edit the file TASM80.tab to include the "undocumented" opcodes, if you
> don't
> >use TASM, you will have to be content with inserting the opcodes into your
> >source w/ .dbs.For information on the undocumented opcodes, go to:
> > http://www.geocities.com/SiliconValley/Peaks/3938/z80undoc.htm
> >
> >The new opcodes for IX and IY are basicly the opcodes for instructions
> >employing H or L, but with $dd (for IX) or a $fd (for IY) added before it.
> >Example:
> >
> > and l        ;opcode: $a5
> > and ixl     ;opcode: $dda5
> >
> >>
> >>

References:

Re: A86: That crazy IX register

From: "Stephen Horne" <HorneS@rpi.edu>

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