[A83] Re: tst + tstio instructions

To: assembly-83@lists.ticalc.org
Subject: [A83] Re: tst + tstio instructions
From: Hyperbyte <hyper@hysoft-automation.com>
Date: Tue, 3 Jul 2001 14:50:18 +0200 (CEST)
In-Reply-To: <000401c103bd$357be9a0$9e9474d5@qxd2j> from "Ronald Teune" at Jul 02, 2001 09:47:26 PM
Reply-To: assembly-83@lists.ticalc.org


> And how about jp m,xxxx ? And what's the use of ld a,a ?
jp if minus (-127<a<0)

ld a,a (and ld b,b c,c d,d ...) is just a result of the way the instructions
are made up, rewad the z80 manual (users guide) from zilog

> RET  C       D8   1 NOP 1    ;ret if carry (whatever it is)
Carry means, addition/subtration/cp went past zero

> RET  M       F8   1 NOP 1    ;?
see jp m,xxxx
> RET  NC      D0   1 NOP 1 ;ret if not carry
true
> RET  NZ      C0   1 NOP 1  ;ret if not zero
true
> RET  P       F0   1 NOP 1    ;?
ret if 0<a<128
> RET  PE      E8   1 NOP 1  ;?
Parity even
> RET  PO      E0   1 NOP 1  ;?
Parity odd
> RET  Z       C8   1 NOP 1   ;ret if zero
> 
> >You probably mean that if it contains a 2 at the end, it's junk to us...
> >
> >Includes OUT0, OTIM* OTDM*, (SLP), [
> >
> >but
> >IND, INDR, INI and INIR don;t have that (yeah, I found more insturctions
> :-)
> >
> >What do they do?
> 
> 
> 
>

References:

[A83] Re: tst + tstio instructions

From: "Ronald Teune" <rtwolf@gmx.net>

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