Re: A83: Assembly commands

To: assembly-83@lists.ticalc.org
Subject: Re: A83: Assembly commands
From: Harper <pez@bellsouth.net>
Date: Sat, 18 Apr 1998 18:43:01 -0400
Delivered-To: assembly-83-outgoing@towerguard.unix.edu.sollentuna.se
Reply-To: assembly-83@lists.ticalc.org


>- -Phelan 'Amen' Wolf
>
>ldir,djnz,sbc,rra,drl, and rr I have no idea.

ldir: Load Increment Repeat (ldir)
	It actually does LDI (load and inc) until BC=0
	lddr works the same way but decrements	

djnz (e): Decrement Jump Not Zero 
	B=B-1 until B=0

sbc (A,s): Subtract with carry (affects carry flag)

rra: Rotate right accumulator

drl: don't know

rr: rotate right n (rr n; opposed to rra, which uses accumulator

Check the Z80 Hardware Reference and Z80 microprocessor Instruction set
summary - at ticalc.org (I think). They define almost all of the Z80 Mnemonics.

Hope this helped.

Marc Harper

Follow-Ups:

Re: A83: Assembly commands

From: jima@tso.cin.ix.net

Re: A83: Assembly commands

From: benjamin99@juno.com (Alan C Johnson)