[A83] Re: Rotate 16 bits?

To: "Assembly-83 list" <assembly-83@lists.ticalc.org>
Subject: [A83] Re: Rotate 16 bits?
From: "Patai Gergely" <patai_gergely@fastmail.fm>
Date: Sat, 03 May 2003 07:03:51 +0100
In-Reply-To: <Law11-F12Oiz8JDx2I500023356@hotmail.com>
References: <Law11-F12Oiz8JDx2I500023356@hotmail.com>
Reply-To: assembly-83@lists.ticalc.org

> >rr h rr l
> 
> This will not work.  If the MSb of L is 1, then it is rotated into the 
> carry, and then never rotated into H.  That is why the ADC is needed.
> 
>        ; c: %0 H: %10000000 L: %10000000
> rr  h  ; c: %1 H: %00000000 L: %10000000
> rr  L  ; c: %1 H: %00000000 L: %00000001
>        ; should be:
>        ; c: %0 H: %00000001 L: %00000001
> 
ADC? You have to modify the MSB of H, so that will be a SET 7, H in this
case after a conditional jump like in the previous example of leftward
rotation. BTW you are confusing RR with RL.

PG

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References:

[A83] Re: Rotate 16 bits?

From: "Aaron St.John" <aaronstj@hotmail.com>