Re: A83: Atten: James Matthews

Re: A83: Atten: James Matthews

• To: Bruce Link <assembly-83@lists.ticalc.org>
• Subject: Re: A83: Atten: James Matthews
• From: Linus Akesson <lairfight@softhome.net>
• Date: Thu, 08 Oct 1998 22:54:36 +0100
• Delivered-To: assembly-83-outgoing@towerguard.unix.edu.sollentuna.se
• In-Reply-To: <199810080227.VAA00015@access.mbnet.mb.ca>
• Reply-To: assembly-83@lists.ticalc.org

Now let's get this straight once and for all:

!--->>> *The cp instruction performs a temporary subtraction* <<<---!

And negative numbers are expressed like this; -1 is what you get if you
subtract 1 from zero (ffh), -2 is what you get if you subtract 2 from zero
(feh) and so on.

Linus

On 08-Oct-98, Bruce Link wrote:

>I read your little tutorial on jp jr and call... very enlightening.. except
>for one thing..
>the occurrences used with jp, mainly m.

>Minus: meaning (I assume) less than zero. Not less the compared number.
>But since the accumulator is only 8 bit.. how can you have a negative number?
>Or is it simply a case of it being less than?

>I have also been using the 'carry' command after jump and have found that
>it works well as a 'less than' statement conversely I have been increasing
>the accumulator and using the nc statement as a 'greater than' statement
>with a good deal of success. Any comments on these practices?

>Thanx
>Bruce

• A83: Atten: James Matthews
• From: Bruce Link <bjelink@yahoo.com>

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