Re: [stella] Space Savers

Subject: Re: [stella] Space Savers
From: "Edwin Blink" <edwin.blink@xxxxxxx>
Date: Fri, 3 Sep 2004 20:50:48 +0200
Manuel wrote:

>FFFE is the BRK vector as well :-)

Bang ! Somehow I mixed things up and thought BRK used NMI vector.
Thanks for pointing this out to me (Chris too!).

>> STA SWACNT ;Set PORTB to inputs
>> STA SWBCNT ;Set PORTA to inputs
>> ;Just with 4 default variables there is already a byte saving of 3 bytes!

>Save another 6 bytes by removing those two STAs... ;-)

So you don't need to initialize those RIOT ports ever ???

Thomas Wrote:

>...and another byte by removing SEI.

I thought I leave it in just in case.

Chrish Wrote:

>There was a discussion of this a while back.  The 2600 doesn't have an
>interrupt line, and the 6507 doesn't have an interrupt pin, but the silicon
>die has the interrupt.  It's there, it just isn't bonded out to a pin.
>What are the chances that you have a cosmic ray come through and do funny
>things with your 6507?  Not big enough.  But if you're being paranoid...

>I think someone else had a more realistic reason for using the SEI on the
>2600, but I don't remember what it was...

I'm sure the IRQ line is pulled up internally. But I can imagine it could
act weird while
the VCS is powering up.

Back to Thomas:

>BTW: Welcome Edwin! :-)

Thank you for the Welcoming (you and others!). Tried to subscribe earlier
over a month ago but it didn't work then and with the archives not beeing
updated I thought stella was dead. Luckely I found a link somewhere on AA
forum that did work
and found stella alive and kicking :-)


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