Re: [stella] Player data loading...semi newbie

Subject: Re: [stella] Player data loading...semi newbie
From: "B. Watson" <urchlay@xxxxxxxxxxxxxxxx>
Date: Wed, 17 Oct 2001 18:41:42 -0400 (EDT)

On Wed, 17 Oct 2001, Glenn Saunders wrote:

> >.skipDraw:              ;  = 19/12 (or 17/10)
> 
> But how do you handle skipdraw?
> 
> Am I correct in assuming that all sprite frames require a zero line at the 
> top in order to make sure the last write to the sprite clears it out?  If 
> .skipDraw doesn't contain an LDA #0, STA GRP0 then it will continue to hold 
> the last line of graphics until the end of the screen otherwise.
> 

Easiest way of doing this is to make sure the last byte of your player is a
zero... you waste one byte of ROM that way, but you'd waste a lot more bytes
(and cycles) trying to decide whether or not to put a 0 in your kernel.

> Also, is there a build of DASM that allows one to use the mneumonics for the 
> illegal opcodes rather than using the BYTE syntax?

You can always define them as macros... though that won't handle different
addressing modes. When I get home, if I have time, I'll look at the source
for DASM to see how hard it looks like it would be, to add opcodes. This
would be a nice feature to have...

B.




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