Re: [stella] 12 chars/line!?

Subject: Re: [stella] 12 chars/line!?
From: emooney@xxxxxxxxxxxxxxxx (Erik Mooney)
Date: Fri, 26 Sep 1997 21:56:08 GMT
>>  	reading the first character (min. 4 cycles)
>> 	reading the second character (min. 4 cycles)
>> 	masking the second character (2 cycles)
>> 	combining the characters (3 cycles)
>> 	writing the combined character (min. 4 cycles)
>> 	adjusting indexes (min. 4 cycles)
>> 	looping (3 cycles)
>If you use two font tables, you can skip the mask.

In that case, it's as simple as LDA character1 / ORA character2 / STA
destination, adjust indexes and loop.

>The BIGGER problem is: how do you *really* display it?  Using two players,
>three copies mode, there are only 2 2/3 CPU cycles between needs to write
>to GRP0 and GRP1 (alternately.)

We've been over this before here... look in the archives for a "48 pixel
highres routine explained" message sometime around April, or if you can't
find it, let me know and I'll email it, or maybe repost it to the list.
You need to have six 16-bit pointers to each player image in RAM... after
that, it's a standard routine with one cycle per line to spare.  It
involves the player vertical delay registers.

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