Re: [stella] yet another Asymmetrical playfield

Subject: Re: [stella] yet another Asymmetrical playfield
From: Glenn Saunders <mos6507@xxxxxxxxxxx>
Date: Sat, 30 Aug 2003 01:57:36 -0700
At 08:59 PM 8/29/2003, you wrote:
I was wondering, why was Glenn so hot to do
reflected assymetrical playfield...

It was easier to encode the playfield bitmap to 4 8-bit wide playfield register writes, leaving a single write to PF2 for both sides of the border.

I really did NOT want to have to deal with that half-byte in the middle of the screen, doing bit masking and having an extra store for the right border.

Obviously it's still a pain dealing with the bit order reversals, which will complicate my tombstone plotting routines.

I know a lot of games manage okay with a non-reflected playfield bitmap, and gain the advantage of looser timing in the middle of the screen, but I think it was a net gain for DD, timingwise, to do it with reflected.

It is still necessary to blank out the playfield every other line to be able to do all the sprite stuff so you can see how cramped the timing is.

Archives (includes files) at
Unsub & more at

Current Thread