Layer precedence (register $15) not working

Do you live and breathe hexadecimal? Do you like speaking to hardware directly?

Moderator: Programming Moderators

Post Reply
User avatar
SevenFFF
Posts: 221
Joined: Mon Jun 05, 2017 5:30 pm
Location: USA

Layer precedence (register $15) not working

Post by SevenFFF » Thu Mar 01, 2018 3:19 am

Register $15, the sprite control register, is not working for me at all. Whatever value I set here, the order is always Sprites on top, then layer 2, then ULA underneath. And sprites are always enabled, even if I clear bit 0.

I checked the site, wiki and z88dk headers, and they all indicate it should work. Has the register changed? On 0.8b, but it was doing the same thing on 0.8a.

My whole design depends on layer 2 being on top of sprites This should be %0 00 001 1 1 - LSU Over Border Visible - 7, right?
Robin Verhagen-Guest
SevenFFF / Threetwosevensixseven / colonel32
NXtel Spectron 2084blog

User avatar
Timbucus
Posts: 229
Joined: Tue May 30, 2017 7:43 pm

Re: Layer precedence (register $15) not working

Post by Timbucus » Fri Mar 02, 2018 1:33 am

Will ask team to investigate and confirm if this is an issue...

EDIT: Garry cannot reproduce in NextBASIC but, sprites only appear under Layer2 where the transparency colour is. The same applies in the Border, if they are enabled to show in the border then the border colour must also be transparency to show them. Do you have a code sample and steps so we can try and reproduce?

Tim
I'm Infinite Imaginations when not in work... PAWS for thought.

User avatar
SevenFFF
Posts: 221
Joined: Mon Jun 05, 2017 5:30 pm
Location: USA

Re: Layer precedence (register $15) not working

Post by SevenFFF » Fri Mar 02, 2018 3:25 am

Thsnks Tim! I made a code sample and then found that didn’t reproduce it. Grrr, eventually I found al old piece of code that was writing to port 15 to enable sprites, and resetting the layer order.

Good call on the transparent border colour.

Sorry to waste Garry’s time.
Robin Verhagen-Guest
SevenFFF / Threetwosevensixseven / colonel32
NXtel Spectron 2084blog

Post Reply