Jump to content
bhall408

Emulators with F18a Support?

Recommended Posts

On 5/29/2020 at 2:46 AM, Pixelboy said:

:? 

If you assume double size sprites, then yes, you can define 64 sprite patterns. But we were talking about what the F18A adds to the system - that count is from the original 9918 and doesn't change on the F18A. ;)

 

Share this post


Link to post
Share on other sites
1 hour ago, Tursi said:

If you assume double size sprites, then yes, you can define 64 sprite patterns. But we were talking about what the F18A adds to the system - that count is from the original 9918 and doesn't change on the F18A. ;)

 

You're mixing up the pattern and display tables.

 

There's room reserved for 256 sprite patterns in VRAM on an unmodded ColecoVision. Divide that number by 4 because each 16x16 sprite requires 4 tile patterns, and you get 64 sprite patterns.

 

The sprite attribute table can only display up to 32 of those 64 sprite patterns on the TV screen.

 

Some people keep confusing the two concepts. The hardware can only display up to 32 sprites on the screen. But in VRAM, you can define 64 sprite patterns and those 32 displayable sprites can use any of those 64 patterns.

 

Uninformed people come here looking for information, and this information should be clear. I recall a video I saw on YouTube recently where the guy explained that the ColecoVision could display 16 of 256 possible colors, which is absolutely not true. The ColecoVision is limited to 15 colors plus one "background color" that can be set to any of the actual 15 colors. It's very easy for noobs to get their facts wrong because they think all the old consoles and computers had very similar graphic chips, which was far from being the case.

 

Share this post


Link to post
Share on other sites
7 hours ago, Pixelboy said:

You're mixing up the pattern and display tables.

 

There's room reserved for 256 sprite patterns in VRAM on an unmodded ColecoVision. Divide that number by 4 because each 16x16 sprite requires 4 tile patterns, and you get 64 sprite patterns.

 

The sprite attribute table can only display up to 32 of those 64 sprite patterns on the TV screen.

 

Some people keep confusing the two concepts. The hardware can only display up to 32 sprites on the screen. But in VRAM, you can define 64 sprite patterns and those 32 displayable sprites can use any of those 64 patterns.

 

Uninformed people come here looking for information, and this information should be clear. I recall a video I saw on YouTube recently where the guy explained that the ColecoVision could display 16 of 256 possible colors, which is absolutely not true. The ColecoVision is limited to 15 colors plus one "background color" that can be set to any of the actual 15 colors. It's very easy for noobs to get their facts wrong because they think all the old consoles and computers had very similar graphic chips, which was far from being the case.

 

No, I'm not, but the more you try and get me to explain myself, the deeper you drag me. ;)

 

A "double-size" sprite is a 16x16 pixel sprite - that's what "double-size" means. It's not a term I made up that you can just discard to tell me why I'm wrong. ;) 

 

I've been programming this hardware for 35 years, I'm not confused about how it works. My statement was that in this aspect, the F18A is the SAME as the 9918.

 

Share this post


Link to post
Share on other sites
On 5/29/2020 at 10:31 AM, mumbai said:

I do believe Antarctic Adventure (at the least) is problematic w/ F18a present.

I wasn't able to reproduce that... If anyone has more details/what to look for, I'd appreciate it.

 

Share this post


Link to post
Share on other sites
On 5/29/2020 at 10:35 AM, Ikrananka said:

Also, the homebrew game QBIQS (published by Team Pixelboy) uses sprite masking and so is best with the 4 sprites per line limit.

Is the author on AtariAge? If so, would appreciate making a connection to try it out...

Share this post


Link to post
Share on other sites
41 minutes ago, bhall408 said:

I wasn't able to reproduce that... If anyone has more details/what to look for, I'd appreciate it.

 

It occurs when the penguin falls into a crevasse.  If the F18A sprite limit is set to 32 then you can still see all of the penguin's body despite the fact that the bottom half should be hidden inside the crevasse.

  • Like 1

Share this post


Link to post
Share on other sites
44 minutes ago, bhall408 said:

Is the author on AtariAge? If so, would appreciate making a connection to try it out...

The author of the game is here on AA with the name SapphiRe.  In this post he describes his use of sprite masking and the issue with the F18A set to 32 sprites.

 

 

 

  • Thanks 1

Share this post


Link to post
Share on other sites
21 hours ago, Ikrananka said:

It occurs when the penguin falls into a crevasse.  If the F18A sprite limit is set to 32 then you can still see all of the penguin's body despite the fact that the bottom half should be hidden inside the crevasse.

Thanks -- knowing that, I was able to reproduce it. Not the end of the world, but it does suggest we should have a black list of games where the limit should remain 4... Better to track the ones where it should be off, since there are so few of them...

 

 

Screenshot_20200531-131717.png

Share this post


Link to post
Share on other sites
22 hours ago, Ikrananka said:

The author of the game is here on AA with the name SapphiRe.  In this post he describes his use of sprite masking and the issue with the F18A set to 32 sprites.

 

If the game has only ever been released on cart, then I think there is no point to worry about it for Argon.

 

If it has been available or sold in ROM format (and I am pretty sure the answer to that is no), then I'm happy to add it to a table we keep so that 4 sprite limit would be in place for that game (same as we'll flag Antarctic Adventure). I just need a hash value (don't need the game/file itself)

 

@SapphiRe If you think this is worth doing, just PM me so we can work out best way to work that out. If not, no problem. Happy to set you up with an alpha.

Share this post


Link to post
Share on other sites
1 hour ago, bhall408 said:

If the game has only ever been released on cart, then I think there is no point to worry about it for Argon.

 

If it has been available or sold in ROM format (and I am pretty sure the answer to that is no), then I'm happy to add it to a table we keep so that 4 sprite limit would be in place for that game (same as we'll flag Antarctic Adventure). I just need a hash value (don't need the game/file itself)

Quite a few people dump the ROM from the carts they buy for their personal use in emulators (myself included).  If you need a hash for the ROM then just let me know which type of hash you need and I can let you know what it is.

Share this post


Link to post
Share on other sites
15 minutes ago, Ikrananka said:

Quite a few people dump the ROM from the carts they buy for their personal use in emulators (myself included).  If you need a hash for the ROM then just let me know which type of hash you need and I can let you know what it is.

Direct Message sent.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...