Boxing Disassembly

[DEBRO]

Hi there,

 

Bob Whitehead has my head spinning. Hopefully this labels correct and makes sense. He got this to fit in 2K of ROM.

 

The assembler reports out 14 bytes of RAM free but there are actually 16 more RAM bytes available because of how the RAM is used.

 

Boxing Disassembly

Edited August 1, 2020 by DEBRO

[+Andrew Davie]

I'm not sure how many people realise the work that goes into this.

Top job, congratulations.

[Kevin McGrath]

Very nice!  Seems like this would be a pretty early six digit kernel?

 

I wish we had a stickied forum post with a library of "snippets" / tricks learned for the 2600 from your awesome disassemblies and home brewers.  Even if it was a sampling of just the different kernels used in the original games, I'd still find that very interesting.

 

And I totally agree with Mr. Davie, the amount of work involved in doing this is very significant.  Especially when you're taking care to be able to create both NTSC and PAL ROMs from the source.  Excellent work!

[+Al_Nafuur]

22 minutes ago, Kevin McGrath said:

I wish we had a stickied forum post with a library of "snippets" / tricks learned for the 2600 from your awesome disassemblies and home brewers.  Even if it was a sampling of just the different kernels used in the original games, I'd still find that very interesting.

How about a tool like Github Gist, BitBucket Snippets or snipplr:
https://gist.github.com/

https://bitbucket.org/snippets
https://snipplr.com/

 

there might be better ones, the most important feature should be the search function..

[Kevin McGrath]

9 minutes ago, Al_Nafuur said:

How about a tool like Github Gist, BitBucket Snippets or snipplr:
https://gist.github.com/

https://bitbucket.org/snippets
https://snipplr.com/

 

there might be better ones, the most important feature should be the search function..

Is there an official Atari Age GitHub portal?  It would be pretty rockin' to have a collection of Gists!

[Kevin McGrath]

On 7/25/2020 at 4:45 AM, DEBRO said:

Hi there,

 

Bob Whitehead has my head spinning. Hopefully this labels correct and makes sense. He got this to fit in 2K of ROM.

 

The assembler reports out 14 bytes of RAM free but there are actually 16 more RAM bytes available because of how the RAM is used.

 

Boxing Disassembly

Small correction... In the "SixDigitDisplayKernel" code, it looks like GRP0/1 is set only four times per scanline, so this would only be a four digit (32 pixels) score kernel, not six digits (48 pixels).  The two stores after the branch look to be used just to clear the sprite pixels for the next section on the screen.

 

It's a lot of fun looking through this old code and trying to learn from the masters, thanks again!

[+Al_Nafuur]

16 minutes ago, Kevin McGrath said:

Is there an official Atari Age GitHub portal?  It would be pretty rockin' to have a collection of Gists!

There are also open source tools like snibox, if self hosting is preferred:
https://github.com/snibox/snibox

demo: https://snibox-demo.herokuapp.com/

[DEBRO]

Hi there,

 

On 7/26/2020 at 6:03 PM, Kevin McGrath said:

Small correction... In the "SixDigitDisplayKernel" code, it looks like GRP0/1 is set only four times per scanline, so this would only be a four digit (32 pixels) score kernel, not six digits (48 pixels).  The two stores after the branch look to be used just to clear the sprite pixels for the next section on the screen.

You are correct. That label is a generic label I tend to use. I can change it to be more clear that it is not a six digit display kernel.

[DEBRO]

Hi Andrew,

 

On 7/25/2020 at 9:10 AM, Andrew Davie said:

I'm not sure how many people realise the work that goes into this.

Top job, congratulations.

Thank you. That means a lot. I do this as a pastime. I hope they make sense and hopefully I get close to the original author’s vision. These can’t replace original source code with comments.