Jump to content
glurk

NES -> 8bit Ports?

Recommended Posts

Posted (edited)

"Port must contain core logic (code) of the original game" - not actually true as a empirical definition, all "ports" do not have to or are not able to contain original code, although you would be true to assume the actual logic was ported - yet many arcade ports to 8bit machines were done with no access to the code, just the running game on original hardware - so logic by observation at best.

 

And then there is the additional issue of say a Z80 source game ported to a 6502 system, even with access to source code no direct copy is possible...

 

And even if such source code were available the difference between architecture and timing makes a lot of things not work, logic included - so conversion is a more general term I guess and the terms port, conversion etc are freely interchangeable from a user and developer point of view 🙂

 

          sTeVE

 

P.S. Yes I have done porting and conversions of games....

Edited by Jetboot Jack
  • Thanks 1

Share this post


Link to post
Share on other sites
Posted (edited)

What is interesting about the NES is that it is actually using a 6502 clone running at the same speed as the Atari 8bit. They were able to get away without being sued because they only used the portions of the 6502 that was not copyrighted. In fact, I have read that the source code for Super Mario Bros is available online. Maybe studying this code would give certain insights?

 

 

Edited by scorpio_ny
Grammar
  • Confused 2

Share this post


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

What is interesting about the NES is that it is actually using a 6502 clone running at the same speed as the Atari 8bit. They were able to get away without being sued because they only used the portions of the 6502 that was not copyrighted. In fact, I have read that the source code for Super Mario Bros is available online. Maybe studying this code would give certain insights?

 

 

What?  How could Atari sue somebody for using a MOS 6502?  That's ridiculous.  The 6502 is also the only thing the NES has in common with the Atari besides they both connect to a TV.

  • Haha 1

Share this post


Link to post
Share on other sites

Not sure that he means Atari would sue but rather the holders of the 6502 intellectual property if Nintendo didn't license anything from them in reguard to their 'clone'

Share this post


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

What?  How could Atari sue somebody for using a MOS 6502?  That's ridiculous.  The 6502 is also the only thing the NES has in common with the Atari besides they both connect to a TV.

Where in my post did I say it was Atari who doing was doing the suing?

Share this post


Link to post
Share on other sites
Posted (edited)
2 hours ago, _The Doctor__ said:

Not sure that he means Atari would sue but rather the holders of the 6502 intellectual property if Nintendo didn't license anything from them in reguard to their 'clone'

@_The Doctor__

 

Correct! I never stated in my post that it was Atari who sued them. It was MOS Technologies/Commodore. It is quite interesting story. Here is an article on it in case anyone is interested.

Reverse Engineering and Patent Protection: A Cautionary Tale

Edited by scorpio_ny
  • Like 2
  • Thanks 1

Share this post


Link to post
Share on other sites
10 hours ago, Jetboot Jack said:

And then there is the additional issue of say a Z80 source game ported to a 6502 system, even with access to source code no direct copy is possible...

 

It can be done by hand but it is a very arduous task indeed. 

  • Like 1

Share this post


Link to post
Share on other sites
14 hours ago, scorpio_ny said:

@_The Doctor__

 

Correct! I never stated in my post that it was Atari who sued them. It was MOS Technologies/Commodore. It is quite interesting story. Here is an article on it in case anyone is interested.

Reverse Engineering and Patent Protection: A Cautionary Tale

My bad - I misread your post.  Sorry.

Share this post


Link to post
Share on other sites
32 minutes ago, Stephen said:

My bad - I misread your post.  Sorry.

@Stephen,

 

No worries! 😁 I should have made it more clear too. I can see how it could be implied from the post.

 

  • Thanks 1

Share this post


Link to post
Share on other sites

Nice article, if it weren't for some back and forth it might not have been posted here. I'd say that's the kind of thing our interactions make happen. A tip of the hat to all, and kudos to scorpio_ny for linking it again. :)

Share this post


Link to post
Share on other sites
On 7/21/2021 at 1:44 AM, shoestring said:

It can be done by hand but it is a very arduous task indeed. 

I think tedious and annoying both apply 🙂

 

sTeVE

Share this post


Link to post
Share on other sites

Considering Nintendo's attitude to any sort of clone of SMB, I'd think most programmers would not want the hassle :)

Share this post


Link to post
Share on other sites
Posted (edited)
15 minutes ago, Mclaneinc said:

Considering Nintendo's attitude to any sort of clone of SMB, I'd think most programmers would not want the hassle :)

@Mclaneinc

Very true! I linked this not necessarily for a port SMB. By studying the code, it may be possible to give someone insights on how things were done in that system in relation to the Atari 8 bit.

Edited by scorpio_ny
spelling

Share this post


Link to post
Share on other sites
2 minutes ago, scorpio_ny said:

@Mclaneinc

Very true! I linked this not necessarily for a port SMB. By studying the code, it may be possible to give someone insights on how things were done in that system in relation to the Atari 8 bit.

Yes, I realised as much but just voiced the obvious..

 

As many of us know, just how much hassle a certain set of C64 makers got not so long ago :)

 

Personally I'd love a port and any code that could help is always welcome, I'm just waiting for Rick Dangerous to finally get its release (unless there's been any mishaps) :(

Share this post


Link to post
Share on other sites
Posted (edited)
1 hour ago, scorpio_ny said:

I am not sure if this is helpful, but someone disassembled and posted 6502 source code for the actual NES Super Mario game. I am linking it here to see if this would be of interest to some of the programmers here.

 

A Comprehensive Super Mario Bros. Disassembly

It was already being looked into years ago on these forums; in fact on person did a preliminary version with rudimentary graphics (although he never intended to do a full version).

 

1 hour ago, scorpio_ny said:

Most regulars on here are aware of the C64 port.

 

Edited by MrFish

Share this post


Link to post
Share on other sites
Posted (edited)
4 hours ago, scorpio_ny said:

I am not sure if this is helpful, but someone disassembled and posted 6502 source code for the actual NES Super Mario game. I am linking it here to see if this would be of interest to some of the programmers here.

 

A Comprehensive Super Mario Bros. Disassembly

 

the game engine/logic is not hard - the hard stuff is how to make render having 128 charset, zero hw sprites (because all going to the character+shot) and allocating 32-48 fonts for softsprites the same time. Giana |(SMB similar) has just one 2kb 256 charset and done. 

Edited by solo/ng
typo

Share this post


Link to post
Share on other sites

The simple fact that folks need to understand is that simply because it's a 6502 variant, It's not as simple as that..

 

It's a whole new machine with different display and graphical  demands....It's like making an omelette in a microwave vs a pan, same idea, different hardware approach...One does not lend towards the other..

Share this post


Link to post
Share on other sites
12 hours ago, Jetboot Jack said:

I think tedious and annoying both apply 🙂

 

sTeVE

I don't know what is worse, going from Z80 to 6502 or from 6502 to Z80. I've attempted to port a game from the c64 to the Taito L System which uses a z80, it whore me down to the point where I literally suffered from headaches daily and couldn't continue. I realised a straight port wasn't going to work without some massive changes. 6502 and Z80 really don't go hand in hand.

 

My A8 rom diagnostic was initially written for Gyruss, which uses a Z80. Eventually, this was ported to the KONAMI1 ( a custom 6809 with scrambled opcodes ) for games like Track & Field / HyperSports. So the A8 diag routines are based straight off of the 6809 code which was much more straight forward to port than it would have been had I taken the original Z80 code.

  • Like 1

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.
Note: Your post will require moderator approval before it will be visible.

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...