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ATARI 2600
Posted: Wed Feb 14, 2024 12:42 pm
by schristis
Im an Avid supporter of the X16 project, I bought an X16 and I want to do so much on it.
I don't want to only use it as an Atari 2600, vic-20 or c64
(as a kid I owned all 3 in the 80's, I saved by delivering papers and anything I could do to get these machines)
No-one would use an X16 "only as" an Atari 2600 with the games only 4k each...
But they were such simple games that were very hard to develop to make fun with only a 4k rom cartrige, and I believe it has a place in our retro community....
Given they only had 3 chips,
a cut down version of the 6502( with fewer pins but same chip), the 6532, and the TIA chip (Television interface Adaptor) that did the video and sound.
Just plug a rom cartrige in and it worked! no ram, no rom kernal... no complications...
I think it would be easy for the VERA to be used as the TIA chip....
And being such a simple machine, would'nt it be so easy to experience these games on the X16 with real archetecture?
I just dont think it would take much, but I'm only a novice wanting to learn assemby... but am familiar....
I know this commuinity wants to go forward in development an not back... with alot still to be done... ~!*
But to be open-minded, This little project would mean alot for people in this community, and why not?
Tell me what you think.....
ohh.. This wouldn't be a feature request for the machine itself, but a feature request for being software in downloads...
as maybe an interface to load the 2600 roms...
Re: ATARI 2600
Posted: Wed Feb 14, 2024 11:10 pm
by kelli217
The Atari 2600's custom chips are memory-mapped to entirely different memory locations than the X16 uses.
The VERA is not set up to easily load custom FPGA cores; while it can be done, the intent behind its design is for it to be as static as the VIC-II design is for the Commodore 64, and the only things that have ever been done to it have been to fix problems or add features that work within the current parameters, leaving the main feature set alone. Not to change things to simulate some entirely different graphics architecture. So it isn't 'easy for the VERA to be used as the TIA chip'. None of its control registers are the same, either.
The CPU in the X16 runs at 8MHz, and while it can be jumpered to run at 4 or 2 MHz, none of those are the 1.19 MHz speed of the 6507 in the VCS... (1/3 of the NTSC 3.58 MHz colorburst frequency). As you may know, Atari VCS games are extremely timing-critical, because the CPU essentially draws all the graphics on the screen as the electron beam is scanning, but the VERA uses a different method, having its own video RAM that it uses as the basis for what to draw to the screen. And 8MHz is not sufficiently fast to check every 2600 instruction and turn it into the equivalent X16 address to access and mode to set and bit to write.
tl;dr: the systems are too different, so trying to make one act like the other would not be possible and still maintain performance.
Re: ATARI 2600
Posted: Thu Feb 15, 2024 11:30 am
by schristis
Hi Kelli, I do fear you are correct; Its that I hope for the world of possibilities with these machines, and was probably wishful thinking.
It would be easier to buy a 2600+
needless to say; I am hopeful and excited about future projects like Davids BBS and serial card, and we might use a 65816, and may be able to play something like multiplayer wolfinstien.
But for myself, I believe this machine may be the most forgiving for learning assembly and architecture that I want to learn more. (I dont know that much right now)
Best regards
Shaun
Re: ATARI 2600
Posted: Thu Feb 15, 2024 5:39 pm
by Edmond D
While I enjoyed the 2600 back in the early eighties, the games only hold some nostalgic appeal now for me.
An 2600 emulator sounds interesting, but perhaps not very practical for a system to take an existing cartridge ROM and run it. There are many 6502 based programs for the various platforms; while a C64 may be able to execute the individual instructions in an Apple II program (since it's all 6502 instructions) it may not be able to run the complete program at all. Programming (manly games) on systems sometimes involves cleaver coding "tricks" to get around limitations of the platform.
As Kelli pointed out the hardware compatibility issues would make this request a tough one to implement.
The other item of concern is the licensing of the game; copyrights are important. Some corporations are very protective of their property. Atari may be one of them -
https://atari.com/pages/licensing.
That being said the X16 is so much more capable than a 2600; many free programs available for it are far more superior & enjoyable than what was ever on the 2600. The 2600 bar is very low - ET -
https://en.wikipedia.org/wiki/E.T._the_ ... ideo_game)
I'd suggest starting with with 6502 assembly on the X16 (there are several good threads and resources referenced here in the forums) then take on 2600 programming
https://www.randomterrain.com/atari-260 ... ie-01.html to see some of the programming challenges.
Re: ATARI 2600
Posted: Thu Feb 15, 2024 6:36 pm
by Ser Olmy
schristis wrote: ↑Thu Feb 15, 2024 11:30 am
Hi Kelli, I do fear you are correct; Its that I hope for the world of possibilities with these machines, and was probably wishful thinking.
The X16 is vastly more powerful than the 2600, but uses a similar CPU. I can see why one might think that 2600 software could be modified to run on the X16, or that creating an emulator or compatibility layer could be possible. However, the 2600 is so radically different from any modern system that unless you completely emulate the hardware, a full rewrite of the software is required.
The main stumbling block is the 2600's video circuitry, the TIA. It is not capable of accessing system RAM or cartridge ROM, and generates the entire picture using internal registers that provide a total of about 5 bytes of storage. If that sounds impossible, it's because it essentially is; the only reason you get to see anything resembling an image is that the CPU constantly alters the contents of said registers while the picture is being drawn.
Here's a quite decent YouTube video explaining how this technique, known as "racing the beam," works.
Emulating this would be almost as much of a headache as it was programming the real 2600 back in the day.
Edmond D wrote: ↑Thu Feb 15, 2024 5:39 pm
While I enjoyed the 2600 back in the early eighties, the games only hold some nostalgic appeal now for me.
I never owned a 2600 myself, and my reaction when watching gameplay videos of 2600 games is basically "you played THAT? And enjoyed it?"
I always thought "E.T." on the 2600 looked rubbish. Then I took a closer look at what it actually takes to create a game on that platform, and immediately changed my mind: "E.T." is a programming masterpiece, it's just a shame it's not at all fun to play.
Edit: Mixed up bits and bytes regarding the TIA.
Re: ATARI 2600
Posted: Thu Feb 15, 2024 8:34 pm
by Edmond D
Ser Olmy wrote: ↑Thu Feb 15, 2024 6:36 pm
Edmond D wrote: ↑Thu Feb 15, 2024 5:39 pm
While I enjoyed the 2600 back in the early eighties, the games only hold some nostalgic appeal now for me.
I never owned a 2600 myself, and my reaction when watching gameplay videos of 2600 games is basically "you played THAT? And enjoyed it?"
It was the only console available to play in most stores - Kmart, Woolworths, ect. Arcades existed, but at age 12 they weren't places for young kids, and ate quarters every minute.
My parents got me a VIC-20 and that was a step up, since it was a computer with BASIC and storage, plus cartridges too. That was a step up and it was in the house and free for me to use (until prime time TV.)
Ser Olmy wrote: ↑Thu Feb 15, 2024 6:36 pm
I always thought "E.T." on the 2600 looked rubbish. Then I took a closer look at what it actually takes to create a game on that platform, and immediately changed my mind: "E.T." is a programming masterpiece, it's just a shame it's not at all fun to play.
It wasn't fun at all, and not having access to the manual didn't help. For me, going back to revisit the game on an emulator platform would be the bottom on my list of things to do. I'd rather jump onto an X16 game, or work on doing some programming for my retro hit.
I've not looked at the code to discern if it is a masterpiece, the game was failure for Atari.
Here's a good article worth the time to read beyond reading the Wikipedia page -
https://www.pcworld.com/article/457378/ ... -time.html
Re: ATARI 2600
Posted: Thu Feb 15, 2024 8:43 pm
by Ser Olmy
Edmond D wrote: ↑Thu Feb 15, 2024 8:34 pmI've not looked at the code to discern if it is a masterpiece, the game was failure for Atari.
Usually, you'd need at least 4-6 months to create a decent game on the Atari 2600. The single programmer who was tasked with creating E.T., Howard S. Warshaw, got a little over 4 weeks. The video linked above goes into some detail regarding how parts of "E.T." functioned.
It's a small miracle that he was able to produce anything by that ridiculously close deadline, and the only reason he managed to do it is that he was considered the most accomplished 2600 programmer in existence at the time, having previously created (as the article mentions) two of the very best games ever to appear on the system.
It's a shame his reputation was tarnished by this game. He really should have turned down that particular job offer. "Sorry, Mr Spielberg, but the answer is no."
Re: ATARI 2600
Posted: Sun Apr 14, 2024 9:17 pm
by danboid
schristis wrote: ↑Wed Feb 14, 2024 12:42 pm
Im an Avid supporter of the X16 project, I bought an X16 and I want to do so much on it.
I don't want to only use it as an Atari 2600, vic-20 or c64
(as a kid I owned all 3 in the 80's, I saved by delivering papers and anything I could do to get these machines)
No-one would use an X16 "only as" an Atari 2600 with the games only 4k each...
But they were such simple games that were very hard to develop to make fun with only a 4k rom cartrige, and I believe it has a place in our retro community....
Given they only had 3 chips,
a cut down version of the 6502( with fewer pins but same chip), the 6532, and the TIA chip (Television interface Adaptor) that did the video and sound.
Just plug a rom cartrige in and it worked! no ram, no rom kernal... no complications...
I think it would be easy for the VERA to be used as the TIA chip....
And being such a simple machine, would'nt it be so easy to experience these games on the X16 with real archetecture?
I just dont think it would take much, but I'm only a novice wanting to learn assemby... but am familiar....
I know this commuinity wants to go forward in development an not back... with alot still to be done... ~!*
But to be open-minded, This little project would mean alot for people in this community, and why not?
Tell me what you think.....
ohh.. This wouldn't be a feature request for the machine itself, but a feature request for being software in downloads...
as maybe an interface to load the 2600 roms...
Hi schristis
If its specifically the Atari 2600 you want to learn with (ouch! That's hardcore) then you can just run the stella emulator on a RPi or whatever your fave SBC or PC like plaform is.
However, if you want a minimal games console thats very easy to build, hack and develop for (in C or assembly) then you should check out the Uzebox. You can build one yourself for about $50, all you need is a soldering iron and a few hours. If you have a SCART TV then you can build the even more minimal Uzebox Omega which only uses one chip.
The Uzebox has been my introduction to C programming, electronics and 3D printing. It has a very friendly forum that are more than willing to help beginners. Its my fave 8 bit platform now, I love the simplicity of it. I'd argue its the best educational platform for that reason.