Atari 5200 - expansion port?

[+DrVenkman]

9 hours ago, ClausB said:

I once suggested adding SIO but was met with disinterest:

Seems 5200 collectors want the 8-bits' games but not their peripherals.

That was a great thread, thanks. I never understand the attitudes of some dude who comes into a thread like that and says, “The 5200 is just a console - leave it alone!” Fine, no one is going to make you buy a device and plug it into your machine, man. Now be quiet and let the nerds brainstorm ... 

 

I wonder if something like a “lowest common denominator” device could be made today? A boot loader program burned to a simple EPROM cart or a loaded from an AtariMax that then controls data access through a cheap (Arduino? ESP32?-based) device plugged into the Expansion Port? Could open up some interesting areas for coders to explore without requiring major hardware expenditures or anything really invasive. Dunno. I’m just spitballing here. Lord knows I’m just an enthusiastic solder jockey with enough practical electronics knowledge to be dangerous to devices around me.  

[ClausB]

Yes it would be a fun project. My favorite Arduino is the Teensy 3.5 which I made into a 20 kbaud tape sim for the Exidy Sorcerer recently. So it could do SIO easily. But what does it gain for a 5200 user above and beyond a multi-cart, really?

[HDTV1080P]

Maybe a OPCODE style Super Game Module could be made for the ATARI 5200 expansion port. Add some extra ram for improved homebrew games and maybe a new sound chip.  

[leech]

On 7/28/2020 at 5:28 PM, ClausB said:

Yes it would be a fun project. My favorite Arduino is the Teensy 3.5 which I made into a 20 kbaud tape sim for the Exidy Sorcerer recently. So it could do SIO easily. But what does it gain for a 5200 user above and beyond a multi-cart, really?

Was thinking about this... so if you could get an SIO port... or skip that and just hook a Fujinet into it directly?  Couldn't this be a potential way to get 8bit Atari games (mind you 16kb and lack of keyboard aside) to work on the 5200 without requiring specialized ports?

[+x=usr(1536)]

40 minutes ago, leech said:

Was thinking about this... so if you could get an SIO port... or skip that and just hook a Fujinet into it directly?  Couldn't this be a potential way to get 8bit Atari games (mind you 16kb and lack of keyboard aside) to work on the 5200 without requiring specialized ports?

Given that the FujiNet already implements SIO in both hardware and software, it may not even be necessary to hack SIO support into the 5200.  Its USB port is also capable of handling both power and data, so pretty much everything needed for data transfer to and from physical hardware is there along with the potential for attaching a keyboard.

 

As for the 16K limit, I have no good answers for that . It's probably the biggest stumbling block.  Best idea I've come up with is implementing the whole thing on an ARM (or similar) processor on the cartridge itself for the FujiNet side of things, and just using the 5200 for video output and actually running software provided by the FujiNet.  Someone else would need to determine if that's workable or not, though.

[+Allan]

You could upgrade the 5200 to 64K. It would be a pretty simple upgrade.

[ClausB]

9 hours ago, Allan said:

You could upgrade the 5200 to 64K. It would be a pretty simple upgrade.

Yes and no. First, you could fit only 48K into the memory map. Second, there is no signal on the cart port to disable extra RAM when a cart is present.

[Tempest]

Did Atari ever officially announce anything that was supposed to use the 5200 expansion port?  Given that the 5200 was never a big success I'd guess no.

[+x=usr(1536)]

18 minutes ago, Tempest said:

Did Atari ever officially announce anything that was supposed to use the 5200 expansion port?  Given that the 5200 was never a big success I'd guess no.

ISTR that one of the potential peripherals mentioned was a musical keyboard.  Don't believe they ever went much further than that, though.

[ClausB]

5 hours ago, ClausB said:

there is no signal on the cart port to disable extra RAM when a cart is present.

I guess the point of this thread is adding the ability to load RAM-based games, so it doesn't matter.