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foft

5200 in FPGA?

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I am building an Atari XL in VHDL - which currently runs on the Altera DE1. I am tempted to also build a 5200, since I understand its just a different memory layout of the same custom chips.

 

Is anyone interested in trying/testing this? + perhaps someone into electronics who fancies connecting a real controller?

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Yep, round about that. It can run on smaller FPGAs but this is nice for development.

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It should be possible to port to the Chameleon without many issues.

 

For now I'm targeting:

DE1

Sockit

Replay

 

Soooo anyone interested in a 5200 or not?

Edited by foft

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Warning: Stupid question ahead...

 

 

Would it be possible to connect a cart port to this? I'm not all that familiar with FPGA :(

 

If so, then I'm in! (As long as the price is reasonable)

 

Bob

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I'm working on accessing Atari 800 carts now, expect 5200 ones are similar.

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I'm in.

 

Do I need to buy a DE1 dev board from Terasic or Altera?

 

I alreayd have Quartus II and USB Blaster.

 

Hmm, I wonder what packages the FPGA come in, perhaps I can just make a board for it.

Edited by grips03

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Great. If you already have Quartus and a blaster do you already have a dev board? Which one?

 

Current a800 builds are for DE1. I bought one recently from Digikey. You can also buy from Terasic.

 

Would be nice to design an all-in-one pcb at some point. For now I'm going along the breakout board route.

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Great. If you already have Quartus and a blaster do you already have a dev board? Which one?

 

Current a800 builds are for DE1. I bought one recently from Digikey. You can also buy from Terasic.

 

Would be nice to design an all-in-one pcb at some point. For now I'm going along the breakout board route.

 

so this is the board you have?

http://www.terasic.com.tw/cgi-bin/page/archive.pl?Language=English&CategoryNo=165&No=83

 

I have board for Max 5 and 7000S - CPLDs. Looks like I'm getting an FPGA board :) or making one

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Yes that's the one. It's a nice board to start with. Where are you based? US?

 

If you make one - few things to consider:

I) audio dac

Ii) video dac

iii) ram/rom. I use external for the a800 but for 5200 we only need 2k rom + 16k ram. ie 18 kbytes internal ram will do. It's also good to have extra for debugging.

iv) My design takes about 5000 logic elements on cyclone 2. Good to have extra space to debug.

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Yes that's the one. It's a nice board to start with. Where are you based? US?

 

If you make one - few things to consider:

I) audio dac

Ii) video dac

iii) ram/rom. I use external for the a800 but for 5200 we only need 2k rom + 16k ram. ie 18 kbytes internal ram will do. It's also good to have extra for debugging.

iv) My design takes about 5000 logic elements on cyclone 2. Good to have extra space to debug.

 

 

Hmm 144pin in 20x20 or BGA....

 

I might be buying the dev board. Let me know how close you are and as you get closer I'll pickup a board. My first 5200 should be here to tomorrow. I bought to make a better controller, kind of like what I did on Intellivision.

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Well there are a couple of good 6502 cores. So it's a decent Antic, Pokey and GTIA that matter. It sounds like Kevtris is easily capable of building these. That said, I have already built them and just need to reconnect the custom chips. + finish some Pokey bits needed for the controller.

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Do you have any updates on this project? Just curious :-). BTW, the 5200's controllers were actually analog in nature and sensed by POKEY. Your best bet might be to hack this behavior into your design and test with a simple joystick ... maybe fake out the 5200's keypad with a PS2 keyboard ... just some suggestions :-).

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Well I bought a real 5200 joystick for it:) I already got the Pokey analog inputs working for paddles on the a8.

 

Updates are mostly on the a8 side of the project - for now:)

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Interesting, yes.

 

Have you posted about this on the A8 forum, you'd get plenty of interest.

 

For the computer you could quite easily just get away with fudging the keyscan. Probably not quite the case for 5200 mode.

5200 operates Pokey IIRC with keyscan enabled but debounce not enabled. With the computer the keyboard only works properly with keyscan/debounce both enabled.

 

I've not used a 5200 - no idea if you could fudge the keyscan there. I don't even know if it allows simultaneous key presses (disregarding those buttons which aren't part of the normal matrix).

 

If anything the memory mapping for 5200 should be simpler - Antic is the same, not sure how long GTIA/Pokey have repeated images through the map.

 

Of course the tricky part is cartridges if you're not using the real thing - you'd probably want to have mappers for the popular banking schemes which in both cases would be a bit of work.

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I've made a start on this over the weekend. I've got most things wired up, just need to connect a real controller and sort out cartridge support. Initially just from SD card (+basic types only to start with), though of course a real break out board could be built fairly easily...

 

Quick question though since I don't have a real 5200. Should I get the Atari logo rainbow without a cartridge inserted? Or the 'Insert 5200 cartridge message'? I know I know, its only 2K I can step through it :-) Anyone got a handy commented 5200 os listing?

Edited by foft

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Thanks, its very helpful to know. I popped in the Acid 5200 'cartridge', fingers crossed it all passes first time ;-)

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Not bad for the first successful boot I think:

https://www.youtube.com/watch?feature=player_detailpage&v=8rRlfAr6MuU&list=UU4whFObEsLCccA249BIZMtA

 

Now to load a game ROM and connect my controller... I just hope the controller I imported last year works.

 

Good to see it passed the Acid5200 test. Are you wiring up a 5200 controller to your DE1?

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