Cool two chip games console (non propeller)

Andreas Jakob

Just stumbled about this one :

belogic.com/uzebox/

Looking at the screenshots you could think this is made with
a propeller. But its an AVR ATMega644 8 bit controller !
256 colors onscreen and 4 channel sound, amazing.

cgracey

That is cool! They are doing a lot with a little there.

From what I gathered, it uses an 8-bit port to generate 3:3:2 (R:G:B) color data at the pixel rate, which feeds an RGB-to-NTSC converter chip. What I do not understand (because I don't know the ATMega architecture) is how the chip outputs random 8-bit data so quickly. There must be some hardware mechanism for performing memory lookups and outputting the byte result to pins.

What they did here was design an interrupt routine to handle all the sound and video synthesis, along with joystick reading, so that a single-threaded C program could provide the complete personality of the video game. That's pretty neat. The ROM of that chip is 64KB, while the RAM is 4KB.

I think the Propeller parallel to this is the HYDRA. Hey, Andre? Why not make a 'pico edition' HYDRA kit, like you did for the SX console. You could do it all in ONE chip, not two.

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Chip Gracey
Parallax, Inc.

Rayman

It does make one wish for 2X the program memory of the Prop. 64k is enough to hold a decent photo as we see on that page...

Ale

It runs at 28 MHz that is an overclock ! (from 16 to 28). 240x224 in tiled mode. Those games do not need too much power, I mean tetris and the like. The left scrollers when done with tiles are relatively low consuming.

Coley

Chip Gracey said...

From what I gathered, it uses an 8-bit port to generate 3:3:2 (R:G:B) color data at the pixel rate, which feeds an RGB-to-NTSC converter chip. What I do not understand (because I don't know the ATMega architecture) is how the chip outputs random 8-bit data so quickly. There must be some hardware mechanism for performing memory lookups and outputting the byte result to pins.

It's a hardware SPI shift register, similar in principle to your video serializer.

It's what made ATMega's the best option for video until the mighty Prop came along.

Regards,

Coley

EDIT: Thanks for my spell check Baggers!!!

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PropGFX Forums - The home of the Hybrid Development System and PropGFX Lite

Post Edited (Coley) : 8/26/2008 10:16:28 AM GMT

QuattroRS4

Andreas,
That is pretty cool ..

Regards,
John

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'Necessity is the mother of invention'

Oldbitcollector (Jeff)

This thing popped up from a couple different sites in my Google Reader yesterday.
When I saw it, I said "Oh, a Hydra knock-off" and honestly didn't get excited.

We need to make a bigger deal to those outside of this community when people
make cool and interesting stuff for the Propeller. (IE, Baggers, Cook, etc.)
Seems like I'm always yawning at stuff that is making the front page of Make, or
Hackaday these days because we do this kind of stuff all the time, while the rest
of the world thinks they've just seen the cutting edge.. [noparse]:)[/noparse]

OBC

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waltc

Its no Amiga in terms of sound and graphics but it is impressive that someone was able to do this with just a 8 bitter and on-chip resources.

Kudos to them.

Nor do I see it as a Hydra knockoff. Folks have been making their own retro boxes long before Andre put out a Prop based Hydra.

Spork Frog

Could the AD725 give better color/clarity than the on-board video functions of the Prop?

JT Cook

I have to say that is a pretty nice little design and some really nice looking software! I am always fasinated by DIY video games (which is what drew me into the XGS Pico).

I agree with Chip that a Hydra Pico would be pretty sweet! Make a board with Atari style controllers and audio/video out and bundle with the book for $100-$125 or something.

When I went to visit my parents, I made a Hydra out of a protoboard and·a tupperware container to give to them.

Coley

JTCook said...
I agree with Chip that a Hydra Pico would be pretty sweet! Make a board with Atari style controllers and audio/video out and bundle with the book for $100-$125 or something.

We arleady have a design that would tick all the boxes with the Hybrid II.

On and off I've been working on a surface mount version of the Hybrid that drastically reduces the board size.
My idea for doing this was to make it more cost effective and accessible to new users.

I've been turned on to the advantages of surface mount after my experiences with PropGFX.

I am looking about the same size as a demoboard at the moment.

The only things that I am omitting is the prototyping connector, expansion connector and the RS232 port, the SD Card stays but will be Micro SD.

Oh and it will have FTDI onboard so no more PropPlug either.....

And did I mention it could have PropGFX onboard too?

I'll post more details when I have a decent layout completed.

I'm sure Parallax could manufacture it for a lot less than we could thugh..... <hint, hint>

Regards,

Coley

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PropGFX Forums - The home of the Hybrid Development System and PropGFX Lite

waltc

I'm going to build one since its dirt cheap and easy to do and when Atmel starts selling the Xmega series later this year I'm going to build a Uzebox around it.

Ale

The xmegas pack really nice features. It also has some improvements in execution speed for memory opcodes. I do not know at this point how you program them, i.e. if avrdude and a current programmer will be able to program them.