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Electronics => Projects, Designs, and Technical Stuff => Topic started by: sirus20x6 on September 21, 2012, 02:16:09 am

Title: ARM CPU + z80 GPUS?
Post by: sirus20x6 on September 21, 2012, 02:16:09 am

So I've never ever done anything like this but I have this mad idea


(http://i.imgur.com/uqPUX.png) (http://i.imgur.com/uqPUX.png)

and here is my progress


Front:

(http://i.imgur.com/tUmDb.jpg) (http://i.imgur.com/tUmDb.jpg)


Back:

(http://i.imgur.com/CIftJ.jpg) (http://i.imgur.com/CIftJ.jpg)

Is this sane/doable? do you think I'll need any glue logic? I picked up a couple of ATF22V10C chips. which is atmels version of a gal22v10 but I don't think I'll have to use them.

I've got to figure out chip select on the z80 side the video dac I have is a ADV7125 and that feeds a ad723aruz which is what the uzebox uses.

Title: Re: ARM CPU + z80 GPUS?
Post by: poptones on September 21, 2012, 02:26:18 am

Why?

Title: Re: ARM CPU + z80 GPUS?
Post by: sirus20x6 on September 21, 2012, 02:34:55 am

for fun? and to learn ARM

Title: Re: ARM CPU + z80 GPUS?
Post by: Zad on September 21, 2012, 02:44:46 am

Well it will be an adventure certainly! Although ARMs are plenty fast enough to bit-bang VGA and analogue video through simple resistive DACs.

Title: Re: ARM CPU + z80 GPUS?
Post by: sirus20x6 on September 21, 2012, 03:00:59 am

well i already have a 24bit dac and the video encoder chip. this will get me composite and s-video out.

Anyone have an idea of how to clock all these chips? my ad723 requires 3.58mhz (NTSC frame burst) so the z80s will run at 6 times that for 21.48 and the ARM chip is 50mhz so 14 times 3.58mhz will get me 50.12mhz. I hear these shift registers top out at 25mhz which is perfect.