Hi!

In another topic, i was discussing the idea of a 3d module.
But as for now it lacks a important component, and that is a sort of CRTC (video display generator) that would generate 8 bit color(R 2-bit,G 2-bit,B 2-bit,Luma 2-bit, i suppose this scheme would work) graphics, with the max resolution of 192x256(for now).
I don't really know how pal video is generated, so i don't really know how to make this from scratch.
Could someone strip down some other project that implements color video generation, so it might be adjusted to fit the description.
It would be great if this would fit in a XC9536 cpld, because they are kinda inexpensive. Also it should be similar to the MC6847, continuously loading pixels from video ram, with the fs signal output.
This could be used to develop future projects, also it could be used in other projects(any project where there is a mcu that does some sort of graphic, and renders it).

I also made a c++ program in visual studio that emulates the device described above, it works fine on win xp, but on win7, it displays in super slow motion... Is there a good and simple way to display simple graphics in C(i tied many solutions that Google gave me, but none worked).

Hi Dajgoro

The PACE project has some video controllers in VHDL, including the 6847:
https://svn.pacedev.net/repos/pace/sw/s ... ent/video/

Cheers
Ed

Also, Peter Wendrich has written a version of the VIC-II, 656x for C-64 in VHDL in the Syntiac Pages. Hunt inside the .zip file.

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65Org16:https://github.com/ElEctric-EyE/verilog-6502

But watch for the license... - as far as I read it, it is not what OSF would call open source (IANAL)

André

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Author of the GeckOS multitasking operating system, the usb65 stack, designer of the Micro-PET and many more 6502 content: http://6502.org/users/andre/

Very true! I did not read his license... Bad habit of mine... At least he has posted his work, so others can learn from the code without explicity copying and using it. That attitude I can appreciate!

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65Org16:https://github.com/ElEctric-EyE/verilog-6502

Thanks for the links!

mstram (Mike) maild me this fpga soc system that he found, with an integrated vga controller, link:
http://www.fpgacpu.org/xsoc/

If somebody makes the hardware, and sends me a board, I'll volunteer to write some Verilog for a video generator.

I could build a board, but i currently only have xc9536 cpld, can this cpld be used, or would you need something more powerful(the xc9573?). I aim on cheap components, and some fpga can be really hard to find and expensive(i also like the plcc package, since i can solder the socket on perfboard), i also usually shop on ebay...

Here's a display controller using an XC95108: http://elm-chan.org/works/crtc/report.html

It's probably hopeless to try to fit in a smaller device. And his design even includes an external IC for PAL/NTSC modulation.

Of course, you could use the 65org16 Dev board. It has everything required for video generation, and plenty of room left over in the FPGA to add some 3D functionality.

This is great, but i can't find any XC95108 in plcc on ebay, any other cheap store where i could get one, without getting robbed on shipping prices?

Could this fit in the XC9573 if the resolution is shrunken down to 192*256?

Hard to say, but as that would only save 2 or so macrocells, it's not very likely.

Any suggestions where to find the 95108 in plcc?

I tried to investigate the implementation. The project is described in ABEL HDL (pdf), which needs an older version of the Xilinx tools: perhaps version 10 is the latest which will support it. I had some success using 8.2 command-line tools (with cribs from here) to convert to user-unfriendly vhdl and then synthesising in version 11. It still failed to fit a XC95108-7-PC84 with default tactics or even with adjusted tactics:
Attempting to reduce the input or product term limits seem to lead to an impasse with:

So this design does seem to be right on the limit, if not a little over.

Probably re-writing the ABEL in a modern HDL and studying the implementation would be the thing to do, if it is worth pursuing - or using the supplied JEDEC files if it is good enough as is, which means targeting the exact device.

Cheers
Ed

Nice work. Fitting this in a smaller device is even more impossible than I had guessed.