OpenHandhelds.org

Subject says it all. Anyone working on a minimal library like the GP2X's minimal.c (by Rlyeh)?

just check the topics here, flatmush has started one see his source code

I have seen entry.a and the associated entry.h.

I mean something more like minimal.c.

Anyway, I've got the jz4740 peripheral specification and assuming it's all good/accurate, it's a pretty nice chipset.

I want the ability to:

*Write direct to framebuffer
* Vsync
* Double Buffer
* Set video modes (ie 16bit, 15bit, 8bit palette modes)
* Set palette colors

etc.

It looks like it can do all this (and more!)

I'll see if I can write my own minimal.c

Using Astro Lander source from flatmush you already have a good library that can do what you want
except VSync which is not possible on official firmware, maybe possible on dingoo linux
and palette/video mode function are missing too from entry.a
I think the future next way to go is using dingoo linux when it will be more useable

Yes I've discovered many things about the Dingoo :-/

Basically the LCD screen does not use the jz4740 LCD controller - it uses a separate controller.
This means that things like vsync, 8-bit color will not ever be available.

However, the TV out does use the jz4740 so for it we do have the option of different color modes and vsync, etc.

I wonder if Booboo will ever support this in Dingux?

What are the drawbacks of the missing vsync? Is this responsible for the screen tearing some people reported?

A Vsync signal is used to determine what part of the screen the LCD controller is currently drawing.
It's very useful for stopping screen tearing but is by no mean the only way of doing.
For example the GP32 has no vsync capability however it does have other register that tell you which line is currently being drawn. Using this, a programmer could create a very accurate timer in sync with the regular refresh period to simulate a vsync.
Perhaps the same thing can be done with the Dingoo.

Thanks slaanesh for the comprehensive explanation.

Hi,

Do you know which kind of controller it's using and why is there 2 controllers ?

So far i can't obtain any interrupts from the LCD.

I don't know if the format was already decoded but i just made a text file to describe to .app files in order to get ride of entry.a and create really small executable files.

http://pagesperso-orange.fr/franck.charlet/dingoo_app_format.txt