Hi, somebody did excellent job creating an example of source code for OSD that we can understand (in C language):
http://www.micro-examples.com/public...d-superimposer
see also
http://www.micro-examples.com/public...089-pic-pal-tv

Whoa, nice find.

The 12F683 is one my favorite pics
I used it for my time fountain because it was just so cute and small and can even change clock speed on the fly.

My Time Fountain 00 (1 min 38 sec)

Too bad this is for PAL

I continue to be amazed by time mountains

The OSD however looks to me slightly useless. Perhaps you could mod the code to have the engine run on something with a higher clock speed so you dont end up with all of 3 lines of text, 8 columns of data or so available.

HI

very interesting project, could you explain a bit more in detail how the code works? (I know C programming)

As i understood you count the lines from the sync pulses, but how do you know when on the line to draw the line high for white or low for black?

shouldent the max voltage in PAL be 1V?

How many "pixels" are there in one line?

You have a 2D array (bitmap)for keeping track of where to put a pixel and functions for updating the array. The array is written to the screen at every new frame...right?

how does the WRITECHAR() function work?

thanks for sharing this great project!

nice find! seems very cool althought I know not much about C programming.. You could get somewhere!


damian

somebody did excellent job

I.e. not him, so I doubt he will know the details without having to figure it out just like you

Originally Posted by Mark Harris

The OSD however looks to me slightly useless.

I never said it is good for anything more than learning.
However for understanding the OSD internals, it's better than anything in assembler.