Mathy, on Fri Jan 1, 2010 8:05 AM, said:
Should work on my 1MB+ XEGS too. Great demo! (Only used Atari800Mac to check it out)
Happy MMX to you too.
I'd be interested in knowing what it does on various machines.. It definitely will not work correctly on any machine that does not have true separate antic and cpu access to extended ram (bits 4 & 5 of PORTB have to be like a stock 130xe).
The "effects" on all the slides are the same.. Its 320x200x8 colors via per-scanline switching of color reg. 2 between red, green, and blue. And per-scanline bitmap data switching between extended banks 0,1, and 2..
Kewl thing about this system is that ALL of your base ram is free for your own programming.. All of the bitmap data and display list data is stored in extended ram banks 0-3.. The only thing that resides in base ram is a DLI routine which occupies the first 63bytes of page 6. And of course, in the case of this demo, the BASIC program that loads everything..
Heres how to make the .8C8 picture files I used..
Load up photoshop and open a 320x200 picture using standard 24bit RGB color setting..
Draw your picture using the folllowing colors:
Or set up an indexed color pallete of these exact colors, and have photoshop convert an existing image to them..
One you have a 320 x 200 image in these colors, save it back as an normal RGB color .BMP or .PSD image.
1) reload the image and make sure it's in normal RGB color mode..
2) Now go to the "channels" pane and dupilcate the RED channel. Delete the original RED, GREEN, and BLUE channels..
3) copy whats left in the picture into the copy buffer..
4) Open a new 320x200 image, this time select "bitmap" instead of RGB color.. and paste the copy buffer into this image..
5) Save this image as RED.BMP (select WINDOWS, 1-bit BMP, and check the "flip row order" box).
Repeat steps 1-5 for the Green and Blue components of the image..
You should end up with three separate 1-bit .BMP image files..
Load all three of them into a good Hex editor..
On each file, delete the first 62 bytes (the .bmp header).. Delete the last 2 bytes (padding bytes that photoshop seems to add.)
Your file size should be exactly 8000 bytes per file now..
Invert the bits on all three files..
Now paste the Green file onto the end of the red file.. and then paste the blue file onto the end of that..
You should now have a 24000 byte file.. Save it as PICTURE.8C8, and copy it into the demo .ATR disk image..
Modify the BASIC program (lines 2000-2090 handle the file loading) by replacing the filename on one of the lines with "D:PICTURE.8C8".
Run the program and see how it looks...
I know this is a big pain in the ass... Maybe I'll make a quick routine that just loads standard 4bit .BMP files, and discards the 4th bit... Then you could just use Windows PAINT and save normal "16 color BMP files" (using only the 8 "primary" colors, of course)..