6 replies to this topic

[Justin Payne]

Does anyone have a simple code in assembly that loads an image into video memory?

Thanks,

[JAC!]

Hi,
As opposed to BASIC, you would not load it to the video memory. Instead you normally setup a display list and include the picture data as binary into the executable directly. See attached ZIP file.

;
;	>>> Simple picture display in assembler <<<
;
;	2011-09-16 by JAC! 


	org $2000

start	mwa #dl $230		;Set DL points
	mva #$34 708		;Set 3 colors
	mva #$38 709
	mva #$0e 710
	jmp *

dl	.local
dc	= $0e			;Antic mode E/graphics 15
	
	.byte $70,$70,$70	;3*8=24 blank lines in PAL

	.byte $40+dc		;LMS instruction for upper half
	.word picture
:95	.byte dc		;1+95=96 lines, 40 bytes each

	.byte $40+dc		;LMS instruction for upper half
	.word picture+$f00	;Will be at 4k boundary
:95	.byte dc		;1+95=96 lines, 40 bytes each

	.byte $41		;Restart with vertical blank
	.word dl

	.endl

	;Picture has $1e00 bytes, $f00 for the upper half, $f00 for the lower half
	;In order to prevent ANTIC from cross a 4k boundary, we chose the base address
	;in a way that the upper half is in the first 4k, and the lower half in 2nd 4k.
 
	org $2100
picture	ins "SpaceHarrier.pic"

Attached Files

•  DisplayPicture.zip   10.03K   49 downloads

Edited by JAC!, Fri Sep 16, 2011 4:40 AM.

[MaPa]

DELETED

Edited by MaPa, Fri Sep 16, 2011 4:37 AM.

[Justin Payne]

WOW!! It was THAT simple?!? Thank you very much!!!

[JAC!]

It's assembly, it is "simple" by definition, and sometimes this makes it hard . Real coder's .. you know..

[Justin Payne]

Well, even simple it helped. I found so many things about display lists, which I completely got, and lots of stuff with P/M graphics, but nothing about just loading an image into video memory.

[JAC!]

So you mean from disk file? Like you'd do it in TurboBasic?

GRAPHICS 15
OPEN #1,4,0,"D:PICTURE.PIC"
BGET #1,DPEEK(88),7680
CLOSE #1

In which assembler syntax do you need the reply?

Edited by JAC!, Fri Sep 23, 2011 11:30 PM.