How to use images? revised..

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Dex4u

Joined: 08 Feb 2005
Posts: 1601
Location: web

Dex4u 17 Jun 2006, 13:00

I am also a great believer in KISS, here is some code, i made to display a 640x480 256 bmp for "Redragon", may help others.
Note: Change "test.bmp" before assembling, to change image.
Run the exe to put it on a floppy, fasm code included.
http://www.dex4u.com/Redragon/BmpView.zip
EDIT: Please just ask and i will upload it again (as need space).
Hope this helps.
Works in qemu too.

Last edited by Dex4u on 19 Jun 2006, 15:11; edited 2 times in total

17 Jun 2006, 13:00

ATV

Joined: 31 Aug 2004
Posts: 109
Location: Finland

ATV 19 Jun 2006, 14:21

Adam, here is my old pascal/asm routine to put pixel into screen mode $12. You need also handle high/low nibble.
To copy bmp line, mode $13 need only "rep movsb", but mode $12 lots of more code. Current BootBmp with 256 colors has 16 bytes free, maybe it is possible if you remove all messages and all extra stuff.

Code:

SCREENBYTES := 80;   { 80 for 640*480 or 100 for 800*600 }
Procedure SetPixel(x, y: Word; Col: Byte); Assembler;
Asm
  push ds
  mov  ax,Seg @Data
  mov  ds,ax
  mov  ax,$A000
  mov  es,ax
  mov  ax,[SCREENBYTES]
  mul  [y]
  mov  di,[x]
  mov  cx,di
  shr  di,3
  add  di,ax
  mov  dx,$03CE
  mov  ax,$0205     { Set writemode 2 }
  out  dx,ax
  and  cl,$07
  mov  ax,$8008     { Set bit mask cl }
  shr  ah,cl
  out  dx,ax
  mov  al,es:[di]   { Some graph card need dummy read before write }
  mov  al,[Col]
  mov  es:[di],al
  mov  ax,$FF08     { Set bit mask FF }
  out  dx,ax
  mov  dx,$03CE     { Set writemode 0 }
  mov  ax,$0005
  out  dx,ax
  pop  ds
End;

19 Jun 2006, 14:21

Adam Kachwalla

Joined: 01 Apr 2006
Posts: 150

Adam Kachwalla 19 Jun 2006, 20:56

What are the values of [di] and [Col]?

19 Jun 2006, 20:56

Adam Kachwalla

Joined: 01 Apr 2006
Posts: 150

Adam Kachwalla 19 Jun 2006, 21:22

Dex4u: It appears that your BMP viewer doesn't work too well.

19 Jun 2006, 21:22

Dex4u

Joined: 08 Feb 2005
Posts: 1601
Location: web

Dex4u 19 Jun 2006, 21:47

Adam Kachwalla wrote:

Dex4u: It appears that your BMP viewer doesn't work too well.

It may help if you say in what way Wink

19 Jun 2006, 21:47

ATV

Joined: 31 Aug 2004
Posts: 109
Location: Finland

ATV 20 Jun 2006, 13:00

That is about 10 years old pascal source, that time I didnt use many comment in my source.
col=color=0..15
x=0..639
y=0..479
di=(x shr 3)+80*y
cl=x and 7
Note: it is using writemode 2
You can also use writemode 0 but then you have to set right color plane your self. For more information search WriteEgaPlane in net.

20 Jun 2006, 13:00

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