This program has some nice pixel effects. All colors are drawn using memblocks.

                                    ` This code was downloaded from The Game Creators
                                    ` It is reproduced here with full permission
                                    ` http://www.thegamecreators.com
                                    
                                    REM Project: Visualizer
REM Created: 10/18/2005 4:06:59 PM
REM
REM ***** Main Source File *****
REM



gosub initvar

gosub initscreen

gosub initcolors

gosub mainloop





initvar:


screenx as integer
screeny as integer
depth as integer
bpp as integer
blocksize as integer
memptr as dword
screenptr as dword
ycount as integer
xcount as integer
red as integer
green as integer
blue as integer
colorhold as dword
x as integer
y as integer
pixcol as dword
s as float
colorhold as dword

s=1

return






initscreen:

p=2

sync rate 0
sync on

hide mouse

screenx = 320
screeny = 200
depth = 32

bpp = depth/8

blocksize = screenx*screeny*bpp

make memblock 1,blocksize

set display mode screenx,screeny,depth

memptr = get memblock ptr(1)
screenptr = get pixels pointer()


dim color(screeny,screenx) as dword
dim oldcolor(screeny,screenx) as dword

return





initcolors:








for ycount=0 to screeny-1
   for xcount=0 to screenx-1
      color(ycount,xcount)=rgb(rnd(255),rnd(255),rnd(255))
   next xcount
next ycount

return



mainloop:

do




gosub background


gosub mouse

gosub draw




sync
loop

return



background:

invert=0

if spacekey()=1
   invert=1
endif

if shiftkey()=1
   gosub initcolors
endif

if upkey()=1
   s=s+.01
endif

if downkey()=1
   s=s-.01
endif

if returnkey()=1
   p=p+1


   if p>2
      p=1
   endif
endif


for ycount=0 to screeny-1
   for xcount=0 to screenx-1
       oldcolor(ycount,xcount)=color(ycount,xcount)
         color(ycount,xcount)=(color(ycount-1,xcount+1)+color(ycount+1,xcount-1)+color(ycount-1,xcount-1)+color(ycount+1,xcount+1))/4
         if invert=1
            color(ycount,xcount)= colorhold
            colorhold=oldcolor(ycount,xcount)/s
            endif
         Write memblock dword 1,ycount*screenx*bpp+xcount*bpp,color(ycount,xcount)

   next xcount
next ycount

return



mouse:
mx=mousex()
my=mousey()

for a=0 to 40
   for b=0 to 40
      color(my+a,mx+b)=rgb(255,255,255)
   next zcounta
next ycount
return


draw:





lock pixels

copy memory get pixels pointer(),memptr,blocksize

unlock pixels

set cursor 0,0
print screen fps()
print s

if p=2
print "Press space to scroll and shift to reset colors"
print "Adjust color effect using up and down then hold space"
print "Press enter to hide text"
endif


return