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What is fastest way to access video memory in BP?...

What is the fastest method to access the video memory in Borland
Pascal for mode mov ax,0013h, int 10h (320*200*256 colors)?..

I've now developed a unit what directly writes into the video memory
via an assembler routine on memory offset A000:0000 etc.. I thought
that this was the fastest way to do it, but are there other options?
I've seen demos and games who have a much faster VGA routine
than my programs, and I need a faster routine because I want that my
code also runs on slower machines (386, or even 286/8086/88).

Thanks in advance,
  -=Judiliochromis=-

 

Re:What is fastest way to access video memory in BP?...


Quote
judi...@xs4all.nl (JuDIli0Chr0mIs) wrote:
>I've now developed a unit what directly writes into the video memory
>via an assembler routine on memory offset A000:0000 etc.. I thought

You would be better suited to use sega000 for future compatibility
with DPMI mode compiling.

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Re:What is fastest way to access video memory in BP?...


Quote
>What is the fastest method to access the video memory in Borland
>Pascal for mode mov ax,0013h, int 10h (320*200*256 colors)?..

The assembly mov is the fastest. You should try to use a 2 byte mov or
a rep movs if possible. Usually the actual mov does not take the time
but the instructions to setup for the mov. Try to optimize these.
Also note that in almost all cases accessing video memory is much
slower than normal memory. I've seen some programs that actually
create a copy of the screen in RAM then move the whole screen
memory to the video memory.

Re:What is fastest way to access video memory in BP?...


-=[ joeja...@webworldinc.com (Joe Jared) wr0Te: ]=-

Quote
>>I've now developed a unit what directly writes into the video memory
>>via an assembler routine on memory offset A000:0000 etc.. I thought
>You would be better suited to use sega000 for future compatibility
>with DPMI mode compiling.

Hmm.. Sounds difficult.. I'll search for some DPMI documentation if
available.. thanks..

Re:What is fastest way to access video memory in BP?...


-=[ "Bean" <th...@igateway.com> wr0Te: ]=-

Quote
>>What is the fastest method to access the video memory in Borland
>>Pascal for mode mov ax,0013h, int 10h (320*200*256 colors)?..
>The assembly mov is the fastest. You should try to use a 2 byte mov or
>a rep movs if possible. Usually the actual mov does not take the time
>but the instructions to setup for the mov. Try to optimize these.
>Also note that in almost all cases accessing video memory is much
>slower than normal memory. I've seen some programs that actually
>create a copy of the screen in RAM then move the whole screen
>memory to the video memory.

Hmm.. i'll try some of these tips, thanks!...

   -     -     -   -  - - -----------------------
 Sincerely, _-^JuDIli0Chr0mis^-_
 Raymond Dresens / judilio@xs4all -- my UIN/ICQ number: #3818673
 Visit the lair.... http://www.xs4all.nl/~judilio
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