How do I program in 640x480x256

I know how to use move(source, dest, count),
but 640x480 can only have 320x200 of the screen.
How do I get the full screen memory. (640x480).
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StylerConnect With a Mentor Commented:

  If you want Raid you can grant this answer or not.

  INT 10h AX=4F02 - set video mode
          BX=mode (101h - 640x480x256)

          BH = subfunction
          00h select video memory window
          DX = window address in video memory
               (in granularity units)
          01h get video memory window
  Return: DX = window address in video memory (in gran. units)
          BL = window number
             00h window A
             01h window B

Just I want to have some Experts score
In VESA modes (>013h - 320x200) video memory consists of banks that can be switched. If you need to use all screen video memory then you have to draw one bank then increase bank and draw it and so on. Number of banks depends on Graphics mode. You can get excellent Grafx unit :  8-15-16 bit color; resolution up to 1600x1200, it also have bankswitching and all you need.  It can be downloaded at : ""
RaidAuthor Commented:
By your friend, Raid:
Sorry Jack_P50, it was a good answer, but unfortunatly,
it was not what I was looking for.  What I really meant by
that question, is to extend the screen memory so that
I can do the "MOVES" and assembly of my own, Thanks Anyway.
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RaidAuthor Commented:
Sorry to not include this, but I think your answer was right,
but I would like to know more about how to switch the banks so I can make a program in hi-res mode(640x480x256), using my own routines.

I have some .BGI files for using with Borland Pascal
And (I am not sure) I have source code for making BGI files.
If you are interested, send me a mail to
I will mail the files to you.


  Hello friend Raid!  Styler is alive!

  I have documentation on VESA Standart 1.2 (may be and 2.0)
  and I sent it you to your e-mail attaching archive with this

     I want you to do what you want with maximal perfomance!

  P.S. My e-mail is (if you want you
       can send me a letter).
When IBM designed their PC they left only 64KB window for video memory. But the high-res modes use more than 64KB. And the different video cards have their own opinion how to handle these high-res modes. In most cases that is implemented by bank-switching. The problem is that there are too many cards on the market and their command sets are different. I (like the others) suggest you to use the VESA interface for your routines.

RaidAuthor Commented:
Raid Here, Yes Styler, that document
was excellent.  I know just about
everything there needs to know about
Vesa Programming except one thing...
Bank Switching, that document said
something about "to see about bank
switching, look in the 'PC-GPE files'"?
Am I right.  If I am, can you send them.

  Let's we disport Raid!!!

  I'll send you these files (all what I have)
  on pc-gpe.
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