[fpc-pascal] Cross Platform Save/Restore Screen

[Michael Van Canneyt]

On Tue, 20 Jun 2006, Michael Preslar wrote:

> Back in the DOS Turbo Pascal days I could do the following
>
> type
> screentype= array[1..4000] of byte;
> screenptr=^screentype;
> var
> screen1: screenptr;
>
> procedure savescreen(scr:byte);
> var
> sc1: byte absolute $b000:0;
> sc2: byte absolute $b800:0;
> begin;
> if screenaddress=$b000 then move(sc1,screens1^,4000);
> if screenaddress=$b800 then move(sc2,screens1^,4000);
> end;
>
> procedure restorescreen(scr:byte);
> var
> sc1: byte absolute $b800:0;
> sc2: byte absolute $b000:0;
> begin;
> if screenaddress=$b000 then move(screens1^, sc2,4000);
> if screenaddress=$b800 then move(screens1^, sc1,4000);
> end;
>
> Now I'm stuck. How can I do the same for Win32 Console apps, and
> *nix/*bsd console apps?

The short answer: You simply can't...

You must use the 'video' unit to do this kind of tricks in a more or less
cross-platform way, but you'll have to rewrite your code completely.

You may also want to have a look at the ncurses unit and the various
descendents, ocrt, ncrt.

video is documented, and is part of the RTL.
The others are in the packages.

Michael.