fpc/docs/go32ex/buffer.pp
1998-09-07 20:53:46 +00:00

52 lines
1.4 KiB
ObjectPascal

Program buffer;
uses go32;
procedure dosalloc(var selector : word; var segment : word; size : longint);
var res : longint;
begin
res := global_dos_alloc(size);
selector := word(res);
segment := word(res shr 16);
end;
procedure dosfree(selector : word);
begin
global_dos_free(selector);
end;
type VBEInfoBuf = record
Signature : array[0..3] of char;
Version : Word;
reserved : array[0..505] of byte;
end;
var selector,
segment : Word;
r : trealregs;
infobuf : VBEInfoBuf;
begin
fillchar(r, sizeof(r), 0);
fillchar(infobuf, sizeof(VBEInfoBuf), 0);
dosalloc(selector, segment, sizeof(VBEInfoBuf));
if (int31error<>0) then begin
Writeln('Error while allocating real mode memory, halting');
halt;
end;
infobuf.Signature := 'VBE2';
dosmemput(segment, 0, infobuf, sizeof(infobuf));
r.ax := $4f00; r.es := segment;
realintr($10, r);
dosmemget(segment, 0, infobuf, sizeof(infobuf));
dosfree(selector);
if (r.ax <> $4f) then begin
Writeln('VBE BIOS extension not available, function call failed');
halt;
end;
if (infobuf.signature[0] = 'V') and (infobuf.signature[1] = 'E') and
(infobuf.signature[2] = 'S') and (infobuf.signature[3] = 'A') then begin
Writeln('VBE version ', hi(infobuf.version), '.', lo(infobuf.version), ' detected');
end;
end.