``````{ I made a small ASM-routine for accessing 4 GB data in 4 instructions: }

PROGRAM test32; {Works for TPW1.5}
{\$R-}
{Wim Smit 4-9-1994
Thanx to Jimmy Athens!}
USES WinTypes,WinProcs,WinCrt;
TYPE
word_array = ARRAY[0..0] OF WORD;
Pword_array = ^word_array;

VAR P:PWORD_Array;
H:THandle;
sub1,sub2,
segt: WORD;
i,
ofst: LONGINT;
BEGIN
WRITELN('BEGIN');

h := GlobalAlloc(GMEM_MOVEABLE OR GMEM_SHARE,2*70000);
IF (h = 0) THEN
Halt;
P := GlobalLock(h);
IF (P = NIL) THEN
Halt;

segt := SEG(p^);
FOR i := 0 TO 69999 DO           {fill the words with their index}
BEGIN
ASM
mov es,segt
db 66h                   {66h for 386 opcode}
mov bx, WORD(i)          {WORD() to fool Pascal}
db 66h
shl bx,1                 {ebx times 2: WORDs}
db 66h
mov ax, WORD(i)
db 26h
db 67h
db 89h
db 03h                   {these produce: mov  es:[ebx],ax}
END;{asm}
END;{i}
{Now test it by reading the words:}
FOR i := 32762 to 32770 DO       {read over a segment-boundary}
BEGIN
ASM
mov es,segt
db 66h
mov bx, WORD(i)          {= mov ebx, i}
db 66h
shl bx,1                 {times 2: we're indexing WORDs}
db 26h
db 67h
db 8bh
db 03h                   {= mov ax, es:[ebx]}
mov sub2, ax
END;{asm}
sub1 := p^[i];
WRITELN(i:3,':',sub2,' ',sub1);
END;{i}

GlobalUnlock(h);
GlobalFree(h);
WRITELN('DONE');
END.

{
Run the program and see the difference:
BEGIN
32762:32762 32762
32763:32763 32763
32764:32764 32764
32765:32765 32765
32766:32766 32766
32767:32767 32767
32768:32768 0      <-Here 16 bit index will wraparound to p^[0]!
32769:32769 1
32770:32770 2
DONE

Thus, by choosing the right db's, one can access huge arrays of bytes,
words and longints etc.
Isn't that great?
OK, it needs a 386 or better, but don't we all have that?
}
``````