Using FOR/NEXT I still ran into limitations as well. However, a programmer friend suggested the following simple change - remove the line feed for each write - and I easily wrote 100,000 characters to a line. Downloaded UltraEdit and it saw as 1 line, 100,000 characters. Logic for my script is to not use CRLF with any write. Duh!
Bill

code:
$Fil = "C:\Temp\wl.txt"
$Char=A
OPEN (1, $Fil, 5)
FOR $Idx=1 to 100000
  $wri = writeline (1, "$Char")
NEXT
CLOSE (1)