Code:
@echo off
setlocal
set bb=%@balloc[256]
for /l %i in ( 0, 1, 255 ) set rv=%@bpoke[%bb,%i,1,%i]
set filename=testfile.dat
set handle=%@fileopen[%filename,w,b]
set rv=%@bwrite[%bb,0,%handle,0,256]
set rv=%@fileclose[%handle]
set rv=%@bfree[%bb]
type /x %filename
del /q %filename
endlocal