How to write massive amounts of hard data to a file?

To write sig:

;Open Test Executable
fileout = OpenFile("test.exe")

SeekFile fileout,FileSize("test.exe")


;Write Signature for locating start of data
WriteByte fileout,Asc("R")
WriteByte fileout,Asc("O")
WriteByte fileout,Asc("B")

CloseFile fileout

End

To locate sig:

file = OpenFile("test.exe")

While Not Eof(file)
	If ReadByte(file)=Asc("R") 
		;Found first
		If ReadByte(file)=Asc("O")
			;Found second
			If ReadByte(file)=Asc("B")
				;Found third
				found=FilePos(file)
			EndIf
		EndIf	
	EndIf
Wend

While Not KeyHit(1)
	Text 20,20,Found
Wend

End

I've got more complete code if you want.