I always get the following error while tring to run oh51 tool. C:\Keil\C51\BIN>oh51 main.obj OBJECT TO HEX FILE CONVERTER OH51 V2.6 COPYRIGHT KEIL ELEKTRONIK GmbH 1991 - 2001 GENERATING INTEL HEX FILE: main.hex *** ERROR: UNKNOWN RECORD TYPE 0FH *** OH51 ABORTED.