Path: utzoo!utgpu!water!watmath!clyde!bellcore!rutgers!tut.cis.ohio-state.edu!mandrill!neoucom!wtm From: wtm@neoucom.UUCP (Bill Mayhew) Newsgroups: comp.sys.ibm.pc Subject: Re: ???=>reBoot from a batch file????? Summary: The BIOS warm boot magic-cookie trick Message-ID: <1249@neoucom.UUCP> Date: 2 Jun 88 15:22:45 GMT References: <5537@megaron.arizona.edu> <32505@amdahl.uts.amdahl.com>,Organization: Northeastern Ohio Universities College of Medicine Lines: 38 If you jump into the the BIOS with location 0040:0072H set to the magic quatity of 1234H, and jump to the entry point of the BIOS, the system will perform a warm boot (i.e., no power-on self-test, etc.). Putting anything else in that memory location will force a cold boot. You can use DEBUG to enter the following sequence and save the result as WARMBOOT.COM: The blank line in the script below is necessary to get out of assemble mode! ---------------------- cut here ------------------------- a 0 mov ax,0040 mov ds,ax mov ax,1234 mov [0072],ax jmp f000:fff0 r cx 16 n warmboot.com w q ---------------------- end of script --------------------- Clip the above section out and save it in a text file. Then, redirect the text file into DEBUG thusly: debug < file.txt. This will automatically feed the commands in and create warmboot.com. Of course, you can always type the same sequence manually from your keyboard. INT 19H is brain damaged on most clone computers. I've yet to find a machine that the above method won't work on. --Bill wtm@neouocm.UUCP