Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!decvax!mcnc!ecsvax!bet From: bet@ecsvax.UUCP Newsgroups: micro.pc,net.micro.pc Subject: bug in DOS 2.00 -- divide by zero causes crash Message-ID: <2025@ecsvax.UUCP> Date: Fri, 17-Feb-84 19:45:51 EST Article-I.D.: ecsvax.2025 Posted: Fri Feb 17 19:45:51 1984 Date-Received: Sat, 18-Feb-84 10:14:05 EST Lines: 19 I seem to have discovered a bug in DOS 2.00. Zero-divide interrupts aren't correctly trapped, so dividing by zero causes a crash. DOS 1.00 and 1.10 caught the interrupt, reported "Divide Overflow", and returned to DOS. Make the following a .com file: (it's easy with the 2.00 debugger) xor dx,dx mov ax,10 xor cx,cx div cx int 20 Now run it under DOS 1.00 or 1.10. Divide Overflow. DOS 2.00: space shot. If anyone has an interrupt handler written (preferably as an end-and-remain- resident .com file) please let me know. I am trying to write one, but keep getting "memory allocation error, cannot load COMMAND.COM. System halted". when I try it out with the above test file. {decvax,akgua}!mcnc!ecsvax!bet Bennett Todd