Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!cs.utexas.edu!uunet!mcvax!unido!tub!tubopal!alderaan From: alderaan@tubopal.UUCP (Thomas Cervera) Newsgroups: comp.sys.atari.st Subject: Re: Multitasking on the ST Message-ID: <675@opal.tubopal.UUCP> Date: 11 Aug 89 11:54:37 GMT References: <8908021826.AA05333@ucbvax.Berkeley.EDU> <15627@watdragon.waterloo.edu> <652@opal.tubopal.UUCP> <471@tw-rnd.SanDiego.NCR.COM> <1066@philmds.UUCP> Reply-To: alderaan@tubopal.UUCP (Thomas Cervera) Organization: Technical University of Berlin, Germany Lines: 26 In article <1066@philmds.UUCP> leo@philmds.UUCP (Leo de Wit) writes: >In article <471@tw-rnd.SanDiego.NCR.COM> johnl@tw-rnd.SanDiego.NCR.COM (John Lindwall) writes: >[...] In the current situation it is just as well feasible for >instance by an application program to thrash the space of the shell it >was invoked by. So if you insist on security, you should insist on it >right now already. Absolutely correct. But using a multi-tasking system this problem will multiply. >An MMU alone probably won't hack it; you will probably want a 680x0 >(x >= 1) to be able to page in new memory (a 68000 doesn't maintain >enough internal information to be able to restore correctly from a >BUSERR). But isn't there any software solution to that ? (I'm looking on primitive MMU versions on PDPs where the operating system does a part of context- saving work on failed EMT or TRAP recovery). The LSI11 processors are very much like the M68k family. Or is this really impossible on 680x0 ? (Remember, I'm only a dumb physicist :-) ) -- Thomas Cervera | UUCP: alderaan@tubopal.UUCP SysMan RKOpdp (RSTS/E) | ...!unido!tub!opal!alderaan (Europe) D-1000 Berlin 30 | ...!pyramid!tub!opal!alderaan (World) Motzstrasze 14 | BITNET: alderaan%tubopal@DB0TUI11.BITNET (saves $$$)