michael@otago.ac.nz (05/30/91)
In article <772@goblin.ntg.com>, dplatt@ntg.com (Dave Platt) writes: > There is NO preferred method for tail-patching. It should not be done. .. > The result? If you install a tail-patch on a trap that Apple is using > as a secondary bug-fixer, then you will _disable_ Apple's bug fix! The > machine on which you're running will probably exhibit odd symptoms, due > to the fact that a necessary patch has been partially or completely > disabled. I have always wondered, though, whether or not it would be legitimate to look at the trap address before you tail patch it and only do so if it is > ROMBase - meaning that it doesn't have any bug-fix traps and therefore you (presumably) couldn't cause these sorts of problems. Of course such an approach would run the risk of abruptly ceasing to function under new system releases, etc, but I can't see why it wouldn't work... Michael(tm) Hamel, Computing Services Centre, University of Otago, New Zealand DUGGLEBY (n.) The person in front of you in the supermarket queue who has just unloaded a bulging trolley on to the conveyor belt and is now in the process of trying to work out which pocket they have left their cheque book in, and indeed which pair of trousers.
neeri@iis.ethz.ch (Matthias Ulrich Neeracher) (05/30/91)
In article <1991May30.090103.444@otago.ac.nz> michael@otago.ac.nz writes: >In article <772@goblin.ntg.com>, dplatt@ntg.com (Dave Platt) writes: > >> There is NO preferred method for tail-patching. It should not be done. >.. >I have always wondered, though, whether or not it would be legitimate to >look at the trap address before you tail patch it and only do so if it is >> ROMBase - meaning that it doesn't have any bug-fix traps and therefore you >(presumably) couldn't cause these sorts of problems. > >Of course such an approach would run the risk of abruptly ceasing to function >under new system releases, etc, but I can't see why it wouldn't work... The problem with this is that an MacPluses and MacII's, an *enormous* number of traps are patched nowadays, you'd probably have a real hard time to find unpatched ones. Is there anybody who might support these unscientific ramblings with some hard numbers ? How many traps are patched on a MacII for System 6.0.7 ? For System 7 ? Matthias ----- Matthias Neeracher neeri@iis.ethz.ch "These days, though, you have to be pretty technical before you can even aspire to crudeness." -- William Gibson, _Johnny Mnemonic_