From: mert0407 AT sable DOT ox DOT ac DOT uk (George Foot) Newsgroups: comp.os.msdos.djgpp Subject: Re: Strange Allegro related crash Date: 20 May 1997 19:35:01 GMT Organization: Oxford University, England Lines: 37 Message-ID: <5lsud5$2s3@news.ox.ac.uk> References: <5lrd29$p5b AT freenet-news DOT carleton DOT ca> NNTP-Posting-Host: sable.ox.ac.uk To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Precedence: bulk Paul Derbyshire (ao950 AT FreeNet DOT Carleton DOT CA) wrote: : My project implements a double-buffer, using two pages of a three page : Mode X screen for page flipping and the third stores a background image : (so the parallaxing can be done mostly with fast latch-register blits). (bug description snipped) I haven't a clue what the problem is, but try the following: 1) If you can remember what change you made before recompiling, go over it with a fine-tooth comb. In particular, look into how it would affect the screen updates. 2) Comment out unimportant sections of your code until you are left with just the screen display routines (you may need to replace the commented-out sections with `dummy' code to simulate sensible results), and see if the bug remains. If so, you have dramatically reduced the volume of code you need to check for bugs. 3) If not, put things back in one by one, or in groups where necessary, until it resurfaces. Then you know almost exactly which section of your code is causing the bug. 4) If the `culprit' section doesn't seem to be at fault itself, maybe it is a bug in Allegro, or a slight error in the way you are using it; repost then with more specific details Doing the above should help you break the problem down, anyway, and maybe you can provide a small working program which demonstrates the bug, which you could then send to Shawn (if he has time to look through it). -- George Foot Merton College, Oxford What's the wizard's password for? (dunnet)