On 12 Feb 2007, at 12:13, Dilwyn Jones wrote: > QL jobs have a JMP.L job_start_address instruction in the first few > bytes, to jump past the $4AFB flag and job name. This could in theory > (never tried this part) be hacked to jump to an extra bit of code > tacked onto the end of a program to run a 'virus', which ends with the > original JMP.L job_start_address to run the program from its original > execution address. > > I *HOPE* I am wrong and this cannot be done. But I'm also optimistic > that nobody on the QL scene would even dream of trying to write a > working virus!
Adrian Dickens in his QL Advanced User Guide shows how to set up a self-cloning program. (See 4.4.2) His program drew a set of coloured blobs across the screen. This went on until one of the blob sets hit the edge of the screen at which time all the programs committed suicide. This is not strictly a virus since you yourself have to start it going in the first place, but it gives an indication of what can be done. George _______________________________________________ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
