Dave Walker wrote:
> Rich, > > I once looked into this. The copy protection itself is easy enough to > break - if I remember correctly it was based on reading some hidden > sectors from the microdrive. The issue was that it had to be read into > a specific address in memory and executed from there - and the address > in question only seemed to work on an unexpanded QL. This sounds very much like the protection on Paraoh (right name?) - where you had to navigate through a purple(ish) maze with egyptian style music in the background, avoiding naties like snakes. A bit of code was loaded from a hidden file (the directory had to be changed before it could be loaded, and changed again afterwards to rehide it) into the base of the screen memory ($20000) where upon it was called. Psion Chess _WAS_ position dependent and the boot program RESPR'd lots of memory to get the right address - if my memory serce me right it used the same protection method (seactor header) as The Pawn... > I might have to > dig out my copy and see (assuming it still works) whether anything > better can be done. It loads as a RESPR (a=RESPR(001024):LBYTES mdv1__,a:call a) and it uses the cartridge random ID number from the header of each sector (got via vector 12A). If the ID on the key cartridge matches the required number, it then continues with the boot program (OPEN_IN#3,"mdv1_ ":FLRUN) - if the ID didn't match it reset the machine. The code loaded (mdv1__) contains the code for FBOOT, FSAVE and FLRUN. It's very easy to break...a little modification to the check (2 m/c instructions) will suffice - I can dig out the details of a change, if you want. > Dave > > ----- Original Message ----- > > From: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > > To: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > > Sent: Wednesday, June 19, 2002 7:55 PM > > Subject: [ql-users] QL Pawn > > Does anyone have a copy of the original program by Magnetic Scrolls > complete with manual etc. they would like to sell?? I have had a > good offer... > > This is not much use to modern QLers after all , as no-one seemed to > be able to crack the copy protection (shame). > > Rich Mellor > RWAP Software > 7 Common Road, Kinsley, Pontefract, West Yorkshire, WF9 5JR > TEL: 01977 614299 > http://hometown.aol.co.uk/rwapsoftware
