Apricot in the US

On 15 Jun 2010 at 16:29, Chris M wrote: Just curious, how would you do this, since the schemes could be quite varied? Another variation was to encrypt the code as it was stored on the floppy and decrypt in memory before execution, based on the results of the copy-protection check. Many games were boot-up games, meaning that they didn't use DOS; they simply booted up into a game. An example of this creativity is demonstrated by early versions of Harvard Graphics, which stored the letters "HGC" in the inter-sector gap on one track and used the "Read Track" NEC 765 command to check for it. That was pretty clever, as it not only used an unconventional way of getting to the gap bytes, but also depended on the disk being produced on a whole-track-write system to preserve the synchronization over the sector write splice. I seem to recall that when IBM first demonstrated the PS/2, no 3.5" copies of Lotus 1-2-3 were available, so the marketing people resorted to one of the copy-protection defeating packages to run their demo. --Chuck