Adventures in PC Emulation

This is part 5 of a series of articles investigating various floppy copy-protection schemes seen on the IBM PC platform. You may wish to read the previous entries in this series: Part 1, covering Formaster Copy-Lock Part 2, covering Softguard Superlok Part 3, covering Electronic Arts Interlock Part 4, covering Vault Prolok XEMAG was a commercial disk duplicator that provided services to companies such as Electronic Arts, Activision, IBM, Ashton-Tate, and Oracle. XEMAG traces its origins to the disk duplication department of Peripheral Marketing, Inc., from which it was spun-off in 1983. By 1983 they were duplicating a million floppies a month.  Reproduction of a design appearing on some XEMAG swag   For some background into what working at XEMAG was like, you may wish to read  this interview with Peter Brown, a former XEMAG employee. XEMAG was acquired by the Xidex Magnetics Corporation  in February of 1983, for $3.78 million . Xidex would then acquire disk manufacturer Dysan  in ear