https://en.wikipedia.org/wiki/Hewson_Consultants Usages: Exolon: https://www.worldofspectrum.org/infoseekid.cgi?id=0001686 Marauder: https://www.worldofspectrum.org/infoseekid.cgi?id=0003030 Cybernoid: https://www.worldofspectrum.org/infoseekid.cgi?id=0001196 Gunrunner: https://www.worldofspectrum.org/infoseekid.cgi?id=0002181 Protections: 1. XOR FC00 LD BC,029D FC03 LD HL,FC13 FC06 LD DE,FC14 FC09 LOOP LD A,(DE) FC0A XOR (HL) FC0B LD (HL),A FC0C INC HL FC0D INC DE FC0E DEC BC FC0F LD A,B FC10 OR C FC11 JR NZ,LOOP 2. Non-standard file headers FE90 LD A,(FC21) FE93 CP 2A FE95 JR NZ,LD_HEADER