[cctalk] Re: undocumented instructions including HCF [was: System 360 question]

The NMOS 6502 has a number of undocumented lock-up opcodes. However, they arise as a consequence of its instruction decoder PLA and weren't intended for testing like the 6800 HCF. They were eliminated in the 65C02, though later versions add the STP opcode as an intentional way to halt the CPU until reset. -- ------------------------------------ personal: http://www.cameronkaiser.com/ -- Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser(a)floodgap.com -- Eggheads unite! You have nothing to lose but your yolks. -- Adlai Stevenson