Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/5/84; site cvl.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!umcp-cs!cvl!liang From: liang@cvl.UUCP (Eli Liang) Newsgroups: net.micro.apple Subject: Re: Re: Undocumented 6502 Opcodes Message-ID: <139@cvl.UUCP> Date: Wed, 6-Mar-85 18:40:22 EST Article-I.D.: cvl.139 Posted: Wed Mar 6 18:40:22 1985 Date-Received: Sat, 9-Mar-85 19:58:55 EST References: <9@zurton.UUCP> <381@utai.UUCP> Organization: Computer Vision Lab, U. of Maryland, College Park Lines: 23 > I tried to execute some of the unused 6502 opcodes and found one that > seems to conform to the described HCF specs. That is, the processor > seems to hang up and doesn't go anywhere until it gets a reset. > Of course, I didn't let it sit there long enough to find out > if the processor would self-destruct. If anybody is willing to > satisfy our curiosities, the op-code was $12. As noted, the presence > of the HCF instruction may depend on the chip manufacturer. Unfortunately, > I forgot to check who made mine. > Greg Dudek This is the exact instruction which I mentioned in my previous article. $12. I think that there must be some truth in the HCF instruction for the 6502. -eli -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Eli Liang --- University of Maryland Computer Vision Lab, (301) 454-4526 ARPA: liang@cvl, liang@lemuria, eli@mit-mc, eli@mit-prep CSNET: liang@cvl UUCP: {seismo,allegra,brl-bmd}!umcp-cs!cvl!liang