I'm sure that BXH was inspired by TXI and TXH.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Assembler List <ASSEMBLER-LIST@LISTSERV.UGA.EDU> on behalf of Charles Mills <charl...@mcn.org> Sent: Tuesday, February 12, 2019 12:52 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Using both ends of a register Architects did a pretty darned good job of designing an instruction set in 1962 that has more or less hung together in 2019. (I know you were kidding, but what I say is still worth saying.) BXH, the direct ancestor of JXH, is an original S/360 instruction IIRC. Before anyone dreamed of high meaning part of a register. All of the BH and similar extended mnemonics have the same issue. AHHHR does sound like something a pirate would say. Charles -----Original Message----- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of Steve Smith Sent: Tuesday, February 12, 2019 9:38 AM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Using both ends of a register Well, there are, and they all have mnemonics that could easily be confused with halfword instructions... e.g. LFH, AHHHR, AIH. JCT is not even close to one of them. It sounds like Martin's message was cut-off mid-stream, and I presume he meant to say JCTH (Branch Relative on Count High); which is not to be confused with JXH (Branch Relative on Index High), where "High" means something else. Makes me think some architects were High. :-)
