Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!mcnc!ecsvax!ranger From: ranger@ecsvax.UUCP (Rick N. Fincher) Newsgroups: comp.sys.apple Subject: Re: 65C816 programming weirdness; is it true? Message-ID: <2515@ecsvax.UUCP> Date: Mon, 5-Jan-87 11:00:57 EST Article-I.D.: ecsvax.2515 Posted: Mon Jan 5 11:00:57 1987 Date-Received: Mon, 5-Jan-87 21:48:35 EST References: <2504@ecsvax.UUCP> <1162@cbmvax.cbmvax.cbm.UUCP> Organization: UNC Educational Computing Service Lines: 33 Summary: I agree... In article <1162@cbmvax.cbmvax.cbm.UUCP>, daveh@cbmvax.cbm.UUCP (Dave Haynie) writes: > > Keywords: IIGS, 65C816, assembly language, 8/16 bit modes > > Summary: I think 65816 is easier... Dave, I agree with your comments, I misunderstood the gist of the 1st question. I think that folks who have programmed primarily on the 68000 and 80xx series will have some problems dealing with differences in the way the '816 does things. I have seen some assemblers that use the convention of changing from 8 to 16 bit registers with a macro call that the assembler implicitly changes the mode if necessary, basically they define their own byte and word mnemonics. This is not the way the ORCA assembler works, however, and it is the Western Design Center standard as well as Apple's. To me keeping track of what register width I'm using is a lot simpler than keeping track of, say, segments in the 8086 architecture, although the '816 is segmented, I find it much more straightforward. My mindset is that of someone who programs in assembler mostly on 65xx processors and only does 80xx when he has too. The 68000 is a Cadillac, but I think that beginning assembly language pro- grammers have trouble remembering all the mnemonics for byte word and long. It is undoubtedly a better way to go once you have committed all of the mnemonics to memory, however, since it avoids the ambiguity of the register width that you have with the '816. To me learning to program the '816 was a natural progression from the 6502, everything made sense, the only thing I considered 'weird' was the stack relative stuff because it was new on the 816, although this has been on other processors before. I see you point about 'weirdness' however, the register width mode switching is weird in that it is done in a completely different way from most processors. Thanks for the comments. Rick Fincher ranger@ecsvax >