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Re: Trick to knowing hex address alignment?

From Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups comp.lang.c
Subject Re: Trick to knowing hex address alignment?
Date 2020-10-13 14:13 -0700
Organization None to speak of
Message-ID <87r1q14yo0.fsf@nosuchdomain.example.com> (permalink)
References (6 earlier) <tQZgH.285811$r25.197877@fx08.iad> <rm1pnn$19i8$1@gioia.aioe.org> <nH7hH.227195$d95.116820@fx06.iad> <5FjhH.127886$MQ.102013@fx14.iad> <EEkhH.158197$NB.50157@fx20.iad>

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Richard Damon <Richard@Damon-Family.org> writes:
[...]
> As Joe mentioned, it could be a segment register, and some processors in
> the past had distinct 'Data' and 'Address' registers to allow saving a
> bit in many opcodes/addressing codes for specifying the register (or
> letting you have twice as many registers as otherwise). Such a machine
> might pre-validate an address loaded into an address register, but that
> might not actually delay the main execution (or it wouldn't be worth
> doing). On such a machine, you wouldn't load the pointer into one of
> these address register (unless you had a very dumb compiler) as the
> address registers would support the AND operation.
>
> Yes, I don't know of any processor that could be confused as 'modern'
> (at least for desktop/server level applications, might still be some
> embedded processors) with such registers, but they did exist, and maybe
> some of them had protected memory.
>
> Maybe the best know would have been the 80X86 with SI, DI, BP, and SP as
> 'address' registers and AX, BX, CX, DX as data registers.
>
> At least on the earlier machines, the opcode definitely favored the data
> register for arithmetic and the address registers for addressing.

The 68K series has (had?) distinct address and data registers
(A0..A7, D0..D7).  A7 is the stack pointer.

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips Healthcare
void Void(void) { Void(); } /* The recursive call of the void */

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Trick to knowing hex address alignment? dfs <nospam@dfs.com> - 2020-10-09 20:11 -0400
  Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-09 18:43 -0600
    Re: Trick to knowing hex address alignment? dfs <nospam@dfs.com> - 2020-10-09 22:14 -0400
  Re: Trick to knowing hex address alignment? Kaz Kylheku <793-849-0957@kylheku.com> - 2020-10-10 01:10 +0000
    Re: Trick to knowing hex address alignment? dfs <nospam@dfs.com> - 2020-10-09 22:15 -0400
  Re: Trick to knowing hex address alignment? "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2020-10-10 01:30 -0400
    Re: Trick to knowing hex address alignment? BGB <cr88192@gmail.com> - 2020-10-10 01:30 -0500
      Re: Trick to knowing hex address alignment? "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2020-10-12 16:58 -0400
        Re: Trick to knowing hex address alignment? BGB <cr88192@gmail.com> - 2020-10-14 16:04 -0500
  Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-10 18:31 +0200
    Re: Trick to knowing hex address alignment? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-10-10 09:46 -0700
      Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-10 19:50 +0200
        Re: Trick to knowing hex address alignment? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-10-10 18:45 +0000
          Re: Trick to knowing hex address alignment? James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-10-10 15:05 -0400
        Re: Trick to knowing hex address alignment? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2020-10-10 12:34 -0700
          Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-11 08:10 +0200
            Re: Trick to knowing hex address alignment? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-10-11 02:29 -0700
              Re: Trick to knowing hex address alignment? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-10-11 12:08 +0100
              Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-11 13:13 +0200
                Re: Trick to knowing hex address alignment? Richard Damon <Richard@Damon-Family.org> - 2020-10-11 15:06 -0400
              Re: Trick to knowing hex address alignment? James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-10-11 15:27 -0400
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 07:18 +0200
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 08:19 +0200
                Re: Trick to knowing hex address alignment? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-10-12 00:43 -0700
                Re: Trick to knowing hex address alignment? David Brown <david.brown@hesbynett.no> - 2020-10-12 12:03 +0200
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 13:14 +0200
                Re: Trick to knowing hex address alignment? Richard Damon <Richard@Damon-Family.org> - 2020-10-12 08:33 -0400
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 16:21 +0200
                Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-12 14:07 -0700
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 06:58 +0200
                Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-13 00:10 -0700
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 09:53 +0200
                Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-13 01:25 -0700
                Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-13 01:31 -0700
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 10:34 +0200
                Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-13 01:47 -0700
                Re: Trick to knowing hex address alignment? Kaz Kylheku <793-849-0957@kylheku.com> - 2020-10-13 15:39 +0000
                Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-13 16:16 -0700
                Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-12 14:32 +0000
                Re: Trick to knowing hex address alignment? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2020-10-12 07:13 -0700
                Re: Trick to knowing hex address alignment? David Brown <david.brown@hesbynett.no> - 2020-10-12 19:16 +0200
                Re: Trick to knowing hex address alignment? Vir Campestris <vir.campestris@invalid.invalid> - 2020-10-12 21:26 +0100
                Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-12 14:08 -0700
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 06:50 +0200
        Re: Trick to knowing hex address alignment? Vir Campestris <vir.campestris@invalid.invalid> - 2020-10-11 21:16 +0100
          Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 07:18 +0200
            Re: Trick to knowing hex address alignment? arnold@hooterville.invalid (Arnold Ziffel) - 2020-10-13 11:44 +0000
              Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 14:21 +0200
                Re: Trick to knowing hex address alignment? arnold@hooterville.invalid (Arnold Ziffel) - 2020-10-13 13:18 +0000
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 18:19 +0200
        Re: Trick to knowing hex address alignment? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2020-10-11 14:12 -0700
          Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 07:20 +0200
            Re: Trick to knowing hex address alignment? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2020-10-12 07:09 -0700
            Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-12 14:35 +0000
              Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 16:37 +0200
                Re: Trick to knowing hex address alignment? Bart <bc@freeuk.com> - 2020-10-12 15:51 +0100
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 17:07 +0200
                Re: Trick to knowing hex address alignment? Bart <bc@freeuk.com> - 2020-10-12 16:45 +0100
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 17:47 +0200
                Re: Trick to knowing hex address alignment? Bart <bc@freeuk.com> - 2020-10-12 17:05 +0100
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 06:46 +0200
                Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-12 14:19 -0700
                Re: Trick to knowing hex address alignment? arnold@hooterville.invalid (Arnold Ziffel) - 2020-10-13 11:48 +0000
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 14:22 +0200
                Re: Trick to knowing hex address alignment? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2020-10-13 06:25 -0700
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 18:20 +0200
                Re: Trick to knowing hex address alignment?, speciall Richard Damon <Richard@Damon-Family.org> - 2020-10-13 12:38 -0400
                Re: Trick to knowing hex address alignment?, speciall James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-10-13 12:51 -0400
                Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-12 11:11 -0600
                Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-12 18:50 +0000
                Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-12 13:03 -0600
                Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-12 19:30 +0000
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 06:47 +0200
                Re: Trick to knowing hex address alignment? arnold@hooterville.invalid (Arnold Ziffel) - 2020-10-13 11:52 +0000
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 14:23 +0200
                Re: Trick to knowing hex address alignment? Bart <bc@freeuk.com> - 2020-10-13 14:43 +0100
                Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-13 08:57 -0600
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 18:21 +0200
                Re: Trick to knowing hex address alignment? Bart <bc@freeuk.com> - 2020-10-13 17:38 +0100
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 19:03 +0200
                Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-13 11:20 -0600
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 19:23 +0200
                Re: Trick to knowing hex address alignment? Bart <bc@freeuk.com> - 2020-10-13 18:28 +0100
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 19:30 +0200
                Re: Trick to knowing hex address alignment? arnold@hooterville.invalid (Arnold Ziffel) - 2020-10-14 09:24 +0000
                Re: Trick to knowing hex address alignment? James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-10-14 09:35 -0400
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-15 09:29 +0200
                Re: Trick to knowing hex address alignment? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-10-13 10:24 -0700
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 19:31 +0200
                Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-13 14:47 -0700
                Re: Trick to knowing hex address alignment? Richard Damon <Richard@Damon-Family.org> - 2020-10-12 21:48 -0400
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 06:49 +0200
                Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-13 15:24 +0000
                Re: Trick to knowing hex address alignment? Richard Damon <Richard@Damon-Family.org> - 2020-10-13 12:32 -0400
                Re: Trick to knowing hex address alignment? Vir Campestris <vir.campestris@invalid.invalid> - 2020-10-13 21:55 +0100
                Re: Trick to knowing hex address alignment? Vir Campestris <vir.campestris@invalid.invalid> - 2020-10-13 22:00 +0100
                Re: Trick to knowing hex address alignment? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-10-13 14:13 -0700
                Re: Trick to knowing hex address alignment? David Brown <david.brown@hesbynett.no> - 2020-10-14 13:13 +0200
                Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-14 15:59 +0000
                Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-14 11:31 -0600
                Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-14 19:03 +0000
                Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-13 09:50 -0600
                Re: Trick to knowing hex address alignment? Kaz Kylheku <793-849-0957@kylheku.com> - 2020-10-13 17:41 +0000
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 20:07 +0200
                Re: Trick to knowing hex address alignment? Kaz Kylheku <793-849-0957@kylheku.com> - 2020-10-15 00:38 +0000
                Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-14 21:23 -0600
          Re: Trick to knowing hex address alignment? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-10-12 11:20 +0100
            Re: Trick to knowing hex address alignment? James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-10-12 10:19 -0400
    Re: Trick to knowing hex address alignment? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-10-10 15:42 -0700
      Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-11 13:14 +0200
        Re: Trick to knowing hex address alignment? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-10-11 14:11 -0700
          Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 07:20 +0200
            Re: Trick to knowing hex address alignment? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-10-12 00:42 -0700
              Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 13:16 +0200
                Re: Trick to knowing hex address alignment? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-10-12 07:22 -0700
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 16:23 +0200
              Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-12 14:35 +0000
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 16:40 +0200
                Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-12 14:09 -0700
          Re: Trick to knowing hex address alignment? David Brown <david.brown@hesbynett.no> - 2020-10-12 08:26 +0200
            Re: Trick to knowing hex address alignment? Öö Tiib <ootiib@hot.ee> - 2020-10-12 03:19 -0700
              Re: Trick to knowing hex address alignment? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-10-12 07:22 -0700
              Re: Trick to knowing hex address alignment? arnold@hooterville.invalid (Arnold Ziffel) - 2020-10-13 11:59 +0000
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 14:25 +0200
                Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-13 15:26 +0000
                Re: Trick to knowing hex address alignment? DFS <nospam@dfs.com> - 2020-10-13 11:33 -0400
                Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 18:23 +0200
    Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-11 09:47 -0600
  Re: Trick to knowing hex address alignment? Elias Schwerdtfeger <nachtwaechter@tamagothi.de> - 2020-10-10 18:45 +0200
    Re: Trick to knowing hex address alignment? Barry Schwarz <schwarzb@delq.com> - 2020-10-10 10:32 -0700
    Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-10 14:01 -0700

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