Groups > alt.folklore.computers > #234632

Re: CMS, Self-hosting and the 6502

From	Lynn Wheeler <lynn@garlic.com>
Newsgroups	alt.folklore.computers
Subject	Re: CMS, Self-hosting and the 6502
Date	2026-04-06 07:39 -1000
Organization	Wheeler&Wheeler
Message-ID	<875x64ugxl.fsf@localhost> (permalink)
References	(4 earlier) <10qucqd$cs9$2@gal.iecc.com> <10qv31u$1l5fk$3@paganini.bofh.team> <10qv7t7$1re07$2@dont-email.me> <10qvlrb$1uf62$2@dont-email.me> <10r0g2r$25l0l$1@dont-email.me>

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Peter Flass <Peter@Iron-Spring.com> writes:
> 360 was all position-independent. In theory there were no absolute
> addresses, everything was base-displacement. Change the base register
> and Bob's your uncle. Unfortunately there were a couple of gotchas,
> address constants being the worst. Also the small range of addresses
> available from a single base became limiting as programs got larger.

OS/360, etc ... large programs required addresses ... on disk the
addresses were relative to position within the program ... but loaders
were required to modify the addresses to fixed real addresses in real
storage.

tss/360 and support for multiple virtual memory address spaces and
shared segments wanted the image in memory be exactly the same as the
image on disk ... w/o requiring all addresses to be modified as the
whole program was swapped into real memory ... but allowing for demand
paged in w/o requiring for executable images to be preloaded (and
addresses modified for their loaded position). Also not requiring for
shared segments to have the same addresses in different virtual
addresses spaces.

OS/360 MVT in transition to VS2/MVS kept the OS/360 preloading/swapping
in executable image and changing location addresses (making the affected
pages of the executing image changed). TSS/360 just mapped portions of
the virtual address space to the executable image on disk ... and in
case of shared segments could just change segment table pointer to that
of same shared segment concurrently in use by multiple other virtual
address spaces.

W/o location independence and requiring executable image to be otherwise
preloaded to have address constants to be modified to their executing
position ... would have required every executing program image to have
unique address across the whole system (or have restricted only have
certain executables to be concurrently mapped into the same address
space).

That is what got me providing page-mapped filesystem for CMS ... and CMS
was using OS/360 compilers and assemblers which assumed address
constants had to be modified as executables were loaded (had to fiddle
the programs so the executables images on disk were identical to
the same as executable images mapped to virtual address spaces).

-- 
virtualization experience starting Jan1968, online at home since Mar1970

Thread

Re: Self-hosting and the 6502 Lev <thresh3@fastmail.com> - 2026-03-30 19:12 +0000
  Re: Self-hosting and the 6502 David Wade <g4ugm@dave.invalid> - 2026-03-30 21:01 +0100
    Re: Self-hosting and the 6502 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-03-30 21:02 +0000
    Re: Self-hosting and the 6502 John Levine <johnl@taugh.com> - 2026-03-31 00:44 +0000
      Re: Self-hosting and the 6502 antispam@fricas.org (Waldek Hebisch) - 2026-03-31 19:46 +0000
        Re: TSS, Self-hosting and the 6502 John Levine <johnl@taugh.com> - 2026-03-31 20:48 +0000
          Re: TSS, Self-hosting and the 6502 antispam@fricas.org (Waldek Hebisch) - 2026-04-01 23:23 +0000
            Re: TSS, Self-hosting and the 6502 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-04-02 10:53 +0000
              Re: TSS, Self-hosting and the 6502 Peter Flass <Peter@Iron-Spring.com> - 2026-04-02 07:29 -0700
                Re: TSS, Self-hosting and the 6502 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-04-02 16:58 +0000
                Re: TSS, Self-hosting and the 6502 Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-04-02 20:34 +0000
                Re: TSS, Self-hosting and the 6502 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-04-02 20:53 +0000
        Re: Self-hosting and the 6502 Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-03-31 21:01 +0000
        Re: Self-hosting and the 6502 Lynn Wheeler <lynn@garlic.com> - 2026-04-03 16:53 -1000
          Re: Self-hosting and the 6502 Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-04-04 03:57 +0000
            Re: Self-hosting and the 6502 Peter Flass <Peter@Iron-Spring.com> - 2026-04-04 07:37 -0700
              Re: Self-hosting and the 6502 John Levine <johnl@taugh.com> - 2026-04-04 21:55 +0000
                Re: Self-hosting and the 6502 Peter Flass <Peter@Iron-Spring.com> - 2026-04-04 15:48 -0700
                Re: ancient time sharingSelf-hosting and the 6502 John Levine <johnl@taugh.com> - 2026-04-05 02:27 +0000
              Re: Self-hosting and the 6502 Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-04-04 22:03 +0000
                Re: Self-hosting and the 6502 Lynn Wheeler <lynn@garlic.com> - 2026-04-04 12:31 -1000
            Re: Self-hosting and the 6502 Lynn Wheeler <lynn@garlic.com> - 2026-04-04 07:40 -1000
            Re: Self-hosting and the 6502 Lars Poulsen <lars@beagle-ears.com> - 2026-04-04 13:44 -0700
              Re: Self-hosting and the 6502 (VSCP) ted@loft.tnolan.com (Ted Nolan <tednolan>) - 2026-04-05 20:23 +0000
        Re: Self-hosting and the 6502 Lynn Wheeler <lynn@garlic.com> - 2026-04-04 12:53 -1000
          Re: Self-hosting and the 6502 Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-04-04 23:44 +0000
            Re: Self-hosting and the 6502 David Wade <g4ugm@dave.invalid> - 2026-04-05 09:29 +0100
              Re: CMS, Self-hosting and the 6502 John Levine <johnl@taugh.com> - 2026-04-05 19:22 +0000
                Re: CMS, Self-hosting and the 6502 Lynn Wheeler <lynn@garlic.com> - 2026-04-05 14:30 -1000
                Re: CMS, Self-hosting and the 6502 Peter Flass <Peter@Iron-Spring.com> - 2026-04-05 20:02 -0700
                history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Kragen Javier Sitaker <kragen@canonical.org> - 2026-09-11 09:05 -0300
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Jeroen Belleman <jeroen@nospam.please> - 2026-09-11 16:49 +0200
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Andy Burns <usenet@andyburns.uk> - 2026-09-11 15:58 +0100
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Kragen Javier Sitaker <kragen@canonical.org> - 2026-09-11 13:38 -0300
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Jeroen Belleman <jeroen@nospam.please> - 2026-09-11 19:41 +0200
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Andy Burns <usenet@andyburns.uk> - 2026-09-11 19:18 +0100
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Jeroen Belleman <jeroen@nospam.please> - 2026-09-11 21:27 +0200
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) scott@slp53.sl.home (Scott Lurndal) - 2026-09-11 21:13 +0000
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Lynn Wheeler <lynn@garlic.com> - 2026-09-12 14:47 -1000
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Lars Poulsen <lars@beagle-ears.com> - 2026-09-13 15:02 -0700
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Peter Flass <Peter@Iron-Spring.com> - 2026-09-13 16:27 -0700
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Lynn Wheeler <lynn@garlic.com> - 2026-09-14 15:11 -1000
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-09-15 04:19 +0000
                Computes at CERN (Re: history of ASCII and IBM ratfucking, and the VAX ) Lars Poulsen <lars@beagle-ears.com> - 2026-09-13 14:56 -0700
                Re: Computes at CERN (Re: history of ASCII and IBM ratfucking, and the VAX ) Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-09-15 04:10 +0000
                Re: Computes at CERN (Re: history of ASCII and IBM ratfucking, and the VAX ) Lars Poulsen <lars@beagle-ears.com> - 2026-09-15 05:46 -0700
                Re: Computes at CERN (Re: history of ASCII and IBM ratfucking, and the VAX ) Peter Flass <Peter@Iron-Spring.com> - 2026-09-15 07:51 -0700
                Re: Computes at CERN (Re: history of ASCII and IBM ratfucking, and the VAX ) Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-09-15 23:22 +0000
                Re: Computes at CERN (Re: history of ASCII and IBM ratfucking, and the VAX ) Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-09-15 23:13 +0000
                Re: Computes at CERN (Re: history of ASCII and IBM ratfucking, and the VAX ) Jeroen Belleman <jeroen@nospam.please> - 2026-09-15 16:48 +0200
                Re: Computes at CERN (Re: history of ASCII and IBM ratfucking, and the VAX ) John Ames <commodorejohn@gmail.com> - 2026-09-15 08:19 -0700
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Lynn Wheeler <lynn@garlic.com> - 2026-09-12 14:13 -1000
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Lynn Wheeler <lynn@garlic.com> - 2026-09-12 14:12 -1000
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Kragen Javier Sitaker <kragen@canonical.org> - 2026-09-13 14:02 -0300
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Andy Burns <usenet@andyburns.uk> - 2026-09-13 18:55 +0100
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Andy Burns <usenet@andyburns.uk> - 2026-09-13 19:03 +0100
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Andy Burns <usenet@andyburns.uk> - 2026-09-13 19:07 +0100
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Peter Flass <Peter@Iron-Spring.com> - 2026-09-13 16:21 -0700
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Nuno Silva <nunojsilva@invalid.invalid> - 2026-09-14 00:37 +0100
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Peter Flass <Peter@Iron-Spring.com> - 2026-09-13 20:56 -0700
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-09-14 04:12 +0000
                Re: history of ASCII and IBM ratfucking, and the VAX (was Re: CMS, Self-hosting and the 6502) Lynn Wheeler <lynn@garlic.com> - 2026-09-14 15:06 -1000
                Re: CMS, Self-hosting and the 6502 antispam@fricas.org (Waldek Hebisch) - 2026-04-06 01:42 +0000
                Re: CMS, Self-hosting and the 6502 Peter Flass <Peter@Iron-Spring.com> - 2026-04-05 20:05 -0700
                Re: CMS, Self-hosting and the 6502 Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-04-06 07:03 +0000
                Re: CMS, Self-hosting and the 6502 Lynn Wheeler <lynn@garlic.com> - 2026-04-05 22:19 -1000
                Re: CMS, Self-hosting and the 6502 Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-04-06 08:20 +0000
                Re: CMS, Self-hosting and the 6502 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-04-06 12:03 +0000
                Re: CMS, Self-hosting and the 6502 Peter Flass <Peter@Iron-Spring.com> - 2026-04-06 07:30 -0700
                Re: CMS, Self-hosting and the 6502 Lynn Wheeler <lynn@garlic.com> - 2026-04-06 07:39 -1000
                Re: CMS, Self-hosting and the 6502 Peter Flass <Peter@Iron-Spring.com> - 2026-04-06 12:05 -0700
                Re: CMS, Self-hosting and the 6502 Lynn Wheeler <lynn@garlic.com> - 2026-04-06 17:41 -1000
                position-independent code (was Re: CMS, Self-hosting and the 6502) Kragen Javier Sitaker <kragen@canonical.org> - 2026-09-11 09:42 -0300
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) Lynn Wheeler <lynn@garlic.com> - 2026-09-12 15:12 -1000
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) John Levine <johnl@taugh.com> - 2026-09-13 01:57 +0000
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) Peter Flass <Peter@Iron-Spring.com> - 2026-09-12 21:14 -0700
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) legalize+jeeves@mail.xmission.com (Richard) - 2026-09-17 17:06 +0000
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) scott@slp53.sl.home (Scott Lurndal) - 2026-09-17 17:56 +0000
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) legalize+jeeves@mail.xmission.com (Richard) - 2026-09-18 14:08 +0000
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) Nuno Silva <nunojsilva@invalid.invalid> - 2026-09-18 19:29 +0100
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) John Ames <commodorejohn@gmail.com> - 2026-09-18 12:00 -0700
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-09-18 20:35 +0000
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) Andy Valencia <vandys@vsta.org> - 2026-09-17 11:32 -0700
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) James Dow Allen <user4353@newsgrouper.org.invalid> - 2026-09-13 07:31 +0000
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) Peter Flass <Peter@Iron-Spring.com> - 2026-09-13 07:45 -0700
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) John Levine <johnl@taugh.com> - 2026-09-13 16:50 +0000
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) Peter Flass <Peter@Iron-Spring.com> - 2026-09-13 16:18 -0700
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-09-15 04:21 +0000
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) scott@slp53.sl.home (Scott Lurndal) - 2026-09-15 14:33 +0000
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) Peter Flass <Peter@Iron-Spring.com> - 2026-09-15 07:37 -0700
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-09-15 23:35 +0000
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) Lynn Wheeler <lynn@garlic.com> - 2026-09-14 14:41 -1000
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) John Levine <johnl@taugh.com> - 2026-09-13 01:54 +0000
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) Kragen Javier Sitaker <kragen@canonical.org> - 2026-09-13 14:53 -0300
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) John Levine <johnl@taugh.com> - 2026-09-13 22:18 +0000
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) Peter Flass <Peter@Iron-Spring.com> - 2026-09-13 16:24 -0700
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-09-14 01:51 +0000
                Re: position-independent code (was Re: CMS, Self-hosting and the 6502) scott@slp53.sl.home (Scott Lurndal) - 2026-09-14 14:53 +0000
                Re: CMS, Self-hosting and the 6502 antispam@fricas.org (Waldek Hebisch) - 2026-04-06 19:21 +0000
                Re: CMS, Self-hosting and the 6502 David Wade <g4ugm@dave.invalid> - 2026-04-06 21:25 +0100
    Re: Self-hosting and the 6502 antispam@fricas.org (Waldek Hebisch) - 2026-03-31 02:32 +0000
      Re: Self-hosting and the 6502 Bill Findlay <findlaybill@blueyonder.co.uk> - 2026-03-31 04:06 +0100
      Re: Self-hosting and the 6502 David Wade <g4ugm@dave.invalid> - 2026-03-31 08:52 +0100
        Re: Self-hosting and the 6502 Bill Findlay <findlaybill@blueyonder.co.uk> - 2026-03-31 18:07 +0100
  Re: Self-hosting and the 6502 Peter Flass <Peter@Iron-Spring.com> - 2026-03-30 13:51 -0700
    Re: TSS arcana, Self-hosting and the 6502 John Levine <johnl@taugh.com> - 2026-03-31 00:58 +0000
      Re: TSS arcana, Self-hosting and the 6502 Peter Flass <Peter@Iron-Spring.com> - 2026-03-31 07:35 -0700
        Re: TSS arcana, Self-hosting and the 6502 Bob Eager <news0009@eager.cx> - 2026-03-31 14:54 +0000
          Re: TSS arcana, Self-hosting and the 6502 Peter Flass <Peter@Iron-Spring.com> - 2026-03-31 13:01 -0700
      Re: TSS arcana, Self-hosting and the 6502 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-03-31 22:14 +0000
        Re: TSS arcana, Self-hosting and the 6502 Bob Eager <news0009@eager.cx> - 2026-03-31 22:32 +0000
        Re: linkers, TSS arcana, Self-hosting and the 6502 John Levine <johnl@taugh.com> - 2026-04-01 02:06 +0000
          Re: linkers, TSS arcana, Self-hosting and the 6502 Bob Eager <news0009@eager.cx> - 2026-04-01 09:53 +0000
            Re: linkers, TSS arcana, Self-hosting and the 6502 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-04-01 16:07 +0000
              Re: linkers, TSS arcana, Self-hosting and the 6502 Bob Eager <news0009@eager.cx> - 2026-04-01 16:27 +0000
            Re: linkers, TSS arcana, Self-hosting and the 6502 John Levine <johnl@taugh.com> - 2026-04-01 16:10 +0000
            Re: linkers, TSS arcana, Self-hosting and the 6502 Andy Walker <anw@cuboid.co.uk> - 2026-04-01 17:15 +0100
              Re: linkers, TSS arcana, Self-hosting and the 6502 Bob Eager <news0009@eager.cx> - 2026-04-01 16:28 +0000
                Re: linkers, TSS arcana, Self-hosting and the 6502 scott@slp53.sl.home (Scott Lurndal) - 2026-04-01 16:48 +0000
                Re: linkers, TSS arcana, Self-hosting and the 6502 John Levine <johnl@taugh.com> - 2026-04-01 17:44 +0000
                Re: linkers, TSS arcana, Self-hosting and the 6502 Peter Flass <Peter@Iron-Spring.com> - 2026-04-01 14:21 -0700
              Re: linkers, TSS arcana, Self-hosting and the 6502 Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-04-01 20:40 +0000
                Re: linkers, TSS arcana, Self-hosting and the 6502 scott@slp53.sl.home (Scott Lurndal) - 2026-04-01 22:02 +0000
              Re: linkers, TSS arcana, Self-hosting and the 6502 Andy Walker <anw@cuboid.co.uk> - 2026-04-02 15:28 +0100
                Re: linkers, TSS arcana, Self-hosting and the 6502 scott@slp53.sl.home (Scott Lurndal) - 2026-04-02 15:36 +0000
                Re: linkers, TSS arcana, Self-hosting and the 6502 Andy Walker <anw@cuboid.co.uk> - 2026-04-02 17:15 +0100
                Re: linkers, TSS arcana, Self-hosting and the 6502 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-04-02 16:44 +0000
  Re: Self-hosting and the 6502 Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-03-30 21:30 +0000
    Re: Self-hosting and the 6502 David Wade <g4ugm@dave.invalid> - 2026-03-30 23:28 +0100
      Re: Self-hosting and the 6502 Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-03-30 23:36 +0000
        Re: Self-hosting and the 6502 John Ames <commodorejohn@gmail.com> - 2026-03-31 07:46 -0700
          Re: Self-hosting and the 6502 snipeco.2@gmail.com (Sn!pe) - 2026-03-31 15:54 +0100
          Re: Self-hosting and the 6502 Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-03-31 19:03 +0000
      Re: VM history, was Self-hosting and the 6502 John Levine <johnl@taugh.com> - 2026-03-31 01:04 +0000
        Re: VM history, was Self-hosting and the 6502 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-03-31 22:17 +0000
    Re: Self-hosting and the 6502 Peter Flass <Peter@Iron-Spring.com> - 2026-03-30 15:36 -0700
      Re: Self-hosting and the 6502 cross@spitfire.i.gajendra.net (Dan Cross) - 2026-03-31 22:19 +0000

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