8 May
2000
8 May
'00
3:58 p.m.
In a message dated Mon, 8 May 2000 00:27:26 -0400 (EDT), Sean 'Captain
Napalm' Conner" <spc(a)armigeron.com> writes:
<< Again, to bring this back on topic, there have been plenty of operating
systems distributed in ROM---AmigaOS, QNX, OS-9 and the original MacOS were
all contained in ROM, were/are ROMmable and extensible. And all are older
than 10 years old. Even MS-DOS came in ROM format for some computers
(although I'm not sure if it ran out of ROM, or was copied to RAM before
running). >>
The Mac OS has never been fully contained in ROM. Starting with the Lisa in
1983 and the original Mac in 1984, Apple used a 64k ROM that contained GUI
program routines (the Macintosh ToolKit). These machines still had to boot a
floppy which made calls to the ROM.
Best,
David Greelish
Publisher
Classic Computing Press
www.classiccomputing.com
8 May
8 May
7:42 p.m.
David Greelish wrote:
In a message dated Mon, 8 May 2000 00:27:26 -0400
(EDT), Sean 'Captain
Napalm' Conner" <spc(a)armigeron.com> writes:
<< Again, to bring this back on topic, there have been plenty of operating
systems distributed in ROM---AmigaOS, QNX, OS-9 and the original MacOS were
all contained in ROM, were/are ROMmable and extensible. And all are older
than 10 years old. Even MS-DOS came in ROM format for some computers
(although I'm not sure if it ran out of ROM, or was copied to RAM before
running). >>
The Mac OS has never been fully contained in ROM. Starting with the Lisa in
1983 and the original Mac in 1984, Apple used a 64k ROM that contained GUI
program routines (the Macintosh ToolKit). These machines still had to boot a
floppy which made calls to the ROM.
Although this is true in a practical sense (especially because of the growth
of the OS), there is one exception I know of. On the original Mac Classic,
holding down Cmd-Option-X-O (the letter O) at boot time loads a small
version of the OS entirely from a disk image in ROM. (You can "Get Info" on
the disk and see an amusing note.) It may be System 6.0.2 or I could be
imagining that.
The new machines, on the other hand, load the "ROM" from disk and then write
protect the memory. Talk about going in the other direction...
-- Derek
9 May
9 May
7:15 a.m.
David Greelish wrote:
In a message dated Mon, 8 May 2000 00:27:26 -0400
(EDT), Sean 'Captain
Napalm' Conner" <spc(a)armigeron.com> writes:
<< Again, to bring this back on topic, there have been plenty of operating
systems distributed in ROM---AmigaOS, QNX, OS-9 and the original MacOS
were
all contained in ROM, were/are ROMmable and
extensible. (snip snip)
Although this is true in a practical sense (especially
because of the growth
of the OS), there is one exception I know of. On the original Mac Classic,
holding down Cmd-Option-X-O (the letter O) at boot time loads a small
version of the OS entirely from a disk image in ROM. (You can "Get Info" on
the disk and see an amusing note.) It may be System 6.0.2 or I could be
imagining that.
The new machines, on the other hand, load the "ROM" from disk and then write
protect the memory. Talk about going in the other direction...
Just like the original Amiga circa 1985, which loaded Kickstart off of disk
into write once protected RAM. Why?? Because the ROM code had not yet been
finalized when the computer was put on the market.
Another fine example of how marketing guys try to BS electrons . . .
Gary Hildebrand
-- Derek
3:34 a.m.
Just like the original Amiga circa 1985, which loaded
Kickstart off of disk
into write once protected RAM. Why?? Because the ROM code had not yet been
finalized when the computer was put on the market.
Another fine example of how marketing guys try to BS electrons . . .
Also for many years to recently most "roms" were slower than the system
so moving the rom code to ram was a way to attain speed for rommed code.
This became critical when the 486/33 and faster machines came about.
It's handy too as overlays for bug fixes or additional drivers are
possible as well.
Allison
5:46 a.m.
> In a message dated Mon, 8 May 2000 00:27:26 -0400
(EDT), Sean 'Captain
> Napalm' Conner" <spc(a)armigeron.com> writes:
>
> << Again, to bring this back on topic, there have been plenty
> of operating systems distributed in ROM---AmigaOS, QNX, OS-9
> and the original MacOS were all contained in ROM, were/are
> ROMmable and extensible. (snip snip)
Just like the original Amiga circa 1985, which loaded
Kickstart off of disk
into write once protected RAM. Why?? Because the ROM code had not yet been
finalized when the computer was put on the market.
Another fine example of how marketing guys try to BS
electrons . . .
Well, exactly the same happened to the _very_ first Atari STs.
The ROM contained only a boot loader and the TOS/GEM had to be
loaded from Disk. In fact this is also the reason why the RAM
got doubbled (by piggy pack chips) from 256K to 512K for the
260 and 512K to 1 Meg on the 520, corrupting the naming scheme.
This phase did last only about 3 Month, so a boot ROM ST is
quite a collectabe thing, especialy since most got updated.
Servus
Hans
--
VCF Europa am 28./29. April 2001 in Muenchen
http://www.vintage.org/vcfe
http://www.homecomputer.de/vcfe
9:59 a.m.
On Tue, May 09, 2000 at 10:15:28AM -0600, Derek Peschel wrote:
Just like the original Amiga circa 1985, which loaded
Kickstart off of disk
into write once protected RAM. Why?? Because the ROM code had not yet been
finalized when the computer was put on the market.
IIRC, the documentation consistantly referred to it as "ROM" even though that
was actually true on 0% of the machines shipping at the time. Then again,
unless I'm confusing it with the C64, the manuals consistantly misspelled
"kernel" so they were obviously pretty sloppy (unless they meant it as
an acronym for something). So we always talked about making calls to the
"kern-AL".
Geez, remember the scam that Commodore pulled with the programming
documentation? It wasn't ready at the time the machines finally shipped, and
when they eventually did get the docs together, they decided that they would
ship the first printing only to suckers who paid lots extra to be certified
Amiga developers, or some such BS. Regular folks who had already paid for
the documentation had to wait *months* before they actually received it.
John Wilson
D Bit
9:39 a.m.
David Greelish wrote:
The Mac OS has never been fully contained in ROM.
Starting with the Lisa in
1983 and the original Mac in 1984, Apple used a 64k ROM that contained GUI
program routines (the Macintosh ToolKit). These machines still had to boot a
floppy which made calls to the ROM.
The Lisa only had 16K of ROM, which did NOT contain anything but a
bootstrap loader and diagnostics. The Lisa operating system and
applications did not make any calls into the ROM, with the possible
exception of one function to set MMU registers. Macintosh software
certainly did not make any calls to the Lisa ROM, even on Lisas that
were sold under the name "Macintosh XL".
In the original Macintosh (64K ROM, 128K RAM), the OS was *almost*
entirely contained in ROM. The System file primarily contained fonts,
desk accessories, defprocs, and bug fixes. It was in fact possible
to write Macintosh applications that could be booted directly with no
System file, yet take full advantage of the Macintosh "OS".
The Macintosh OS has gone through multiple cycles of adding large
chunks of new functionality to the System file, then moving those
pieces into ROM. Unfortunately when the code gets moved into ROM,
it doesn't usually get removed from the System file, because it still
is needed for older Macs since Apple typically does not offer ROM
upgrades.
With System 7.5 (or was it 7.1), the size of the System file was
getting sufficiently out of hand that Apple moved a lot of platform-
specific code into "System Enablers".
Nowdays Macs don't have *any* of the OS in ROM; they use the OpenBoot
firmware to load the entire OS from disk.
8:20 p.m.
On Tue, May 09, 2000 at 06:39:18PM -0000, Eric Smith wrote:
The Macintosh OS has gone through multiple cycles of
adding large
chunks of new functionality to the System file, then moving those
pieces into ROM. Unfortunately when the code gets moved into ROM,
it doesn't usually get removed from the System file, because it still
is needed for older Macs since Apple typically does not offer ROM
upgrades.
I may have this wrong, but I remember being told that this meant having a
pretty complicated boot process where the ROM versions of various routines
could be replaced by a newer version off the disk, and that the amount of
code that had to be loaded from disk was sort of proportional to the age of
the computer. And supposedly this meant that a generic (works on any machine)
boot disk didn't have much free space, but if you (somehow) pared it down
to have only the patches required for your particular computer (instead of
all possible Macs throughout history) you could have a lot more space on
the disk. Sound right?
Wasn't there some point where they dropped support for the early Macs with
less ROM (64 K vs. 128 K or something??????), or am I making that up? If so,
was it just because thin Macs didn't have space for the bloat, or was there
really something wrong with what was in ROM that was beyond help?
John Wilson
D Bit
10:16 p.m.
John Wilson wrote:
Yes, because the ROM is largely made up of resources (i.e., the things you
can edit with ResEdit). The system file on disk is largely made up of
resources too. This may not be so true now as it was (and ResEdit hasn't
been updated in a long time).
On Tue, May 09, 2000 at 06:39:18PM -0000, Eric Smith
wrote:
The Macintosh
OS has gone through multiple cycles of adding large
chunks of new functionality to the System file, then moving those
pieces into ROM. Unfortunately when the code gets moved into ROM,
it doesn't usually get removed from the System file, because it still
is needed for older Macs since Apple typically does not offer ROM
upgrades.
I may have this wrong, but I remember being told that this meant having a
pretty complicated boot process where the ROM versions of various routines
could be replaced by a newer version off the disk, but if you
(somehow) pared it down
to have only the patches required for your particular computer (instead of
all possible Macs throughout history) you could have a lot more space on
the disk. Sound right?
Basically, except that the whole thing got an order of magnitude more
complicated after Ssytem 7 came out. Systems 8 and 9 made things even more
complicated and OS X will probably _really_ stir things up. The ROMs on
newer machiens have gone though a lot of changes too; after a certain point
they checked to see if you were booting with System 7 or later and put up an
error if you weren't. I think you can get around this (I've seen it once)
but I'm not sure how.
It's not easy these days to make a universal boot disk. Anyway, it would
have to be a Zip cartridge or CD-ROM (or some other large-capacity medium)
now.
Wasn't there some point where they dropped support
for the early Macs with
less ROM (64 K vs. 128 K or something??????), or am I making that up? If so,
was it just because thin Macs didn't have space for the bloat, or was there
really something wrong with what was in ROM that was beyond help?
I don't know. The issues of (lack of) guaranteed backward compatibility,
in-depth documentation about the OS and ROM, upgradability of the ROMs, and
the possibility of using other OSs are all "knee-jerk reaction" issues to
me. In other words, I don't know the answers, but I suspect they are bad
and gripe accordingly. The documentation I've seen is largely out of date.
The Mac architecture has gone through a large number of changes (some small,
some big). PCI and Open Firmware are promising developments in some ways.
(especially regarding the use of other OSs), however.
I'm a happy Mac user but really out-of-touch with Apple or with Mac
development. Maybe Eric knows more. Eric?
-- Derek
10 May
10 May
11:03 a.m.
John Wilson <wilson(a)dbit.dbit.com> wrote:
Wasn't there some point where they dropped support
for the early Macs with
less ROM (64 K vs. 128 K or something??????), or am I making that up? If so,
was it just because thin Macs didn't have space for the bloat, or was there
really something wrong with what was in ROM that was beyond help?
They just got tired of supporting it.
By now they've dropped support for all 68K Macintoshes, and even the
early PowerPC models.
8834
days inactive
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9 comments
6 participants
participants (6)
-
allisonp＠world.std.com -
dpeschel＠eskimo.com -
eric＠brouhaha.com -
Hans.Franke＠mch20.sbs.de -
Historical＠aol.com -
wilson＠dbit.dbit.com