2 megs or not 2 megs? :-)
Aquarius
Well, I've got a 286, and I had some problems installing Minix on it. I
posted about this before, but I got confused about the answer, so I
thought I'd lay out the problem in a consistent manner.
My 286 has 2 megs of XMS[1], not EMS (since you can't get EMS on a 286).
When Minix asks in the install how much memory I've got, I tell it
2688K, which is how much the BIOS thinks I have.
However, I seem to recall someone saying that Minix can't use XMS.
Does this mean I am fated to attempt to run the whole lot in 640K?
I've seen a couple of suggestions for how to increase memory, the main
one being to set processor=86 (which I presumably do in the boot monitor
once I've booted from the ROOT+USR disk, before I start the install?)
Can this not be fixed?
Can I set up the extra 2 MB as a ramdisk or something?
Would I be advised to use the XT tinyroot to boot and install, or should
I be using the normal i86 ROOT?
Aquarius
[1] nb: I can never remember which is expanded and which is extended, so
please call it XMS :-)
--
o |~> --------------------------------------------------------------
| (\._[~] aqua...@cryogen.com | Beer: it's not just for breakfast
|~|) |~~| "The grand plan that is Aquarius proceeds apace" - Ronin, FM
------------------------------------------------------------------------
Julien Oster
>>>>> "Aquarius" == Aquarius <A...@btinternet.com> writes:
> Well, I've got a 286, and I had some problems installing Minix on it. I
> posted about this before, but I got confused about the answer, so I thought
> I'd lay out the problem in a consistent manner.
> My 286 has 2 megs of XMS[1], not EMS (since you can't get EMS on a 286).
AFAIK, a 286 can only get _EMS_, but not _XMS_! EMS became obsolete over the
years, because the 386 can use XMS which is faster and better.
> When Minix asks in the install how much memory I've got, I tell it 2688K,
> which is how much the BIOS thinks I have. However, I seem to recall someone
> saying that Minix can't use XMS.
But EMS. Your 286 should have EMS, not XMS.
> Does this mean I am fated to attempt to run the whole lot in 640K? I've
> seen a couple of suggestions for how to increase memory, the main one being
> to set processor=86 (which I presumably do in the boot monitor once I've
> booted from the ROOT+USR disk, before I start the install?)
You're problem is not a problem, since you're having EMS and not XMS :) Or am
I thinking wrong?
> [1] nb: I can never remember which is expanded and which is extended, so
> please call it XMS :-)
Same with me :) I can never remember which one is expanden and which is
extended, but I know what XMS is and what EMS is :)
--
CUl8r, Julien Oster
der, der nicht "ist" sondern "sind",
aber in rekursiver Wiederkehr.
Will Rose
Aquarius (A...@btinternet.com) wrote:
: Well, I've got a 286, and I had some problems installing Minix on it. I
: posted about this before, but I got confused about the answer, so I
: thought I'd lay out the problem in a consistent manner.
: My 286 has 2 megs of XMS[1], not EMS (since you can't get EMS on a 286).
: When Minix asks in the install how much memory I've got, I tell it
: 2688K, which is how much the BIOS thinks I have.
: However, I seem to recall someone saying that Minix can't use XMS.
: Does this mean I am fated to attempt to run the whole lot in 640K?
: I've seen a couple of suggestions for how to increase memory, the main
: one being to set processor=86 (which I presumably do in the boot monitor
: once I've booted from the ROOT+USR disk, before I start the install?)
No, given that its a fairly standard 286, Minix should see all the
memory; what does it say when it boot? There should be a sign-on
saying how much memory there is, and how much is used by the ram disk.
I don't know about the XMS standard; 8086s used expanded memory, and
286s used extended memory, EMS. You could make EMS look like expanded
memory with the right driver under MSDOS. Minix will use extended
memory with no problems, but won't use expanded memory with a patch,
and then only for the ramdisk.
Kees J Bot
In article <ufyay65...@fuzzy.cubenet.de>,
>> posted about this before, but I got confused about the answer, so I thought
>> I'd lay out the problem in a consistent manner.
>
>> My 286 has 2 megs of XMS[1], not EMS (since you can't get EMS on a 286).
>
>years, because the 386 can use XMS which is faster and better.
Once upon a time when I was young and stupid I needed a name for the
extended memory size variable in the Boot Monitor. So instead of simply
using "extsize", I decided to make it look as if I knew something, so
it became "emssize".
Later I came to know that EMS = Expanded Memory System, and XMS =
Extended Memory System. Alas the name "emssize" is now ingrained into
both the Boot Monitor and the kernel, which is not something you can
easily change. So the confusion continues.
--
Kees J. Bot, Systems Programmer, Dept. Math&CS, Vrije Universiteit Amsterdam
Minix: http://www.cs.vu.nl/pub/minix/ ftp://ftp.cs.vu.nl/pub/minix/
Minix-vmd: http://Minix-vmd.cs.vu.nl/ ftp://Minix-vmd.cs.vu.nl/
Jared Ryan
In article <1d65pdf.cx3...@host5-99-48-182.btinternet.com>,
A...@btinternet.com says...
>My 286 has 2 megs of XMS[1], not EMS (since you can't get EMS on a 286).
A 286 can access either eXtended or Expanded memory. A 286 can access up to
16Mb including the first 1Mb, which includes the DOS 640K and the 384K
normally reserved for ROMs and the like.
Expanded memory can only be addressed with a memory manager, a driver that's
loaded after DOS. The Lotus-Intel-Microsoft (LIM) EMS 4.0 spec became
standard. Systems so equipped can have up to 32Mb of EMS, in theory.
eXtended memory can only be accessed with the 286 in protected mode.
Protected mode on the 286 is somewhat crippled; Intel designed no method for
knocking the system *out* of protected mode. To switch back to real mode, the
system needs to be reset - which some programs actually do, using a spare pin
on the keyboard interface chip. This is all related to the A20 line you
sometimes see mentioned.
--
- Jared Ryan [jry...@csi.com]
http://surf.to/el-camino/ ~~~~~~~ ICQ # 8457412
"American by birth, Texan by the grace of God."