abe@wet.UUCP (Dave Abercrombie) (06/28/91)
I am interested in putting OS/2 on my Micronics 386 system,
but I already have two operating systems on my disk, and
wonder what I will need to do to add OS/2. Some specific
questions follow a description of my situation and goals.
I have a 100 megabyte IDE drive with four partitions:
0 = MS-DOS 5.0 (bootable)
1 = MS-DOS 5.0 filesytem
2 = Coherent filesystem
3 = Coherent (bootable)
Coherent is a $100 UNIX clone; the current version is a
small memory model 80286 multi-tasking, multi-user OS. The
80386 large memory model version will be released in several
months (we all hope! - see comp.os.coherent). Coherent's
installation put a small routine in the hard drive's master
boot block. This routine pauses at the start of the boot
process to ask which partition I want to boot from
(Coherent's version of fdisk allows one to mark no
partitions as "active" i.e., no default boot partition).
A response of 0 gets me DOS, and 3 gets me Coherent. Of
course, responses 1, 2, 4, 5, 6, & 7 don't do much for me!
I think it's kind of nifty!
I have a vague plan to get another IDE drive (my Phoenix
BIOS supports two drives), and partition it into OS/2 HPFS
and more Coherent. Questions:
1. Can I install OS/2 on a second drive as described
and not mess up my master boot block on the first
drive (so that I can still choose an operating
system at boot time)? The MS-DOS 5.0 upgrade trashed
my master boot block - I needed to reinstall it.
2. If OS/2 installation doesn't mess up my master boot block
(or I subsequently reinstall it) does it seem like I will
able to choose between the three operating systems at
boot time? I realize this might be difficult to answer.
3. What is the OS/2 "dual-boot" feature I have read a bit
about, and how does it relate to my goals? I gather that
it operates differently than Coherent's master boot
routine.
4. HPFS sounds neat: is there any reason I might not be able
to use it in my proposed configuration?
5. Are the answers to any of these questions likely to
change with the release of OS/2 2.0? I am inclined
to wait until then, rather than install 1.3 now and
upgrade to 2.0 later (the MS-DOS upgrade was more
difficult than I imagined).
6. Am I crazy, or does this all sound like fun?kwb@betasvm2.vnet.ibm.com (Ken Borgendale) (06/28/91)
OS/2 1.x will only install and boot from the C drive. This is the first partition on the disk in HPFS or DOS primary format. If you already have the partitions defined, and the disks formatted before calling OS/2 install, and tell it not to do so as part of install, then the partition table and master book record will be unchanged as the result of the OS/2 install. If you have DOS 5.0 on your C drive before installing OS/2 1.2 or OS/2 1.3, dual boot will be enabled, which allows you to select DOS or OS/2 by running a program before booting. (Personally I leave my system in OS/2 mode and boot DOS from a diskette, but that is a personal preference). OS/2 1.x works fine with the Coherent master boot record. OS/2 2.0 will come with an optional multi-boot capability. If you select this option, it will rewrite your master book record. Thus you will probably not be able to boot coherent after selecting this option. However, if you select this option, you can boot OS/2 from any drive. This is similar to the problems between Coherent and SCO Unix who both update the master book record. Perhaps the various PC operating systems can get together to produce a multi operating system master boot record which also allows each of them to load their bootstrap. This was the original aim of the partition table with the active bit. Ken Borgendale (standard disclaimers since I am only a little obnoxious)
wbonner@yoda.eecs.wsu.edu (Wim Bonner) (06/29/91)
In article <2642@wet.UUCP> abe@wet.UUCP (Dave Abercrombie) writes: >3. What is the OS/2 "dual-boot" feature I have read a bit > about, and how does it relate to my goals? I gather that > it operates differently than Coherent's master boot > routine. Well, OS/2 Dual Boot is just that. It will only switch between two OS/s, and I believe it is designed specificly for DOS. Wim -- Wim Bonner wbonner@yoda.eecs.wsu.edu 27313853@wsuvm1.csc.wsu.edu