Re: Hard Drives Partition

[nathan@cco.caltech.edu (Nathan Mates)]

In article <3l4de7$3dj@freenet.vancouver.bc.ca>,
Gavin Fung <gfung@freenet.vancouver.bc.ca> wrote:
>Is it possible to partition the hard drive for several different
>format, ie. HFS, ProDOS, and MSDOS.  And to have all the different
>computers connect to the same drive.  I want to connect my IBM
>laptop and my Apple //GS to the same hard drive.  I would like one
>partition for my //gs to boot off, and another for the IBM if possible.
>Would this be possible?  Please email me the answer.

1) HDs can be partitioned with multiple different formats. I have
5 ProDOS partitions, and 1 HFS partition on my 235MB HD.

2) SCSI is not normally designed to be accessed by multiple systems at
once. It's something called 'bus mastering,' where you have multiple
controllers for one drive, and they arbitrate between themselves for
access. This really isn't done too much anyhow, so I don't believe
that any Apple II SCSI controllers support this. (I could be wrong,
though)

3) Each SCSI device has some 'boot blocks' if it is to be booted by
one system, I believe. The RamFAST/SCSI uses these, I believe, to
write out the mapping of slots/drive to paritions, etc.

   From these 3, making multiple (differently formatted) partitions on
a HD is no problem, but trying to hook it in to multiple computers
simultaneously, or trying to boot it off various computers one at a
time is out. What you could do is hook up a drive to multiple
computers one at a time, and write stuff to it. How the IBM end would
like non-MSDOG paritions would also be touchy, but doable. (Don't put
anything non-backed up important stuff on the HD until you've gotten
this working successfully).

   You would have to pick one computer that could boot off the drive;
the other would have to use it just like an external HD. Since almost
all laptops have their own HD, this would probably be the best thing
to do. To use it on multiple systems, you'd have to power down both,
and change cables.

Nathan Mates
--
<*> Nathan Mates http://www.ugcs.caltech.edu/~nathan/      <*>
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