Hi,
On Mon, 19 Apr 1999 Jason wrote:
> I'm getting a couple of IBM optical drives (one internal, one external).
> From the description, they have MCA controller cards. My question is:
> Would there be a way to run the internal one from an ISA controller? Maybe
> the question should be where can I get an ISA controller for an IBM optical
> drive?
There are optical drives and optical drives... (read on)
> My other question is if Optical disks are re-writable? I've talked to two
> people, and one of them says that Optical disks aren't re-writable,
> mangeto-optical disks are. The other person said that no optical disk is
> re-writable, and that only floptical disks are (isn't that a form of optical
> disk?)
The other person is wrong. MO disks are rewriteable, and come to think of it
some other types of optical media are, including CD-RW, DVD-RAM and PD.
As I understand it, flopticals are just like floppies but use a laser to assist
in positioning the drive head. I wouldn't call these optical disks. (I bet
they're as reliable as Windows too.)
There are various types of optical disk, of which magneto-optical ("MO") disks
are one. MO disks are rewritable (like 10 million times), and are about the
best -- in terms of media reliability and longevity -- true random-access
rewriteable removable storage there is. And the media is much cheaper than
Zip, Jaz etc. disks.
There are 3.5" and 5.25" MO disks. 5.25" disks are also available in write-once
varieties, but the drives themselves can handle both. (In fact the write-once
disks are physically almost identical to the normal ones. The drive reads a
flag to see that the disk should be write-only, and the drive firmware handles
preventing writes to sectors that have already been written.)
Anyway, I'll elaborate on my previous comment. IBM certainly used to sell SCSI
128MB 3.5" MO drives (circa 1992?). If you are getting a pair of these, using
them will be no problem, assuming you have a SCSI controller.
Earlier than that, IBM sold at least one other type of optical drive, which was
a WORM (write once read many) drive. As the WORM acronym suggests, disks for
the 3363 are not rewritable. They hold about 200MB each. The model 3363 drive
was introduced in 1987, and I picked one up recently, along with two MCA
controllers. The 3363 uses a custom interface. I want to get hold of an ISA
controller to use with the 3363. I found someone who has one for sale, sold as
seen for US$25. Too much for me.
If you are getting a couple of 3363 drives (which are big, heavy beasts), they
will be more of a curiosity than anything else.
They use proprietary disks, which -- if you can still get them from IBM at all
-- probably cost about $90 each. I have four still-sealed ones, but I'm
hanging onto them in the hope that I eventually get an ISA controller card for
my 3363...
Plug: check out my Amiga Magneto-Optical Drive FAQ. This contains some info on
why MO drives are cool, and a fair amount of details about using them with
Amiga computers and well as non-platform-specific things. The URL is
http://home.freeuk.net/markk/Amiga_MO_FAQ/main.html
-- Mark
Received on Thu Apr 29 1999 - 10:55:19 BST