#CDROMS alternate formats
13 messages in this thread
I am (hopefully) starting up a company that is based upon an alternate
operating system. Does anyone know how to go about contacting companies
that offer cdroms to offer or discuss with them converting their existing
cdroms into a format our native operating system can utilize? I imagine it
would take getting the original source information and then writing our
engine into it, but I am not the techie and don't much about how cdroms are
built and what type of errrr index engines drive them at the software level
etc…
Any leads or tips on books, contacts etc would be much appreciated!
Thanks, Victor
Most of (95%) the CD-ROMs available today use the same format ISO-9660. So
moving data around on CD-ROM is not a problem at all since most i if not
all important operating systems have CD-ROM support.
The problem comes when you want to use retrevial software on a platform
other than DOS. Since most of the CD roms currently available only support
DOS they only work on DOS.
This is still a problem that has yet to be solved in a fashion that is good
both to the consumer (end user) and the maker of CD-ROM discs. If you have
a specific need for a CD-ROM on a different platform contact the
author/manufacturer of the CD-ROM disc and see what their plans are for the
future.
With regard to tips on books, contacts etc. Just reading messages in this
forum should provide you with good information to find books and contacts
related to CD-ROM and its associated technology.
Albert, Thank you for that info. Could you explain to me what exactly the
ISO-9660 format is? Vic
ISO-9660 format is like MS-DOS format in a way since it describes the
directory structure and how files are located. Filenames in ISO-9660
(level 1) is 8.3 just like filenames are under MS-DOS.
THe previous standard before ISO on which ISO-9660 is based is the high
sierra format. If you want specifics on that you can download the files in
the lib here that detail the High Sierra format which is from 1986.
ISO-9660 was finished in 1988.
If you want me to clarify something in more detail feel free to ask me a
question.
Thank you for the info, this is really a learning experience for me. Ok, I
am under the impression that only dos machines can read dos made cdroms,
ie, unix os can't utilize a dos based cdrom because I was told, cdroms,
some of them that is, have some special type of index or coding that only
dos can get at and emulate, so a lot of cds cannot be used by unix-based
operating systems. I was wondering if there is a standard manner in which
companies make each specific disc 'proprietary' or is it just that unix
based systems cannot emulate effectively the ISO-9660 format? (Does that
make sense?) Vic
I guess I need to clarify another point. You can read ISO-9660 disks on a
UNIX book and you can access the data as you would a normal file but you
can't run DOS programs. My Atari ST and the IBM have the same type of
filesystem ("MS DOS LIKE"). I can move files back in forth between my
Atari and the IBM PC. I can read/write ascii, database, and other data
files without any problem. But I can't run DOS programs on my Atari. My
Atari uses a 68000 like an Apple MAC does and IBM uses the intel cpu 80286.
And the IBM can't run my Atari programs but they can share data because
they understand the same filesystem.
UNIX, Apple, Atari, IBM, etc can all understand ISO-9660 CD-ROMs, all
platforms can read the same data files. But you can only run IBM programs
on the IBM, Apple programs on an Apple, Atari programs on an Atari and UNIX
programs on a UNIX machine.
Propietary CD-ROMS can be very easy to do you can dump an Apple hard disk
to a CD-ROM so it is effectively an Apple hard disk. This can't be read on
other platforms very easily. You can have a file on the disk the the
program checks for and then makes a comparision with the hardware. Then if
this machine is not the same then it doesn't run the program. You can do
several things to make them proprietary very easily. The Sky is the limit
on that one.
UNIX systems now support the Rock Ridge format for CDROMs. What Rock Ridge
is … is an extension on top of ISO-9660. So you can still read a Rock
Ridge CD-ROM on any machine that can read ISO-9660. But only with a Rock
Ridge driver does one get all the benefits on UNIX on an ISO-9660 compliant
CD-ROM. This a perfect example of why ISO-9660 is such a great standard.
If you can put extensions on top of the standard and still have access to
the original standard (ISO-9660) you have designed a very good extension to
the standard.
Wow, there's a whole gaggle of info! thanks 🙂 it will take me a bit to
digest that! Vic
Albert –
Vic's answer that he can't run DOS applications under UNIX is incorrect.
Micro Design International supports CD-ROMs under AIX, DOS, Novell 386 and
UNIX (AT&T, Interactive and SCO). For UNIX and Novell 386, we create
something called a file set. A file set is a file which translates from
the CD-ROM file system (either ISO 9660 or High Sierra) to native operating
system. On feature that we have when using UNIX is the ability to create a
DOS file system. This file system can be mounted onto the UNIX environment
and access under DOS emulators, e.g. VP/ix. The only problem is if the
application on the CD-ROM tries to use the MSDOS Extensions or access a DOS
device driver. Since the CD-ROM isn't really running under DOS, but a DOS
emulator, then it will not function. For further information, please
contact us at 407-677-8333. -> Eric
Vic,
It is my understanding that on the level of an ASCII file dump (eg)
ISO 9660 disks are interchangeable between operating systems. OTOH, the
retirieval software is intrinsically OS dependent, and such things as index
files depend on the retrieval software. So a disk may be readable but
useless.
Multiplatform disks generally are that way by having multiple
executables on the same disk which can use the same index and data files.
Frank
The difficulty of promoting a system based on a non-mainstream OS is
two-fold; one based on technology, the other based in marketing.
As for technology, Albert Dayes and others have touched on the major
points. A 9660 disc may be readable by the CDROM drive, but the content of
the disc may not be usable by the system. Software is an obvious problem,
but there are also data formats that can cause problems, like grpahic
formats for example.
For publishers, the big problem is maketing. If they go to the trouble to
make their product compatible with your system, can they sell enough
product to make it worth it? Such conversions can be expensive, and
publishers seek to simplify their lives, not complicate them. CD-I is an
excellent example of a non-mainstream OS, and a closed delivery system,
which has proved to be a headache for many publishers because of low sales
returns for the considerable cost of conversion (are any of the CD-I
developers out there getting hot yet?)
Your biggest job will be showing publishers how they will benefit from
converting to your approach.