To: harv
From: Harv
Subject: Re: CD-ROMS: Everything You Need to Know About Producing Your Own
Date: Thu, 26 Dec 91 09:28:40 PST
Lines: 339
Aw, it's the holiday season, so rather than wait for a response, here's the
``Whole Ball of Wax'' regarding producing your own CD-ROMs. And though this
article already expired, there IS an alt.cd-rom newsgroup. "Local", in the
context of the following, means "Silicon Valley".
Enjoy!
Thad Floryan [ thad@btr.com (OR) {decwrl, mips, fernwood}!btr!thad ]
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Subject: Re: Producing a cd-rom: lessons learned
Date: Thu, 5 Dec 91 03:36:58 PST
Lines: 327
______
Here is a description of some of the things I learned while producing
my X11R5/GNU cd-rom. If you are thinking about making a cd, I hope you
find this information useful.
Equipment:
The most important thing you will need is a big magnetic disk. You
could do it with a 700 meg disk, but it is better to have twice that
amount so you can have two copies. That way you can make changes
on one copy, and be able to recover from the other if you screw
something up.
You will need a tape drive for backups, and for shipping your files
to the disk factory. I used an 8mm Exabyte. A 4mm DAT will also
work. All the disk factories I talked to will accept either 4mm or
8mm. Make sure you always make a backup before you make major
changes to your files.
It is possible to set up all your files under MS-DOS, MacOS,
but I wouldn't recommend it. Unix provides much better tools
for working with big filesystems. I used a sparcStation1 with
a 1.6GB Wren-8 disk drive. I had absolutely no problems with
either hardware or the system software.
It is good to have a couple different types of computers and CD
drives to test things on. I tested my stuff on a sparcStation-1
running SunOS with a Sony CD and a 386 running MS-DOS with a
Magnavox CD. These systems have different byte orders, different
OS's etc. I figured if things worked on both of them, it would
probably work on just about anything.
Handling data:
You need to get used to thinking in big numbers. My X11R5/GNU
CD-ROM contains over 35,000 files, and about 650 Megabytes of
data. It is almost impossible to do anything by hand. You
need to be able to automate things. The Unix `find' command
is very useful for traversing directories and performing
operations on files.
Choosing the format:
The first big decision you need to make is what format to use.
If your CD is targeted for just one platform, then you might
be able to use a special format. But if you want your CD to
be useful on different types of computers then you are stuck
with ISO-9660.
Besides portability, another big reason to use ISO-9660 is that
it is the only format supported by most of the factories that
press disks.
The ISO-9660 format places the following restrictions on your
filesystem:
The depth of directories is limited to eight levels. This wasn't
much of a problem for me.
Filenames are limited to eight single-case characters, a dot, and
a three character extension. Filenames cannot contain special
characters, (no hyphens, tildes, equals, or pluses). Only single
case letters, numbers, and underscores. (e.g. FOO_BAR.BAZ is ok).
Directory names cannot have the three digit extension, just
eight single-case characters. I didn't know about this restriction
until after I sent my tape to the disk factory. They called me
up and said the mastering software was choking on my directory
names. I had to make a new tape and send it off to them. This
problem delayed the project for about a week and a half.
If you are naming your own files, these restrictions are not too
onerous. But if you are trying to shoehorn a system like X11R5,
or Gnu where the files already have unix-type names, then it is more
of a problem. I wrote a program to scrunch all the filenames, and
then created a file in each directory that maps the new name onto
the original name. I then wrote a program to recursivley copy a
directory, (or, optionally, create a directory of symbolic links)
using the original names. If any of you ever need a similar program,
you are free to use mine without any restrictions. The source code
is included on the disk.
Disk manufacuturing:
I had my disks made by Discovery Systems (614) 761-2000.
I shopped around a little before deciding to go with Discovery.
They didn't have the absolute lowest prices, but they seemed to be
more computer oriented. Most other CD companies do mostly
audio CD's for the music industry, and cut a few CD-ROMS on the
side. But Discovery had some people that specialized in just
CD-ROMS. They were able to answer my technical questions with
out any problems.
The only problem I had with Discovery was that they promised
a five day turnaround, but they ended up taking longer.
Another company that seemed pretty good was Optical Media
International, (408) 376-3511, omi@applelink.apple.com. If
anybody has had CD's made by them, let me know how it went.
The factory can accept your data in several different forms. You
can send them a `one-off' (see below), or a tape. They will accept
8mm videotape, 4mm DAT, or 6250bpi 9-track tape. I used 8mm. The
tape can be in several formats: tar, ANSI format, or binary image.
I used tar because that was the easiest for me. I don't even know
what ANSI format is.
In order to send them a binary image you have to have your own
pre-mastering software. I looked into doing this. The Rockridge
System by Young Minds (714) 335-1350 seemed like the best, but at
$6995 it was way too expensive for me.
When you send your tape to the factory, it is a good idea to have
the following statistics available. It will enable them to layout
your files more efficiently:
Maximum number of files in any one directory
Total number of files
Total number of directories
Average file size
Largest file size
I sent two duplicate tapes. If there are any errors on the first
one, they can switch to the second. All of my tapes worked the
first time, but if there had been problems, the backup tape would
have saved lots of time.
One-off:
A one-off is a single copy of a CD. You can get one made from
a tar tape for about $300. You can then test it and make sure
everything is correct. You can skip this step if you want to
and just ship the tape directly to the disk factory.
I had a one-off made and I was glad I did because several things
were screwed up. I corrected all the problems, and then I sent
the tape to the disk factory without having a second one-off made.
I have heard that JVC is coming out with a cheap (less than
$10000) one-off system that will greatly reduce the cost of
having a one-off made. In fact, I might buy one of these myself.
Has anyone heard the latest rumors about when/if this will be
available?
I had my one-off made by `On-Site CD' (408) 867-0514. They are
a small company, just two guys working out of a spare bedroom.
But they are very quick. I drove down to Saratoga and dropped
off my tapes. They FedExed me the one-off two days later. There
were some problems with the one-off, mostly my fault, but some
of them were their fault. But they had just started doing business
a few weeks earlier and I was one of their first customers. I am
sure they have ironed out the problems. I would use them again.
Misc. problems:
There is a lot of buggy software in this world. Even if your own
software is reliable, the software used by the people that make
your disks may not be. Most software handles the common cases
properly but often does not handle unusual cases well. All of
these things caused me problems:
Filename that start with a dot (e.g. `.foo'). They get left
behind if someone does a `mv *.*'.
Zero length files. Some mastering programs will not create them.
Read only files on a tar tape. At least one tar program out there
will `creat' the file using read-only mode, and then try to open it
for writing. The write fails, and you end up with an empty file.
Make sure your files are mode 666 (or 777 if they are executables).
The mastering software will make all your files mode 555 when it puts
them onto the CD, regardless of what their original mode was.
Empty directories. Some mastering programs do not create the
directory until they put the first file into it. So empty
directories never get created.
All of these problems are pretty easily eliminated. Files
that start with a dot, zero length files and empty directories
are usually just cruft that should be eliminated anyway.
Disk Label:
The disk factory will send you the precise dimensions for the disk
label. You will need to create a film positive, emulsion side up.
You can use 2 colors in addition to the silver background. If you
use more than two colors you will have to pay extra. Make sure
your artwork doesn't bleed off the disk.
I don't know anything about this art stuff, so I hired a local
graphics artist to do it all for me. I just gave her a rough
sketch of what it should look like. She charged me $125, and
did an excellent job. She even drew a pretty good picture of
a gnu.
Cost:
Here is how I figure my expenses:
One-off:
$20.00 gasoline
$300.00 One off production
$30.00 Overnight Fedex
---------
$350.00 total for one-off
Mastering:
$1200.00 mastering cost
$875.00 pressing (500 x $1.75/disk)
$174.00 shipping for 500 disks 2nd day UPS
-------
$2149.00 total for mastering
Misc:
$125.00 Art work for disk label
$120.00 8mm tapes (backups, shipping files)
--------
$245.00
$350.00 one-off
$2149.00 mastering
$245.00 misc
--------
$2744.00 total
This total does not count the cost of equipment because I can
use it again, and it does not include the cost of my time
(probably about 100 hours or so).
This was only about half as much as I expected to spend. I had
about $5000 that I saved up for a down payment on a new pickup
truck. I figured I could get by with my old clunker for a little
while longer, but my girlfriend was really pissed off when I told
her I was spending the money to make a cd-rom. I was happy that it
turned out to cost less.
Time:
It took about two months from start to finish. Here is a rough
schedule of how long each phase took:
week 1 -- collect information
week 2 -- organize filesystem, munge filenames, create index files,
lots of testing, compiling, etc.
week 5 -- One-off made
week 6 -- fix problems, more testing
week 7 -- sent the first tape to the factory
week 8 -- fixed directory names, sent the second tape to the factory
week 9 -- disks are done
Administation:
A couple things that you should keep in mind when you are
ready to sell your disks:
Volume discounts: Lots of people will want to buy extra CD's to
pass on to their friends. You need to decide what your policy is
going to be. I decided to charge half price ($20) for all
additional CD's, as long as they are all shipped to the same
address. I think that is a pretty fair policy, and people seem
happy with it.
Sales tax: You have to charge sales tax for orders that are
shipped to the same state you live in. You need to get a tax
ID number from the state tax collectors office. I don't know
about other states, but in California the tax office goes by the
newspeak name of `The Board of Equalization'. Apparently there
is something in the U.S. Constitution that says you don't have to
pay sales tax if something is shipped from outside of your state.
International orders: I have been getting a lot of orders
from Europe/Asia/Australia. It costs a couple extra bucks
to ship overseas so you should charge a little more for shipping.
Canada and Mexico are cheaper, but not as cheap as domestic. I
guess I am doing my part to reduce the deficit. Now I don't have
to feel guilty when I buy a Japanese VCR.
Credit card orders: A lot of people will want to pay with
mastercard/visa. I went down to my bank and asked if I could
charge credit card orders to my personal checking account. After
the laughter subsided, the manager explained to me that I needed
to register a fictitious business name with the county clerk, set
up a business bank account, etc. I decided to do all this stuff,
but I would have been a lot better off if I had thought about it
a lot earlier.
I originally intended to just make this CD for the people here in
alt.cd-rom, but I have been getting a lot of orders from people
that heard about it elsewhere. You should be prepared to answer
a lot of naive questions. I have been getting inquiries from
people who have no idea what X11 or Gnu is.
Pricing:
CD-ROMs are a relatively low volume business, so I don't think it
is realistic to expect they will ever be as cheap as audio CDs.
But I can see no reason a cd-rom should cost any more than a good
technical book, about $40-$50. If you sell your disks for two or
three hundred bucks, then you will make more off each disk, but you
will sell a lot fewer of them.
If everyone charged high prices, then we would all be screwed
because no one would bother to buy cd-rom drives. It makes a lot
more sense to charge a reasonable price, and draw a lot more people
into the market. That way everyone benefits in the long run.
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Making a CD is not difficult. If you have been thinking about it, I
recommend that you go for it. I have already decided to make several
more.
If you have any questions about making a CD, or if you want one of
the X11R5/GNU CD's, feel free to contact me:
Bob Bruce
1547 Palos Verdes, Suite 260
Walnut Creek, CA 94596
(510) 947-5996
rab@sprite.Berkeley.EDU
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