Specifications
CD-i FAQ 2000 Edition Revised February 21, 2001
Latest version and more CD-i info: http://www.icdia.org
45
Refer to Philips professional and authoring CD-i players in the Complete CD-i Players Overview
at www.icdia.org for a comparison.
7.4 What is a CD-i Emulator?
A CD-i Emulator is a piece of hardware that contains a large harddisk and control circuitry to
provide a stream of audio, video and program data to a CD-i authoring player in exactly the same
way as if it was being read from a CD. The Emulator takes care of interleaving the data, creating
the sector format and contiuning the feed of data according to the specification as laid down in
the Green Book. When a CD-i Disc Image is being created, it can be read by the Emulator and
played trough the CD-i authoring player for testing purposes. You need either to do this, or make
a one-off on CD-R for testing, because you can't test CD-i's realtime behaviour at programming
level (the audio, video and program data is not interleaved yet at that time). Since CD-R was just
beginning to appear when this CD-i authoring hardware became available (early 90s), and a CD-
R disc costed around US$ 50 a piece, a CD-i Emulator was a very economical solution for
studios.
Two versions of the Emulator were being sold by OptImage. Both of them contained at least a 1.2
GB harddisk (enough to keep all data of a disc in its original form and the required space for a full
CD-i Disc Image). The Emulator was based on the same version of OS-9 that is used in CD-i
players, and they contained 2 MB of memory. The first model was generally refered to as E1
(probably Edition 1), it runs on a 20 MHz 68020 and contained a floppy disk drive which needed a
suitable floppydisk to boot the system up, and a lot of confusing connector types at the back. The
E2, which was released some years later and runs on a 24 MHz 68340, lacked the floppy disk
drive since all required software was build in ROM, and it had a more convenient way of
connecting to the CD-i authoring player.
Both versions of the Emulator can also be used for the emulation of other CD-i compatible disc
formats like Photo-CD and Video-CD. Some Video-CD studios are known to use a CD-i
development player and and Emulator in their quality checks.
7.5 Do I need special hardware to make a CD-i title?
In therory: no. If you have the approriate CD-i authoring software that runs on a PC (like the
Presentation CD package, or Philips' ShowBuilder package for Windows, both available from the
PC/Windows downloads page at www.icdia.org), you can produce a CD-i title entirely without
any additional hardware besides your PC. Bear in mind however, that the results from these
authoring tools are very linear and without much interactive features. Even if you had a tool that
provides you a way of creating a more complex CD-i title on a PC, you still wouldn't be able to
test the behaviour of it on a CD-i player, since CD-i cannot be "emulated" in any way on a PC. A
one-off CD-R would need to be pressed at the various development stages, which would be very
inconvenient.
All CD-i titles that you see around are created with either low level authoring tools on a PC,
Macinthosh, Sun or OS-9 system which was connected to a CD-i development player and
emulator, or entirely on a CD-i development player using a high-level authoring tool like
MediaMogul. Refer to: 7.7 What CD-i authoring tools were available? for more information about
the available tools.
7.6 What is OptImage?
OptImage was the name of the largest company that selled CD-i authoring solutions in the form of
hardware and software products and development support. It was set up by Philips, Microware
(the creator of the OS-9 operating system used in CD-i) and Sun Microsystems (creator of high-
end workstations that were used in CD-i development a lot) in the late 80s. They developed
various tools, and from the early 90s Philips and Microware became the owners of the company.