Thanks to the Computer History Museum and some recent discussions in our community, the i2m PC-CD-i cards were mentioned again. One of our goals is to test these boards and do some experiments with them. Recently cdifan discussed the implementation of the i2M CD-i ROM in the new version of CD-i Emulator: We're still looking for the I2M cards. What were these based on? Even when we find one, it will be difficult to connect it and get it working (you'll need 'old equipment' with an ISA bus to start with; something we luckily have in the Home Computer Museum!). "At least the I2M cards did not contain a ROM as the software was downloaded from the PC. The drivers that are part of this can still be downloaded from ICDIA (so in fact there are some ROM files on ICDIA for years already!). In CD-i Emulator, the I2M card ROM is already halfway in booting.", cdifan explains.
| Image may be NSFW. Clik here to view.  |
| An original i2M CD-i card as how it was sent out bij International Interactive Media in 1996 |
Philips planned to create a software emulator in 1993 but it was not successfull. In 1993, Philips presented in its consumer catalog a CD-i set for use on your PC. It was a hardware emulation card connected via the ISA port to a Philips CD-ROM reader. It allowed you to playback CD-i titles on your PC, even with Digital Video support. In 1996 the i2m company released a CD-i emulation card for PC / Mac. This card, the i2m Mediaplayback Professional, is no less than a professional cd-i reader embedded on a PCI format card. This card was only sold in the professional market and its price, excluding software, was $ 1000. It was compatible with Windows 95/98 and it uses only resources of the host PC. Interesting detail was that these cards were also compatible to read from hard disks, so that you could load an image instead of a physical CD-i disc. (at the time, these type of images could be created via ShowBuilder (produced by an authoring CD-i system)
The card works by video overlay on your windows shell. Different resolutions are possible, depending on your PC setup (up to 1024x768) According to the manual of this i2M card you could also output the screen to an external television. The card would also allow video acquisition. The card has a set of connectors on the back: a Jack audio output to connect to an input of your sound card, a Mini-Din input to connect a CD-i device (Mouse, controller, gun, ... ), a BNC type socket used for the video output signal and a monitor (output signal) socket. Another interesting detail is that a CD-i mouse emulation mode is present in the software. The i2m card is placed in a PCI slot. When you restart the PC, Windows will detect the card. The I2m card does not require specific drivers to operate. Ignore the Windows request. Windows will ask for a specific driver however, which you can ignore. The i2m will appear as a "?" in the directory menu.
Like what was often needed in that time, you need to manually adapt the config.sys file to add a memory exclusion at the launch of emm386. The card is not compatible with Windows ME, XP or higher version. If you ever come across a i2M card, and you want to operate it, you'll need to find a working Windows 95 or Windows 98 machine. The application that allows you to use the i2m card is called "CD-i Playback". When it is launched, the card works in 3 modes:
1. Preview mode
This mode allows you to test non-burnt image files
2. The CDRTOS mode
This mode allows you to be in the operating system of the CD-i. It is possible to open an emulator window and directly type operating system commands (in OS-9))
3. CD-i mode
This is for us the most interesting now: it allows you to play CD-i discs. After inserting a CD, the title of the disc appears in the menu bar. By pressing Ctrl+M you can take control of the CD-i cursor with your mouse. and you can start playing CD-i on your PC!
| Image may be NSFW. Clik here to view.  |
| This i2M CD-i card is currently in the Computer History Museum |
cdifan, the author of CD-i Emulator, also implemented some pieces of the i2M into CD-i Emulator. cdifan:"I did some work on emulating the I2M Media Playback CD-i board for the PC (in a sense another completely different player generation). This board uses a Motorola 68341 so-called "CD-i Engine" processor chip, which is a CPU32 processor core with some on-chip peripherals (a DMA controller, two different serial interfaces, a timer, etc), a VDSC video chip and a completely undocumented "host interface" to the PC bus. So far the board does not appear to have a separate CD/Audio interface, but it does have a VMPEG chip. I had already implemented CPU32 emulation and partial emulation of its on-chip peripherals, but this needed to be extended a bit more. The main "problem" here appeared to be that these peripherals appear to ignore address bit 23.
I also had to reverse engineer the host interface, which amounted to some disassembly and tracing. In the process I also figured out that I had built a bad ROM image (the host software generates these on the fly from "ROM fragment" files and I had mis-interpreted the script file that tells it how to do this). I used the CD-i Playback 2.2.1 files for this. The I2M board now successfully boots OS9, including displaying some tracing messages (it turns out that it can do this either via the host interface or via the serial interface, which was reason for lot's of head scratching until the "aha!" moment). The video display gets initialized (some kind of "blue" screen) and the then board "hangs" inside a watchdog process, presumably waiting on some signal from the host telling it what to do (it's not a crash but appears to be waiting for some host interrupt)."
[Thanks, Planet Numerique, cdibits.blogspot.com, cdifan, Vogon, Computer History Museum]