CD-i update

Over the last few days I did some CD-i website updates.

On the CD-i Emulator website http://www.cdiemu.org I added lots of hardware pictures taken in August of last year. These include an extensive series about my (then) new 180/181/182 authoring player set and some overview pictures of the FW380i player and my E1/E2 emulator hardware. I have many more pictures of the internals of those emulators but these still need adding. I also added some more serial number information, especially from the DV cartridges. Some of the pictures of those appear to be mixed up a bit and will need sorting out.

I also started creating a Books section to list all my hardcopy documentation, as part of an effort to scan some of it to create digital versions where needed, but that is not yet online.

The end goal here is to get everything that could possibly be needed by a CD-i title developer online in a single place.  This effort started in July 2017 when I took over editorial maintenance of the ICDIA website at http://www.icdia.co.uk from Devin. We had decided that the CD-i Emulator site was not the right place to put general CD-i documentation and the ICDIA site seemed a much better fit.  And Devin was looking for a new ICDIA editor anyway, so...

As my first action on the ICDIA website I added the CD-i Full Functional Specification (Green Book). It had already been online for years but was not very easy to find.  Next followed some more Microware OS-9 documentation (in particular the Allen-Bradley set) that was also already online, and today many service manuals (repair instructions including board and circuit diagrams) were added.

A start has also been made with adding authoring documentation, but much more of that still needs to be added. My hard disk contains a number of raw scans from last year that still need to be processed and put online. In particular, this includes the CD-I System Libraries Technical Reference Manual that contains C bindings for all the CD-i specific CD-RTOS functions described in the Green book; this information is an absolute must to have for any serious developer.

Devin has been sitting on a complete set of CD-i Technical Notes for developers for a long time; this needs to be scanned and put online also (so far he has only done a very limited subset of it). These notes document many intricacies of the CD-i system and can be very insightful for title developers

It has now been a very long time since I put anything on this blog, but this does not mean that CD-i related software development has stopped. However, it has slowed down considerably. Below is a very short (and unordered) list of my CD-i development related activities in the 7 years since I last posted here; most of these I will probably expand on in the future.
 
- handling of CD-i Emulator beta time limit expiry
- emulation and deconstruction of The 7th Guest for the 20th anniversary edition
- leveraging CD-i Emulator code for a homebrew project
- investigation of possible Android and SDL ports of CD-i Emulator
- restructure of CD-i Emulator video decoding for flexibility and performance
- investigation of current status of Microware CD-i build tools
- investigation of existing OS-9 ports of the GNU C/C++ compiler
- investigation of restructuring CD-i Emulator MPEG decoding to fix buffering issues
- substantive efforts at ROMless emulation for CD-i Emulator (promising but not finished)
- reaching out in an attempt to collect more CD-i player ROMs

Regarding the last item, from the Philips consumer player line I’m still missing ROMs from the CDI 210/00, CDI 210/60, CDI 220/80, CDI 380/00 and CDI 740/20 players. If anybody has one of these players, please contact me.

I’m also interested in more exotic players like the Philips CDI 602, CDI 604, CDI 610, CDI 611 and of course a number of non-Philips players, in particular the Bang & Olufsen BeoCenter AV5. For some of these there are possible acquisition routes, but it requires bugging people about them and that can only be done some much.

Last year I also acquired a Kyocera Pro 1000S player that so far hasn’t given up its ROM contents (the player is incredibly densely packed internally, but there appears to be a serial extension port that could be usable), and I’m also still looking for the SONY IVO player ROMs. If nothing else works, it should be possible to play out the ROM contents of these players as audio.

There are also many future projects that I’m still interested in; a new one as of today is getting the built-in service tests of the Mini-MMC and Mono-I players working as documented in the service manuals. These tests need a special Service PCB connected to the serial port that has only three buttons (TEST, YES, NO) and an 8-position 7-segment LED display. Part of these tests is probably run by the SLAVE processor, but ROM contents for this processor have recently become available from the MESS dumping efforts so there appears to be a possible route. It would require implementing 6805 processor emulation but that shouldn’t be that hard, this is a relatively simple and well-documented 8-bit microprocessor.

Having made a promising start with ROMless emulation (in particular, mostly working C++ versions of the video and pointer device drivers and a good setup to start developing C++ versions of the kernel and remaining drivers and file managers), it appears worthwhile to pursue this path as well. It would  make the (apparently) holy grail of CD-i emulation a possibility (no need for copyrighted player ROM contents, just the disc images) and would open up a path to re-releasing CD-i titles on other platforms without ROM rights issues (several title rights-owners have contacted me about this in the last few years). If done right (which I’m trying), it would even allow a rebuild of the CD-RTOS software from the C++ versions by compiling them with an OS-9 C++ compiler (GNU C++ comes to mind). Of course, this would not be the “authentic” CD-i experience but it would allow playing of supported titles (eventually, this should be most of them).

It would also be interesting to make more progress towards an SDL port of CD-i Emulator. The main structural barrier to this has already been removed; the CD-i video emulation used to be hardcoded for producing 24-bit Windows-compatible RGB format. This has now been replaced by more generic pixel-format-parameterized pixel generation code that can efficiently produce any RGB format fitting in 32 bits, as required by SDL; in the process also achieving some decoding performance improvement (in particular, more optimized region processing). A faceless SDL emulation (no GUI) should now not be very hard anymore; at some point an SDL-based GUI or perhaps a native Android / iOS / MacOS GUI could then be added.

So there’s still lots of work to do…