Searching for Sherlock Holmes - Consulting Detective CDTV

[Toni Wilen]

Originally Posted by thor

Did you try running CDTV\CDTVTOOLS-11\CDXL\XL.C example?

I have this exact same question. Perhaps single sector read is not supported (single sector XL animation is not very useful after all )

[musashi5150]

Sorry, yes I did try that code. It read 0 bytes repeatedly from sector 19587 (start of 1st videotrack)... which I guess means it wasn't working.

[Toni Wilen]

I did some tests with the broken image.

Freezing at ICOM screen is CDTV emulation bug (Play CD audio, LSN mode, command's parameters are start sector and length, not start and end sector..) Fixed it and main menu works.

Some READXL start sectors after selecting main menu item:

IORequest length=1

IORequest start sectors (Offset):

Holmes' Introduction: 81344
The Mummy's Curse: 19737
The Mystified Murderess: 86209
The Tin Soldier: 168037

CDXL-structure: (address in my test was 0351bc)

0351b4 (no more nodes, points to zero)
0351bc
033fce (data)
000920 (length)
0351d4 (donefunc), points to RTS
000000 (actual, 000920 after call returns)

It retries this command 10 times and corrupts copperlist and graphics.

[musashi5150]

Thanks for those offsets Toni - I'll give those a try when I get home. My question is though what is in in "empty" sectors at the beginning of the videotracks?

Eg. If 1st videotrack (Mummy Curse) starts at 19587, they why does video start at 19737 ? Probably isn't important, but I'm curious. Could it be a "lead in" of some type...

[Toni Wilen]

I know you said Isobuster (2.1 appears to be latest) didn't work but did you try extracting in raw (2352 byte/sector) mode? (both complete CD and track by track)

Perhaps most programs confuse sector sizes and try to access it in 2048-byte sector mode?

Track appears to be rarely used mode 2 form 2 which means 2336 user bytes without error correction, CDTV also sets drive to 2336 byte mode before it starts READXL transfer and puts back to 2048 byte mode before next normal data read.

Note that CDTV emulation does not yet support 2336 byte accesses. I think I have it nearly finished but I need better image for testing.. only some random sectors in track 2 can be read in "XAForm2"-mode, 90% of sectors only return errors. (interestingly reading in 2048-byte mode returns no errors and 0 bytes of data)

[thor]

So if those tracks are standard mode 2 form 2, maybe the (random data?) in those sectors (i.e 19587-19736) cause the problems with reading the CD and it works ingame as it doesn't attempt to read those sectors?

Originally Posted by Toni Wilen

I think I have it nearly finished but I need better image for testing..

If you're interested and it helps, musashi5150 can send the CD to you for examination when he has finished and then you could send it back to me.

[musashi5150]

I just downloaded and tried IsoBuster RAW on the whole CD and individual tracks and it didn't work.

I also tried dumpxlsector on all the new offsets and that didn't work either.

So then I modded dumpxlsector to load various amount of data (CDXL.Length) and I also changed around the CDXL transfer list a little, but still no luck

Toni, can you make any changes to dumpxlsector.c program (XL.LHA in the Zone) that you think might be necessary... I'm all out of ideas now.

[viddi]

Oh no

So much work...

[musashi5150]

Don't lose faith viddi... I have every faith in Toni the Jedi Master

[Toni Wilen]

I missed something very important in my debug log..

Game sends (undocumented) CDTV_OPTIONS IO-command (38) before starting CDXL video.

CMD=38 DATA=0 LEN=2336 (sector size!, 2048 when XL sequence ends) OFFSET=1 I am sure this is the missing piece

cdtv.device changes this to CD hardware command 84.00.09.20.00.00.00 (I thought cdtv.device created this internally but it was the game that did it..)

So if those tracks are standard mode 2 form 2, maybe the (random data?) in those sectors (i.e 19587-19736) cause the problems with reading the CD and it works ingame as it doesn't attempt to read those sectors?

I still think it must be mastering error that was not noticed, perhaps in never tested mixed mode with mode 1 + mode 2 form 2 + audio tracks handling. (something like it confused them with audio tracks and put empty gaps between them or something..)

Do you see any visible rings between tracks or similar?

[thor]

Originally Posted by Toni Wilen

Game sends (undocumented) CDTV_OPTIONS IO-command (38) before starting CDXL video.

CMD=38 DATA=0 LEN=2336 (sector size!, 2048 when XL sequence ends) OFFSET=1 I am sure this is the missing piece

cdtv.device changes this to CD hardware command 84.00.09.20.00.00.00 (I thought cdtv.device created this internally but it was the game that did it..)

CDTV_OPTIONS seems to support two values for io_Offset as defined in the CDTV.h header:

/*
** CDTV_OPTIONS Command values (io_Offset)
*/
#define CDTV_OPTIONS_BLOCK_SIZE 1    /* CD-ROM block size    */
#define CDTV_OPTIONS_ERROR_TYPE    2    /* Error recovery type    */

[musashi5150]

Aha! That sounds like a missing piece indeed ... I'll try that tonight. And we are saying that CDXL sectors are 2336 instead of 2048 for dumping - correct ?

From memory I don't recall any rings on the CD but I'll confirm when I'm home again. Great work Toni.

[Toni Wilen]

Originally Posted by musashi5150

And we are saying that CDXL sectors are 2336 instead of 2048 for dumping - correct ?

Yes, 2336 bytes/sector in this case. (creating new fixed image may not be trivial, single 2048 byte mode1 track + some mode2 form2 tracks and finally some audio tracks.. Does any CD burning software even support that kind of combinations?)

btw, don't mix sector format and data format:

CD_READXL can read any kind of sectors, it does not need to be "XL" formatted video. Sector size can be either 2048 or 2336 (perhaps 2352 is also possible but I don't know if the hardware supports it).

Regular READ can only read 2048 byte sectors. (but can also read XL 2048 byte sectors if streaming is not needed)

[musashi5150]

One more question... are the sector numbers still valid ? According to the burning packages I've tested and the CDTV TOC of the disc, I have the sector offsets for the start of the various tracks.

Are these sector numbers still valid even though the sector size changes from 2048 to 2336?

EDIT: And as for burning... we will have to see. I can write a nice cuesheet and then I'll try various software. If this works of course

[musashi5150]

Whoops.. forget the question about sectors. The only difference between 2336 and 2048 is that the error correction fields aren't used.. thus making the user data area bigger Duh.

[Toni Wilen]

I'll release beta winuae later today with 2336 sector support (=read full 2352 byte sector and convert it to 2336 byte version by removing 16 bytes from the beginning) It should work with original CD, at least in theory...

[musashi5150]

I'll try that as well

[Toni Wilen]

cdtv-winuae-beta

run it with -log and -scsilog parameters in windowed mode.

-trackmode <x> is used to change different reading modes (0 to 4). Try without trackmode first. 1 or 2 "should" work but IOCTL_CDROM_RAW_READ documentation is really bad and confusing.. (and I don't have any test CDs..)

[musashi5150]

I've PMd you about your Beta, Toni.

Looking at the CD it does have a ring. The first centimeter or so on the outside is different to the rest of the disc.

I will now try to mod my program to see if your 'missing piece' helps - fingers crossed

[DamienD]

musashi5150, thor and Toni Wilen... Nice to see you all combining your skills to solve a problem

You are all doing an excellent job trying to conquer this

Best of luck guys, we have faith