If one runs modified (a little utility that drives the AC97 codec is run and it doesn't check the hardware code) Emu APS drivers on an SBLive one has: "8 ms latency, 4 seperate analog outputs, 2 digital outputs, new effects, SF2.1, Midi controllable hardware" Only one analog output channel can be used as analog output is done through an AC97 CODEC (which is what gives the SB it's poor quality) however you can use multiple digital I\Os. Go to http://come.to/SBLive/ for more info. Tom. -----Original Message----- From: Kyrre Aalerud [mailto:kreature@C2I.NET] Sent: Friday, February 23, 2001 9:53 AM To: PICLIST@MITVMA.MIT.EDU Subject: [EE]: INfo on the SP/DIF system and some on the Soundblaster Live / 5.1 series soundcards from creative... OK, after my post about SP/DIF I got afew mails where I was asked to share what I know about the SP/DIF and Creative systems. I will now spill my guts :-) Most of my knowledge on the SP/DIF system is actually based on the following links, so I will NOT take credit for this. http://www.epanorama.net/documents/audio/spdif.html Very good info on the SP/DIF codec and AES/EBU. There are altso numerous converter circuits there. I am working on a modification of some of theese so that I can do TTL or 0.5Vptp signals on the same input and convert to TTL and Optical... This page has oltso very good info on the format on the SP/DIF data. Here you can learn how to manipulate the stream to conform with or break copyright if you read closely. All specs are there. It altso states the possibility for multichannel beyond stereo. (Wich is why I am thinking about a four-channel version/muxer...) http://www.cl.cam.ac.uk/Research/SRG/HAN/docs/sp-dif.txt More info on the SP/DIF. All by DJ Greaves. More of a history lesson :-) http://members.tripod.com/~Psych/md-cdrom.html Even more info. This time with more circuits... Using a CD-ROMs SP/Dif etc... CD-rom tom minidisc is altso covered :-) In addition to this I have found some stuff on my own about the SBs. I have altso talked to Creative Tech personell and designers, but they are very sparse with info. What I do know: The Creative SB Live 1024 has four digital output channels onboard. Theese are situated in a yellow 4 channel mini-jack on the back of the card. The reason for the four channels is that there are ground reference and power in this plug. This is altso why your computer may hang if you connect a plug into this socket while running. You actually short some of the power in the computer before the card realizes what is happening and disables it. This power makes it possible for the "Digital Output Module" to function and convert the two digital stereo channels to Toslink optical. The bad thing is that theese two channels can't be used by a normal decoder as fourpoint sorround since they are two seperate stereo signals. Unless you have some Digital desktop theatre wich is designet for this specifig purpose. Recieving two digital streams one for the front and one for the back speakers, and then amplifying and outputting to speakers. Other recievers/amplifiers want this signal in any of the following: (All on one digital transmission channel) 1) Mono digital 2) Stereo Digital in PCM/RAW 3) Multichannel (4point) can possibly be PCM/RAW 4) AC3 multi/single channel streams 5) DTS or similar streams... All on one channel... There may be others, but who can know everything ? The Soundblaster Live 5.1 is different. They have removed the power on the yellow connector. Now the card wont hang your system if you connect something while computer is runnjng. But, alas now you can't use the Digital Output Module either! The new card has an extra digital stereo output. This is for the center and sub channels. All SB digital outputs are TTL level, so interfacing a PIC would be no challenge. Altso most recievers accept this TTL level SP/DIF with no mucking about :-) Altso: There are ways to enable extra line inputs and SP/DIF digital inputs and outputs on both Live cards as well as the SB128. This is seamingly done by interfacing/connecting systems and jumpers/resistors to the internal pin header on the boards. The drivers should normally detect theese "enhancements" at bootup. The last thing I will add it that NO, there is NO way of getting the soundcard to output a multichannel (more that 2) digital stream to a reciever, unless you are playing some AC3 or multichannel source with special software. (Like a AC3 output compatible software DVD-player) Creative was simply to cheap to include hardware that would do this compression/encoding on the fly. You can however do a software recompression of up to six channels using comercial software and then outputting on the primary/front speakers digital output. This would be like playing a DVD or thelike. What I am trying to find out is if there is a way to let a (perhaps top-line) PIC do some multiplexing/coding to atleast get four channels into a PCM or similar stream... Any extra info or reports on errors are greatly apprechiated! (Whew! that was alot of typing!) KreAture -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics