(*) Beside the midi-in interrupt this chip offers a midi-out interrupt (no polling).
(1) We may program DSP FX8010 in order to apply hardware effects in future...
(2) Digital mixer will only render one analog input (MIC/CD/LINE/AUX) while recording it.
(3) CD analog input is missing. Connect your analog CD cable to AUX analog input.
(4) AUX analog input is physically connected to CD input of analog mixer (use CD volume).
(5) Recording of CD and AUX analog inputs did not work on this card (but CD playback works).
(6) This card DOES NOT HAVE output low pass filters (add them yourself or you will get HF noise!).
(No output filters means you can create a 24Khz square waveform, but who needs that ?)
About sound :
Minilgos will use 16 bits stereo full duplex 48Khz sound (DMA playback and recording at same time), external MIDI devices support (playback and recording) and mixer management (master volume, specific volumes and source selection MIC/CD/LINE/AUX, recording gain and microphone boost switch). SPDIF (digital input/output), 24 bits format, 32 bits format, or 4.0/4.1/5.1/7.1 sound configuration are not used at the moment, but may be used in future...
In order to verify that you have the correct sound card or mother board integrated sound chip, just check for the line "Multimedia Device" at boot time and write down the Vendor_ID and Device_ID (mother boards integrated interfaces are considered as PCI devices). Another method is to find entry "PCI\VEN_nnnn&DEV_nnnn..." related to your audio peripheral, in tool "System information", in "components->multimedia" category (with your local hard disk operating system : startup->programs->accessories->system tools). If (Vendor_ID,Device_ID) matches the numbers given in the above list, then you have the correct sound hardware for Minilgos. If you plan to purchase a low cost assembled PC, check with your favorite assembler if he can find a mother board with a supported sound chip integrated in it. In last resort, purchase a supported sound card at a price that should not exceed 15€ for stereo and 40€ for dolby 5.1.
For standard music, Minilgos rather likes taking you to the MIDI universe since it gives the best sound quality and slowly invites you to create music yourself. It's not as expensive as you may expect... MIDI is a protocol allowing to record/render the way musicians strike their instrument keys over time. ".MID" files, named "standard midi files", can store simultaneous notes from many instruments (with lyrics display eventually). Physically you will need a MIDI cable (15€, a Joystick port/Midi adapter) that will be plugged to your joystick port (available on supported sound card or mother board described above; laptops may require additional docking accessories if joystick port is not visible) and will give you a MIDI-out & a MIDI-in connector. In order to record your own music, a MIDI piano keyboard (60€) can be connected to MIDI-in connector. To render music, a MIDI expander (a box ready to render an incredible amount of instruments notes with very high quality, for example a Roland MT-32 from ebay -50€- or a Roland MT-90s -300€-) can be connected to MIDI-out connector. Remember that Minilgos main goal is to bring new knowledge and training to its user, especially very young user. Of course Music lessons will be offered in Web pages, and training will require a MIDI keyboard... (do not forget that children can train themselves silently with a MIDI keyboard if they use headphones)
There are several reasons for using a MIDI expander for music rendering :
- If you let computer play notes with a software wave table you will notice around 500ms delay between your piano key hit and the note rendering (believe me it's VERY disturbing) because playback is DMA driven (data is sent from memory to sound chip without any control from processor because it has no acceptable way to do it itself at the exact needed time, at so high frequency) with a circular buffer that receives new data only twice a cycle which lasts around 1s.
- If you let computer play notes with a frequency modulation generator you won't get any delay but you will lose all sound details and you may not even recognize the instrument.
- An expander can mix more notes simultaneously than a cheap sound chip, without quality loss or delay. Also, high quality instruments waveforms are copyrighted and so can't be used in a free software. That's why expanders are not cheap.
- If you plan to create your own final music file including a singer voice, you will probably get higher quality by recording expander output while singer microphone is connected to expander microphone input (MT-90s has one).
Minilgos phone over internet feature requires a microphone connected to sound card or mother board microphone input. It's quite possible to create an adapter to connect a standard phone. Since it requires high voltage (24 volts minimum), adapter will have its own power supply to maintain a 25 mA current loop inside phone. Warn us if you ever find this kind of adapter or electronic kit on the market (Phone/2.5mm Jack in & out), so we can add a link here for interested customers.
To be honest, you may have to consider Minilgos "Phone" over internet feature as a Minilgos to Minilgos only "Talky Walky" over internet feature because this feature is actually based on global internet exchanges, thus free whatever is the location of the Minilgos user you call. But since you can't predict global internet overloads, data may take a long time to reach destination, creating a strong delay in your chat. You can see now a lots of advertising from DSL ISPs giving a true phone over internet service but it's limited to national calls only and not allowed toward mobile phones, because you pay when you call a mobile phone and when you call someone outside of ISP territory (where their network can call other phone locally). Since it's an internal service they can manage to give you a short delay in internet packets exchange through a reserved internal network under their control (extreme low overload risk). No special effort will be made to allow a Minilgos user to call a non-Minilgos user, since Minilgos is free and anyone can create cd with a not so hard to get sound hardware requirement. On the other hand, if destination is close you will actually enjoy a virtual phone or intercom in your house or office, easy to access from Minilgos phone book screen. Call is done through target IP address reading via HTTP or an automatic e-mail, then a direct TCP/IP connection without any intermediary server (directory). Usually you schedule/invite your call through e-mail or you do one single classic ring call, then you wait/initiate call in Minilgos phone book screen.
Minilgos won't support MPEG-Layer-3 related technologies, i.e for example sound/music format MP3, because of royalties demanded by some MPEG group members (www.mp3licensing.com). Since the main idea is quite simple (switch to frequencies, remove sound/graphics you can't hear/view, then compress), another format has been quickly created, with this time warranty that no one will ask -long time after- for royalties : Ogg Vorbis format. Minilgos will use this format. If you want to listen to .OGG musics or watch .OGM movies with your local hard disk operating system, you can download "The core media player" from www.corecoded.com. Note that you will probably obtain a better quality if you download or record music again directly in .OGG format rather than converting a .MP3 file into a .OGG file.