Conference noted::ibmpc-95

    The dual DMA/IRQ sound cards are referred to as "duplex", which 
    basically allows you to talk and listen at the same time in video
    conferencing apps.  Other than that, I fail to see the attraction.
    The old Pro Audio Spectrum can also be set up to do this, as well
    as the ESS1888 as used in Celebris GL.
    K

Actually, I don't think the dual DMA has much to do with duplexing.  I
think it has a lot to do with using a 16 bit DMA if available.

I've often tricked Sound Blasters into using a single 8 bit DMA (back in
the bad old days when my old 486 motherboard couldn't handle 16 bit DMA
without crashing).  I found no differences:  MIDI worked (since DMA is only
really used for D-A output), synthesis worked, and most importantly, 16 bit
D-A continued to work.

    .2 has it right - the two DMA channels preceded (by at least a couple
    of years) any "full-duplex" buzz. 
    
    The additional 16-bit DMA is found on any sound card sold in the last
    few years; the 8-bit channel is the "fall-back" for motherboards that
    didn't get the 16-bit DMA implementation right (there were plenty of
    those around - trust me) and/or for app's (read: games) that didn't know
    how to use a 16-bit DMA channel. 
    
    CL's DOS/Win311/WfWg311 drivers can be set to use only the 8-bit
    channel (I don't know about Win95). I wouldn't think there'd be an
    impact to MIDI if only the 8-bit channel is used (in fact I don't know
    that MIDI even uses DMA). There's so little data moved under MIDI
    (compared to 44khz stereo Wave stuff) I'd be a bit surprised if MIDI
    used the DMA engine for anything...
    
    /dave

    
    So, if I want a good sound card reasonably priced I should just stick
    with a 16-bit SB compatible board? I was thinking of going with the 
    SB32 or AWE32. What should I do? I use it mostly for gaming (sound
    wise)....Cost is a factor also, and must be SB compatible. I can get a
    clone for $45 for a 16 bit card...
    
    

The MIDI port it programmed I/O only -- no DMA is involved.  In fact, if you 
only do output from the computer to the MIDI port, you'll never use the IRQ 
assigned to the MIDI port, either.  Interrupts are only used for input (if 
then).  A MIDI port is just a UART, very similiar to the COM port UARTs.

    you can get a 16 bit SB compatible with 3D sound for $30-$35 at any
    local show. Probbaly cheaper on the web mailorder, but add shipping.
    for games...why spend a lot of money?? 16bit sounds great :)

    re: .4
    
    The "32" in the SB32 and AWE32 refers to the number of "voices" that
    those cards can play simultaneously. It doesn't refer to either DMA or
    data width. In fact they're both 16-bit ISA cards. And either of them
    will work as advertised.
    
    As for the suggestion of even cheaper clone cards: I don't know what
    the current state of the CL clone biz is. I've always stuck to the
    genuine CL products as they've historically been the only known
    quantity ("Soundblaster Compatible" was always The Big Lie - at least
    in the past). Perhaps with CL's Vibra16 chip being used in many (most?)
    clone cards, that's less of an issue today...
    
    /dave

    
    rep .7
    
    I agree with .7, I only buy Creative Labs Sound Cards, nothing else
    is 100% C.L. compatible.  
    
    If this is for a game machine, some game will not like the Clone S.B.
    
    I currently have a Media Vision, Acer, and a Media Spectrum, all
    clones, that have some sort of incompatibility.
    
    Pepsi isn't Coke!
    
    For $65 - $70 you can get a C.L. Soundblaster 16, don't skimp!
    
    /art

    In an earlier comment it sounded like the noter was switching to a
    cheap clone just because DMA wasn't a factor in processing MIDI.
    
    Well, thats okay as far as it goes, but that implies that you'll be
    piping the MIDI controller commands out to an external MIDI
    synthesizer.  If true, then a cheap sound card will be fine, because
    you're essentially using the sound card as an IO port, like a COMM or
    LPT.
    
    However, if you plan on plugging speakers (or an amp and speakers) into
    the sound card at all, it makes BIG difference what type card you have.
    Cheap, non-wavetable cards do FM synthesis to simulate the musical
    instruments the MIDI program wants to "play".  The synthesis is poor
    (that is, the instrument sounds it produces sound fake), and the
    instruments simulated are few in number (just about everything ends up
    sounding like an organ or a drum).
    
    If you are SURE you'll never plug in a speaker or headphone to the
    card, and plan to pipe everything into an external synthesizer ($$$),
    then go for it.  Otherwise, I'd *at least* get a card that will accept
    a wave table daughter card.  These cards use sampling of actual
    instruments to add realism, and typically have anywhere from 32 to 256
    distinct instruments to choose from.
    
    For example, just by plugging in the wave table card, the sound for
    XCOM:TFTD was dramatically improved.  And that software doesn't exactly
    fall into the multi-media category at all.
    
    jeb
    

    Actually, my reason for writing the base note is that I've been playing
    using multiple sound cards in one PC to expand the number of wavetable
    voices and midi ports available for music composition.  So, assume the
    first card is an SB 32 set to all defaults to cover most basic system
    uses.  Then a second card (and then N cards?) for the purpose of
    wavetable voices and midi port use as driven by a composing program
    such as Cakewalk Pro. 
    
    Genuine SB cards only use 1 IRQ because the MPU 401 is an emulation. Most 
    clones use 2 IRQs, one for the SB emulation and one for the MPU401 midi 
    output. If earlier replies are correct in saying that configuring the
    SB 32 for only one DMA will not adversly affect internal midi wavetable 
    voices and external midi port use, then multiple SB 32s would seem to
    be the most likely way to conserve enough system resources to enable
    configuration and use of multiple sound cards for compositions that
    require a lot of voices. A much more expensive alternative would be a
    stack of external midi modules, but I only have one or two of those at
    this point. The multiple midi ports would make using multiple midi
    controllers easier as well........................Jon......... 

    
    re: last few
    
    I am going to get a CL Vibra16 from my buddy along with a 12x CDRom
    drive he has (told him to hold one for me!) at a decent price for the
    pair. I will only have speakers hooked up to it and may add a wavetable
    later, but can't see a reason to do so now.
    
    

    I have just found another simply solution for multiple MIDI busses
    are the MidiMAN and Music Quest PC parallel-port-to-MIDI (or 2 or 4
    MIDI) ports.  These range in price from ~$70-$200, with upper end
    supporting SMPTE-to-MIDI (time-code) and vice-versa translation.
    
    The parallel port is the only solution currently available for laptop
    PCs, if you want portable MIDI.  I just ordered a Music Quest 
    2 PORT /SE (distributed thru OPCODE: see http://www.opcode.com/),
    which provides 2 MIDI in and 2 MIDI out, SMPTE translation, and
    parallel port buffering so that software isn't waiting to Tx/Rx 
    each byte.  It appears that both Music Quest and MIDIman are 
    very popular for midi-cards in general.  Mark of the Unicorn (MOTU)
    also offers parallel converters, with a unit available in Nashua's
    E.U. Wurlitzer store (next to Staples & CompUSA) for $200 (2-in, 2 out, 
    parallel, SMPTE).
    
    	Bob Brassard