Conference napalm::commusic_v1

1346.0. "Qbus to MIDI, How (and Why?)" by ELESYS::JASNIEWSKI (I know from just bein' around) Mon May 02 1988 18:29

    
    	I recall waaaay back in these notes there was some interest
    in a Q_bus to MIDI converter. Since, I imagine, anyone who was
    interested has picked up a mac, pc, amiga, commodore or whatever
    it takes to be able to compose, store and drive MIDI instruments.
    That is, converters are available for S100, PC, ...whatever busses
    to MIDI. The software drivers and higher level compositional tools
    are also available for these, and are not for, say, the uVAX II.
    
    So Why would anyone want a Qbus to MIDI converter? I dont know...
    
    There's certainly plenty of I/O devices to start with. An old DEQNA
    would provide at least the DMA engine and a FIFO buffer for the
    MIDI data; "all" you'd have to do is modify the hardware to drive
    MIDI instead of Ethernet and rewrite the uP code to write or extract 
    and format the FIFO data...Likely extremely difficult, but not
    impossible from an archetecture standpoint. How about other modules?
    We have an IEE-488 bus driver, which is a serial bus talking to
    addressed devices; sure there will be hardware mods, but not as
    extensive as for the QNA. ALL our computers have RS serial lines
    which have a send and recieve circuit and baud rate. What would
    it take? Also, there are the parallel output I/O modules, which
    could drive a parallel to Serial (MIDI) converter board of some
    sort. All of the above would need a software driver to work at all,
    a task which could possibly exceed the hardware effort in itself.
    Still, even if all this were done, there are no high level "editors"
    for music set up to drive the driver of the converter option! But,
    it IS a VAX! (Mystique_Mystique)
    
    Oh well...Guess you could always go to the Amiga if you really want
    true multiprocessing; hear the notes sound as you plonk 'em down
    on the staff....
    
    	Joe Jas 

    Talk to Ron RKNRON::ROSS and Edd JAWS::COTE offline, they MAY 
    have something to say to you about this.
    
    karl

    You could buy a DZQ or DHQ for less than a QNA and convert it by
    building the opto isolator interface and changing the crystal to
    get the correct baud rate...both the DZQ and the DHQ even allow
    for non-standard cyrstals and baud rates....the DHQ is a DMA engine
    and the DZQ is not for those of you who are fussy about such things...
    
    dave

    
    I have designed and built a dual midi in,out, thru adaptor for the
    Qbus. Actually for the DLVJ1. 2 board etched set that will mount
    in the back of a BA123, or standalone.
    
    (At first I just modified the DL, but then thought folks
    would think that less desirable cause of servicing, etc.,
    so now there are no DLV mods other than a wire wrap or 2...)
    
    Ive written programs mainly for sending/recieving midi streams,
    and saving real-time system exclusive messages to disk. (RT11 and C)
    I save all my voice data and backup sequences on floppy (or other
    device...)
    
    Where is the market for this? Im not sure. Even tho, there
    are quite a few micro-11s or lsi 11s, and a growing # of uVAXes
    out there, I guess its a hobbiest kinda thing.
    
    I have sold a couple tho....
    
    rr
    
    
    
        

    There is a usenix proceddings that outlines how someone did this
    (midi to mvax2), complete with software and schematics.
    If you are interested, email me you request and I will interoffice
    mail it.
    

    sure. why not.
    
    Ron Ross
    mlo 1-2 C31
    
    

    
    	Say, could I also get a copy of that?
    
    					Tnx,
    
    					   Rich