Conference hydra::amiga_v1

    I have Fighter Duel, and just finished an analog joystick adapter for
    it.  I had no problem getting the digital stick to work, but it's VERY
    difficult to control without the analog type.

    Found the  problem thanks and thought I should write it up here for
    future Fighter Duel users.  It doesn't work at all well with PAL video. 
    The symptoms are:
    
    1. the bit-mapped password prompting text is almost unreadable
    2. the joystick doesn't work
    
    In an attempt to fix #1, i.e grabbed NTSC-PAL off an FF disk and set my
    2000 into NTSC mode.  This certainly fixed #1, and to  my surprise,
    also fixed #2.  I don't really understand how the NTSC/PAL setting is
    related to the joystick, but suffice to say, I'm now up and flying.
    
    I guess the next step is to build myself an analog joystick.  Did you
    take a standard IBM stick and adapt as detailed in 730.*?  Any problems
    with dynamic range, instability (capacitors required?) etc. that you
    think I should know about?

    I built my adapter according to the design in the July 89 issue of
    Amazing.  My version adds a switch to select either Low (standard IBM
    range) or Hi (compensated range) sensitivity, and another switch to
    swap the X-Y axis.  For Fighter Duel, I find the low range sensitivity
    works better, and it does need X and Y to be swapped as stated in the
    manual.

    Thanks for the info.  I knocked up a cable and got myself hold of a
    SUNCOM analog stick.  It sure makes a difference especially for
    elevator control.  I can finally land back on the carrier for
    re-fueling.
    
    However, when it comes to aileron control, I find it slightly
    unstable.  I can't get it to keep the wings level and fly totally
    unattended like I can with the digital stick.  I used the "centre
    stick" option while still on the deck, and successfully used the trim
    pots to trim for gross adjustments like torque induced roll.
    
    If I establish straight and level flight, do a simple shallow turn,
    and then attempt to level the wings it will always have a very slow
    roll in the direction of the last turn.  This then requires constant
    left<->right stick flicking (only tiny adjustments) to keep the wings
    level (not unlike real flying).
    
    I unplugged the joystick and stuck an ohmmeter across the +5V pin and
    the Y-pot pin.  It behaved pretty much as expected as I moved the stick
    left and right.  It also seemed to provide a rock steady resistance in
    the neutral postion, *but* this value was different depending on which
    direction I had previously moved the stick.  If I moved the stick left
    and then let it go it measured 51K.  If I moved the stick right and let
    it go it would measure 53K (I may have the directions back-to-front
    now, I can't remember).  Obviously I can adjust the actual value with
    the trim pot, but no matter what I set it to there was always a
    significant difference between "centre after being left" and "centre
    after being right".
    
    I repeated the experiment for the X-pot (i.e. elevator control) and
    found that it always returned to the exact same centre value, no matter
    how the stick had previously been moved (up, down, left or right).
    
    Using the very useful BASIC program posted in 730.?, I found that this
    Y-pot variation resulted in a variaion of 1 or 2 on the digital side. 
    This seems to explain the exact nature of my "slow roll" problem while
    flying, i.e. it always "slow rolls" in the direction of the last turn.
    
    Might I have just got myself a "sticky" joystick, or is this a "feature"
    of analog sticks?  There was also some mention of capacitors in 730,
    but I can't imagine they'd help, since the reading is rock steady once
    you let go of the stick, it's just that it's different depeding on
    where the stick has recently been.
                                                                          

    Sounds like you have a slight mechanical 'play' in the Y-axis pot
    mechanism. Maybe the left/right centering springs are a bit loose
    so the stick doesn't return to its exact center.