Re: [stella] stick/paddle combos

Subject: Re: [stella] stick/paddle combos
From: Greg Troutman <mor@xxxxxxx>
Date: Mon, 29 Sep 1997 23:45:37 -0700
Galen Tatsuo Komatsu wrote:
> 
> *note* I have yet to even try programming Stella.  Haven't had the time
> or the computer, and neglecting the lack of a certain hardware device
> forgot to grab the old Apple2 development software when Jim had it up on
> ftp.  (sorry, Jim.)   ...have even yet to try out all those games you guys
> posted to the list. =^(
> 
> > The Ikari warriors controllers have detents(sp?) like an old fashioned
> > channel selector on a TV.  It's not exactly the same as a true
> > paddle/stick combo.
> 
>         Assuming I know what you're talking about, yes they do.  Makes a
> nice "kachink" sound too since there's a bunch of metal parts in the
> mechanism. =^)  Those SNK sticks are just a regular joystick with the
> turning-thingy on top.  And when I think about it, I don't think the
> "paddle" part even registers distinct directions (I'll have to check my
> friend's one next time), it just has its detents set so that 8 clicks make
> a full circle.  I'd guess that it just signals when you've turned it a
> certain distance (compare the 2600 paddles and driving controllers.)
> ...someone, please correct me.

No, I think Glenn is right.  From what I can tell, the spinny part of
the Ikari Warriors stick is a 12 position rotary knob.  Functionally,
it's more like a 12-way joystick and an 8-way joystick combined into
one, rather than a stick and paddle.  The 2600 paddle controllers are
pots with many more possible read values, which is why they work so
great in games like Kaboom!  To do Kaboom! with the IW sticks, you'd
either have to spin them like 7 or 8 times to move all the way across
the screen, or have the buckets jerk along many pixels with each click.  
 
>         I was wondering how difficult it is to implement paddles since
> Glenn in an earlier message said they're sometimes difficult to get things
> working with.  However there's a number of Paddle games which implement
> all four pots (or there's a number of 4 player paddle games with really,
> really, really good programmers behind them)

All paddle game programmers are really good ;)  It's much more involved
than reading the positions of the joystick.  Because so many points of
contact exist on the pot, you are required to discharge a capacitor (by
writing to D7 of VBLANK, IIR), then start counting how long it takes for
the resistance of the pot to allow the input port to go to logic 1. The
amount of time will vary greatly, and you guage the position of each
paddle by this timing process.  In Kaboom!, it appears that the paddle
input ports are checked and a counter updated almost constantly while
the screen is being drawn.  This can really cramp your style... ;)

--
mor@xxxxxxx
http://www.crl.com/~mor/

--
Archives updated once/day at http://www.biglist.com/lists/stella/archives/
Unsubscribing and other info at http://www.biglist.com/lists/stella/stella.html

Current Thread