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Re: Wall Defence game for Apple II

winston19842005 wrote:

On 4/24/10 2:09 PM, in article
_vCdnZJ7Qblbrk7WnZ2dnUVZ_gSdnZ2d@giganews.com, "Michael J. Mahon"
<mjmahon@aol.com> wrote:


eriknoc wrote:

I like the idea of porting games to the Apple II series.  Nice work,
except it's very difficult to aim & control because he keeps moving,
and fast, and having to press another direction or key to make him
stop takes some of the fun away from playing the game IMHO.  Is this
how it works on ports to all the other systems?  I would have made it
to where letting go of a key or direction would make you stop and
holding it down would make you go.  That would make more sense to me
anyways.

That kind of control can be implemented on the Apple //e and later
machines, but the ][ and ][+, like many other computers of the day,
cannot sense when a key is released.


I'm trying to get my head around this statement...
Why not? What does the keyboard return after you stop pressing a key?
Does it not return a special value for "no key"?


On the //e and later machines, the encoder's "Any Key Down" level
is readable by the processor.  On earlier machines, it is not.

This allows a program to determine when no key is pressed.  If keys
are pressed in an "overlapping" fashion, so that there is always some
key pressed, then AKD does not allow key releases to be detected--only
"no key pressed" can be detected.

-michael

NadaNet 3.0 for Apple II parallel computing!
Home page:  http://home.comcast.net/~mjmahon/

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