TI-H: Re:

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TI-H: Re:


>Grant (who else) wrote:
>>You can easily make a 2 axis joystick for the calc using 2 caps
>>and a transistor...  I've already explained this.
>
>I don't recall that you ever mentioned this.  Why don't you post a
>schematic?

Oh yeah...  Everyone listens to off-topic mail, but not on-topic mail.

The APPLE II computer was one of the first to have a mouse and joystick
connected this way...

When a cap is at full charge, its at 5v.  When it is drained, its at about
.2.  If a transistor will react to an input voltage of 4.5 volts, every
time the voltage reaches 4.5 volts, a high signal is sent and then the cap
is drained.  There are special caps that turn without end and oscilate like
this.

Another way is to use a variable resistor with a high oscillation (it goes
from 1ohm to 5 ohms with 2mm of turn) rate and turns without end.  Then you
get a high/low pulse that can be read out of your calc...
References: