Editing Atari interface (section)

==Paddles==
A paddle is a controller with a turnable knob that has stops.
The name comes from what they were initially ''used'' for: for moving a table tennis paddle on the screen in the game ''Pong''.
There were usually two Paddle controllers on a Y-cable to the same port.

Each paddle's knob is on a rotary potentiometer, connected to +5V at the right end and with the wiper connected to the pot line. Turning the knob right decreases the ''resistance''.
Note that ground is not connected: there is only a capacitor against ground for smoothing the signal.
The potentiometer does not alter the voltage but the ''current'' on the pin.
On original hardware, paddles were read relatively slowly by first letting the paddle charge a capacitor and then measuring the discharge time.
Modern adaptors that use an analog-to-digital converter connect the paddle as part of a voltage divider.

Paddles for the Commodore machines have the Atari pinout but the potentiometers are 470 kohm instead of 1 Mohm. This means that Atari paddles are usable on Commodore machines (only with less range) but not the other way around.<ref name="derogeepaddles">Projects of Jan Derogee — [https://home.kpn.nl/bderogee1980/projects/paddle/paddle.html C64 Paddles]. Retrieved 2018-05-23</ref>
The paddle interface was used also for pointing devices for the Commodore 64 and for analogue joysticks for the Commodore 64 and the Amiga.<ref name="elowaradcd">AmigaOS 3.5 Developer Docs — Amiga Hardware Reference Manual: Interface hardware: 
[http://amigadev.elowar.com/read/ADCD_2.1/Hardware_Manual_guide/node017D.html Controller Port Interface]. Retrieved 2018-04-18.</ref>