== Technical ==
The connector is similar (but not compatible) as PC/Soundblaster joystick ports, for details on the pin-outs (and differences between CPC and PC joysticks), see:
* [[Connector:Analogue joystick (CPC Plus only)|Analog Joystick Port Pin-Outs]]
For info on reading the analog inputs, see [[Arnold V Specs Revised]] (though still unknown which of the eight ADC0..ADC7 inputs are mapped to the four X1,Y1,X2,Y2 pins...?)
The buttons are accessed same ways as for Digital Joysticks (ie. as part of the keyboard matrix).
The analog inputs are read from memory mapped ASIC registers:
6808h ADC0 Analogue Joystick 1, X-Axis (00h=Left=0 ohm, 3Fh=Right=138K ohm)
6809h ADC1 Analogue Joystick 1, Y-Axis (00h=Up =0 ohm, 3Fh=Down =138K ohm)
680Ah ADC2 Analogue Joystick 2, X-Axis (00h=Left=0 ohm, 3Fh=Right=138K ohm)
680Bh ADC3 Analogue Joystick 2, Y-Axis (00h=Up =0 ohm, 3Fh=Down =138K ohm)
680Ch ADC4 Unused, wired to +5V (twice the maximum of 2.5V) (returns 3Fh)
680Dh ADC5 Unused, wired to GND (equivalent to 0 ohm) (returns 00h)
680Eh ADC6 Unused, wired to +5V (twice the maximum of 2.5V) (returns 3Fh)
680Fh ADC7 Unused, wired to GND (equivalent to 0 ohm) (returns 00h)
To read that registers: Unlock the ASIC, and then map its register to memory at 4000h..7FFFh.
Values measured by Octoate:
ADC input at 00h..01h = 0 Ohm (left/up)
ADC input at 1Fh..20h = 50 kOhm (center) (that is, the center of ADC values, not of the resistor values)
ADC input at 3Eh..3Fh = 138 kOhm (right/down)
== Analog CPC+ Joysticks ==
Were there Analogue joysticks confirmed to be compatible with the CPC+:* [[Amstrad Analogue Joystick AJ-5]]* [[Sinclair SPJ-1|Amstrad's Sinclair SPJ-1]] Arnold 5 Diagnostic cart test results - {| class="wikitable"|-! Manufacturer !! Model !! Fire Common !! Resistor !! Centre X !! Centre Y !! X Axis min !! X Axis max !! Y Axis min !! Y Axis max !! Ref !! Notes|-| Quickshot || QS-6219 || Pin 4 || TBC || &1a-&27 || &1c-2b || &00-&0f || &2c-&33 || &00-&12 || &31-&35 || dthrone || Ranges correspond to x and y axis adjust sliders|} == Analog PC Joysticks == Analog PC Joysticks have a very similar 15pin connector. But with some differences, which cause compatibility problems. Statistically, many people reported the analog PC joysticks '''do work''' with analog CPC+ software. Many other people reported it won't work - though it's quite possibly that they simply made some fundamental mistakes (like trying to use "digital" 15pin joysticks as "analog" joystick, or that they didn't even had proper CPC+ software for testing). * '''Button Common Pin''' - In PCs, the button-common-pin can be at Pin4 or Pin5, on the CPC+ it must be Pin4 (or Pin12 for 3rd-4th button; if any manufactured). If necessary, rewire that pins. * '''Reversed Supply Voltages''' - Compared with PC Gameports, the +5V and GND are connected vice-versa in the CPC+. This is no problem for the potentiometers (both PC and CPC+ use Pin1 as pot-common). However, it is a problem if the joystick contains '''additional electronics''' (auto-fire circuits, electrolyte capacitors, circuits inside of ''digital'' joysticks/gamepads that do emulate analog signals, etc.) These won't work (and may get damaged by the reversed voltages). If necessary, remove any such electronics before connected the joystick to the CPC+. * '''Resistor Values''' - In PCs, the A/D conversion is done by software timings, meaning the PCs could handle joysticks with different potentiometer types (anything from 10 kiloohm to many megaohm should work). The CPC+ does the A/D conversion by hardware, this requires less CPU load, but it also means that it requires fixed potentiometer types (circa '''138k'''Ω).** Analog PC joysticks are reportedly most commonly using '''100k''', '''120k''', or '''150k'''Ω pots. These types should be more or less compatible with the CPC+ (100K/120K won't reach the ADC=3Fh max value, for example, resolution might be only ADC=00h..30h. And 150K would be clipped to ADC=3Fh for anything above 138kΩ).** To handle those different pot types, CPC+ software should include calibration options.** There are also some PC joysticks with incompatible pot types like '''300k'''Ω - these won't work (since values above 138k will be clipped).? == CPC+ Software with Analog Joystick Support == * [[FutureOS]] - (Plus version)* [[Tennis Cup 2 ( Cartridge )]] - allows to use Analog Joystick (as digital joystick replacement in two-player mode, selectable in options menu - the game merely emulates digital inputs, it doesn't actually support analog input)* RP11 Arnold V diagnostic ROM cartridge - allows to display the eight ADC inputs in numeric form
== CPC+ Games with Analog Joystick Support ==
Were there any released...?[[Category:CPC Plus]][[Category:FutureOS]][[Category:Games Programming]][[Category:Input Device]][[Category:Peripherals]]