Difference between revisions of "Analog Joysticks"

Revision as of 15:05, 5 February 2010

The CPC+ and GX4000 contain an analog joystick port (additionally to the normal Digital Joystick port).

Technical

The connector is similar as PC/Soundblaster joystick ports, for details on the pin-outs (and differences between CPC and PC joysticks), see:

• 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= [maybe 0 ohm???], 3Fh=Right= [maybe 1xx Kohm???])
 6809h  ADC1  Analogue Joystick 1, Y-Axis (00h=Up=   [maybe 0 ohm???], 3Fh=Down = [maybe 1xx Kohm???])
 680Ah  ADC2  --unknown: MIGHT be Analogue Joystick 2, X-Axis (or Y-Axis, or whatever)
 680Bh  ADC3  --unknown: MIGHT be Analogue Joystick 2, Y-Axis (or X-Axis, or whatever)
 680Ch  ADC4  --unknown: MIGHT be unused (maybe wired to GND or VCC)
 680Dh  ADC5  --unknown: MIGHT be unused (maybe wired to GND or VCC)
 680Eh  ADC6  --unknown: MIGHT be unused (maybe wired to GND or VCC)
 680Fh  ADC7  --unknown: MIGHT be unused (maybe wired to GND or VCC)

To read that registers: Unlock the ASIC, and then map its register to memory at 4000h..7FFFh.

Analog CPC+ Joysticks

Every PC analog joystick can be used with the CPC Plus

CPC+ Games with Analog Joystick Support

Tennis Cup 2 ( Cartridge ) allows player 2 to use analog port.

MacDeath comment :

I tested it with a Trust Predator Lite PC analog joystick (4 button, 15pin socket).

Seems to actually work a little.

Yet I found out that it was impossible to go to directions Down and Right (yet Up and Left worked), Posible cause of failure are  :

• this PC analog joystick is of a slightly more recent generation (yet still using 15pin plug) and the standard in PC may have changed (Analog joysticks needed their own drivers to work on old windows PC).

• 4 button joystick, while Amstrad would support only 2 button (yet 2 analogue joystick as impliyed in connector pin-out).

• incompatibility between PC analogue joysticks and the actually unreleased Amstrad GX4000/Plus analogue joystick standard.

Tests have to be done with an older 2 button PC analog joystick, and further researchs on the matter.

As while CPC era Joystick were less subject to exotic settings, more modern era joystick often had to feature their own drivers on PC (Win95+ era) as manufacturers often included more buttons or Autofires, having to rely on non standards Pin-out setting.

The same case appears when you try to use a Sega Genesis/Megadrive controller on a CPC, as those have more buttons than the mundane Atari standards.

Yet if you manage to find an old 2 button PC analog Joystick, and actually own a GX4000/Plus with the Tennis Cup 2 Cartridge, it's worth giving it a try for the fun of it.

Also if you manage to get your hands on such Joystick actually working well on GX4000/Plus, tell us.

CPC+ Software with Analog Joystick Support

• FutureOS (Plus version)