Difference between revisions of "Analog Joysticks"

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(Analog CPC+ Joysticks)
(Analog CPC+ Joysticks)
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== Analog CPC+ Joysticks ==
 
== Analog CPC+ Joysticks ==
  
Currently, the only known CPC+ compatible analogue joysticks is the Sinclar SPJ-1 for PC200. The PC200 (PC-8) compatibility is also stated in the official [[Original Arnold V Specs]].
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Analogue joysticks confirmed to be compatible with the CPC+:
 
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* [[ Amstrad Analogue Joystick AJ-5]]
<gallery caption="SPJ-1 Sinclar Professional Joystick">
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* [[ Sinclair SPJ-1]]
Image:Joystick SPJ-1 with Box.jpg|SPJ-1 with Box
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Image:Joystick SPJ-1 Booklet.jpg|SPJ-1 Booklet
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</gallery>
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The SPJ-1 (Sinclair Professional Joystick) was produced to accompany [[Amstrad]]'s unsuccessful Sinclair PC200 (an old PC with 8086 processor). The SPJ-1 was a fully-fledged analogue joystick, with potentiometers used to measure input (rather than switches as in its digital precessors). It was probably a rebadged PC-standard device. The SPJ-1 was, like its host machine, a flop, and today appears to be exceptionally rare.
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[[Amstrad Analogue Joystick AJ-5]]
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== Analog PC Joysticks ==
 
== Analog PC Joysticks ==

Revision as of 04:49, 19 March 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:

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=180K ohm)
 6809h  ADC1  Analogue Joystick 1, Y-Axis (00h=Up  =0 ohm, 3Fh=Down =180K ohm)
 680Ah  ADC2  Analogue Joystick 2, X-Axis (00h=Left=0 ohm, 3Fh=Right=180K ohm)
 680Bh  ADC3  Analogue Joystick 2, Y-Axis (00h=Up  =0 ohm, 3Fh=Down =180K 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.

Analog CPC+ Joysticks

Analogue joysticks confirmed to be compatible with the CPC+:

Analog PC Joysticks

Analog PC Joysticks have a very similar 15pin connector. Theoretically, a few PC joysticks might be CPC+ compatible. However, in practice, this is rather unlikely - the potentiometers must have correct value, the button common pin must be correct, and the joystick may not contain additional electronics like auto-fire circuits, electrolyte capacitors, or digital-switch to analog-signal converters.

  • Caution - compared with PCs, the CPC+/GX4000 do output reversed polarity on the joysticks power supply pins, so any special electronics in PC joysticks may get destroyed when connecting them to a CPC Plus/GX4000.

If you want to use a PC joystick: Remove any electronics other than the potentiometers and buttons. Ensure that buttons are wired to correct common pin. And, probably you'd need to replace the potentiometers (if they aren't 180K) - however, this may be the complicated part: potentiometers in analog joysticks aren't necessarily matching standard mechanical dimensions.

CPC+ Software with Analog Joystick Support

  • 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
  • FutureOS - homebrew operating system (Plus version)