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General Category => Amstrad CPC hardware => Topic started by: Emashzed on 13:06, 11 July 18

Title: AMX Mouse calibration
Post by: Emashzed on 13:06, 11 July 18
Hi guys !


I have recently got myself a classic AMX Mouse for my CPC.
Unfortunately, its calibration seems to be way off: it takes a crazy amount of movement to move the cursor a couple centimeters in Advanced OCP Art Studio. I did clean the insides carefully.
Inside the mouse, there appear to be 4 potentiometers, but I have no idea which does what, and messing with them seemed to do more harm than good (but it did have an effect on the cursor movements)
Does anyone have pointers (ha ha) on how to make my mouse good as new ?


Cheers  :)
Title: Re: AMX Mouse calibration
Post by: rpalmer on 13:36, 11 July 18
Why not just note where they were and start moving them to see what they result in. Then just adjust as to your needs.

As you said they did affect the movement of the cursor, so that should give you a hint as to what they do.

rpalmer
Title: Re: AMX Mouse calibration
Post by: Bryce on 14:24, 11 July 18
Can you take some close up pictures of the components on the PCB? Then it might be possible to tell you what the pots actually do.

Bryce.
Title: Re: AMX Mouse calibration
Post by: GUNHED on 15:12, 11 July 18
Try to hold down Shift or Control while moving the mouse, this will speed it up.
Title: Re: AMX Mouse calibration
Post by: Emashzed on 01:55, 12 July 18
Thanks for all the suggestions guys


@Bryce (http://www.cpcwiki.eu/forum/index.php?action=profile;u=225): I have uploaded a couple pics here: https://imgur.com/a/siBM85n  If they're any useful, I guess it may be worth uploading them to the wiki too ? If the pics are not clear enough, do tell, I'll try and grab better ones.


@rpalmer (http://www.cpcwiki.eu/forum/index.php?action=profile;u=379): Definitely trying to do that, but I'm having a hard time reaching a good result. I do need to try some more though. I also thought it would be worth having this discussion here, for documentation purposes. I do see a lot of mouse related threads these days...


@GUNHED (http://www.cpcwiki.eu/forum/index.php?action=profile;u=2029): this is a very nice tip, good to know, but I do wish to restore my AMX mouse to its former glory rather than just use a workaround.

Title: Re: AMX Mouse calibration
Post by: Bryce on 09:36, 12 July 18
Those pictures are fine: The pots are adjusting the output pulse of the IR receiver diodes. Changing these won't have any effect on the cursor movement. There is nothing on that PCB that could effect the speed or sensitivity of the mouse.


Bryce.
Title: Re: AMX Mouse calibration
Post by: GUNHED on 17:27, 12 July 18
Well, correct me if I'm wrong. If software like AMX studio does check the joystick/mouse more often (not only 50 or 300 mickeys) like they do, then an increased pulse would lead to enhanced movements. So IMHO it would be interesting to adjust this potis.  :)
Title: Re: AMX Mouse calibration
Post by: Bryce on 11:50, 13 July 18
Well, correct me if I'm wrong. If software like AMX studio does check the joystick/mouse more often (not only 50 or 300 mickeys) like they do, then an increased pulse would lead to enhanced movements. So IMHO it would be interesting to adjust this potis.  :)

You are wrong :) . Or to be fair, I think you just mis-understood what the pots do. The "pulses per cm" speed is determined by the little wheel full of slots which is non-adjustable. The pots only set the bias value of the sensor, it won't cause more pulses to be sent.

If you set the pot too far in one direction it will stop sending pulses completely because it no longer detects the light. If you set it too far in the other direction it will possibly send pulses even when the mouse isn't moved because it detects the stray light bouncing around inside the mouse.

Bryce.