Since I have recently been playing Harvey Headbanger from the Eprom version (and also loaded from tape) I have noticed something that never occured to me in the 80's
It is physically impossible to play the game on a CPC with 2 Joysticks.
Redefining the keys for Player 1 is fine, but there are some restrictions placed on the keys that can be used for the 2nd player, and this prevents a 2nd Joystick from being used. Does anyone know why this restriction exists? It's even mentioned in the instructions that "restrictions" are placed on the key selection for Player 2 (and only Player 2, Play 1 can use any keys or joystick they like)
I have tried setting player 1 up with joystick 2, all good, except then player 2 has restrictions that prevent the selection of Joystick 1.
Very odd. Has anyone examined the code to see why this behaves this way, and more importantly perhaps patchand fix it? It cannot be program size, I seem to remember even from tape it loads in only a few minutes and plays of a 464 so I doubt it is a hardware limitation, possibly just lazy coding.
Regards
Craig
Can you uses Joystick 2 for Player 1 and Joystick 1 for Player 2?
Restrictions are probably due to the fact the pressing of some keys also simulate the keypress of another (third of forth key).
Look here (0:45 or so):
Keyboard Clash CPC6128 (http://www.youtube.com/watch?v=wF0SbEJEO0A#)
You can download this utility from FutureOS - The revolutionary UltraOS for the CPC6128 and CPCPlus (http://www.futureos.de) to check which keys make problems.
An example by way of explanation...
If player 1 with a joystick presses up and right, and player 2 presses up on the other joystick, the CPC will also "read" player 2 as pressing right, even though they're not. This is obviously undesirable... ;)
The problem happens when 3 keys are pressed that form "3 corners of a square" in the keyboard row/column matrix, the 4th corner will be sensed as a phantom keypress. As the joysticks are wired as normal keys, just on two different rows, it's very likely that the players will experience clash.
For the original amstrad joystick with pass through (and more modern keyboards), there are diodes to stop this effect from happening, so maybe the code is just buggy and then hadn't realised that someone might actually use a genuine joystick... :)
Quote from: ralferoo on 20:16, 18 May 14
An example by way of explanation...
If player 1 with a joystick presses up and right, and player 2 presses up on the other joystick, the CPC will also "read" player 2 as pressing right, even though they're not. This is obviously undesirable... ;)
The problem happens when 3 keys are pressed that form "3 corners of a square" in the keyboard row/column matrix, the 4th corner will be sensed as a phantom keypress. As the joysticks are wired as normal keys, just on two different rows, it's very likely that the players will experience clash.
For the original amstrad joystick with pass through (and more modern keyboards), there are diodes to stop this effect from happening, so maybe the code is just buggy and then hadn't realised that someone might actually use a genuine joystick... :)
Arrrggghhhh Damn Keyboard clash... I never realised it ran into the Joysticks too.. While at university I handed in many assignments and projects refering to "correct powert" ;) I really hope that this can be fixed. I'd love to play against my son (Now 4) on the GX4000 control pads LOL Perhaps he might beat me (even quicker) then.Craig
I'd never encountered it on the CPC until I got it out again recently and ended up constantly typing "liwst" :P
I became a proper touch typist sometime after the last time I'd used it, so I'd never used the keyboard fast enough to generate the phantom keys before...