2018-11-25, 07:07 PM
Couple of ideas.
If your main loop is fairly short, you could have it call a keyscan routing and update a global variable as to what it found - and then reference this variable each time, rather than scanning each time.
If it's not short, or doesn't do scanning often enough, then you could do what sinclair did - have an interrupt routing that scans the keyboard 50 times a second and updates a variable with the result.
If you are running with standard ROM and interrupts on, you can of course always read the last keypress from the system variables. I did that with Berksman, so the last direction you chose is the one you move when you get to the corner. Even if you don't get there for a couple of seconds - press up, and let go of the keys, and you'll still turn upwards. Lastkey is a system variable described in the sinclair manual.
If your main loop is fairly short, you could have it call a keyscan routing and update a global variable as to what it found - and then reference this variable each time, rather than scanning each time.
If it's not short, or doesn't do scanning often enough, then you could do what sinclair did - have an interrupt routing that scans the keyboard 50 times a second and updates a variable with the result.
If you are running with standard ROM and interrupts on, you can of course always read the last keypress from the system variables. I did that with Berksman, so the last direction you chose is the one you move when you get to the corner. Even if you don't get there for a couple of seconds - press up, and let go of the keys, and you'll still turn upwards. Lastkey is a system variable described in the sinclair manual.