They are wholly independent from the protocol or interface. Ghosting is an electrical issue that is a result of keyboards being a bunch of switches arranged in a matrix. It makes the keyboard’s controller register an extra keypress in certain conditions. Nothing to do with how the thing communicates with the host computer.
Key rollover issues can be related to ghosting. The limit for it is once again the keyboard’s design at the circuit level, not its communication protocol.
Really they’re both related to how cheaply built the keyboard is. That’s the only thing.
Ghosting entirely depends on the wiring of the keyboard pcb. Key rollover can depend on the wiring of the keyboard pcb, but usually is limited by the usb HID protocol.
Generally speaking, usb can carry up to 6 keys of information in a single packet (I don’t remember off the top of my head if modifiers are included). It is possible to use extended packets and encode more info (and thus allow for more than 6 keys rollover) but it requires negotiation with the os so most vendors don’t bother as generally you don’t need to be able to press more than 6 keys at the same time for most applications.
I think it’s more of an issue for USB keyboards than PS/2 keyboards.
They are wholly independent from the protocol or interface. Ghosting is an electrical issue that is a result of keyboards being a bunch of switches arranged in a matrix. It makes the keyboard’s controller register an extra keypress in certain conditions. Nothing to do with how the thing communicates with the host computer.
Key rollover issues can be related to ghosting. The limit for it is once again the keyboard’s design at the circuit level, not its communication protocol.
Really they’re both related to how cheaply built the keyboard is. That’s the only thing.
Ghosting entirely depends on the wiring of the keyboard pcb. Key rollover can depend on the wiring of the keyboard pcb, but usually is limited by the usb HID protocol.
Generally speaking, usb can carry up to 6 keys of information in a single packet (I don’t remember off the top of my head if modifiers are included). It is possible to use extended packets and encode more info (and thus allow for more than 6 keys rollover) but it requires negotiation with the os so most vendors don’t bother as generally you don’t need to be able to press more than 6 keys at the same time for most applications.