Comment on IBM PS/2 Keyboard ModificationparentComments−bogantech4yIt is two way, but the clock is always provided by the keyboard.PS/2 devices all have pull-up resistors as the only thing driving the lines high are those resistors.The mcu on either side only ever pull it low and never high.http://www.lucadavidian.com/2017/11/15/interfacing-ps2-keybo...−userbinator4yThen perhaps IBM's keyboards somehow push the clock closer to the limit (16.7kHz, I believe) than motherboards' controllers can handle? Unfortunately I wasn't able to find any measurements of different keyboards' clock frequencies.
Comments
It is two way, but the clock is always provided by the keyboard.
PS/2 devices all have pull-up resistors as the only thing driving the lines high are those resistors.
The mcu on either side only ever pull it low and never high.
http://www.lucadavidian.com/2017/11/15/interfacing-ps2-keybo...
Then perhaps IBM's keyboards somehow push the clock closer to the limit (16.7kHz, I believe) than motherboards' controllers can handle? Unfortunately I wasn't able to find any measurements of different keyboards' clock frequencies.