> On Dec 28, 2019, at 5:25 AM, Pete Turnbull via cctalk <cctalk@classiccmp.org>
> wrote:
>
> On 28/12/2019 01:46, Paul Koning via cctalk wrote:
>
>> I can get one and test it with an Apple keyboard, but that doesn't sound
>> right. There aren't enough wires on a USB connector to allow you to speak
>> the PS/2 protocol. And there are PS/2 to USB adapters (for old keyboards)
>> that are the same size; clearly the old keyboards don't speak USB.
>
> Enough wires? +5V, ground, clock, data vs +5V, ground, D+, D-
>
> Those old adapters are definitely just passive wiring, and were commonly
> supplied with dual-standard mice. That's why they're green. I worked in the
> IT department of a large university and it caused a lot of confusion back in
> the day when they were common, when people expected them to convert any
> keyboard or mouse to PS/2, and found they didn't. They only work with devices
> that inherently support both protocols.
Ok, it sounds like I jumped to conclusions on insufficient data. It sure is
amazing to speak two so unrelated protocols on the same wires and somehow make
it work.
paul
