28 Dec
2019
28 Dec
'19
8:27 a.m.
On Dec 28, 2019, at 5:25 AM, Pete Turnbull via cctalk
<cctalk at classiccmp.org> wrote:
On 28/12/2019 01:46, Paul Koning via cctalk wrote:
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
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.