6 Nov
2011
6 Nov
'11
3:49 p.m.
On Nov 6, 2011, at 4:13 PM, cctech at vax-11.org wrote:
> How could a purely passive converter possibly work
with an original Model
> M? Surely a USB port is not going to accept the clock/data lines of a
> Type M on its differnetial data line pair?
>
> -tony
>
The keyboard decoder chip inside the keyboard can detect if it is connected to a passive
adapter plug and switch from USB to PS/2 mode.
Emphasis: *original* model M. Passive adaptors certainly won't let you plug an
original Model M into USB (or at least if they do, it won't give you a working USB
device). You'd need something to talk AT keyboard on one end and USB HID on the
other.
In the other direction with modern USB keyboards, you are exactly right.
- Dave