> On Dec 27, 2019, at 3:10 PM, Glen Slick via cctalk <cctalk@classiccmp.org>
> wrote:
>
>>> Supplies of good non-USB PC keyboards are probably beginning to get harder
>>> to find now too...
>>
>> True. It could use either kind of keyboard. Also, USB to mini-DIN adapters
>> are still sold ($5 in the current L-Com catalog). That seems like a cheaper
>> solution than a USB Host shield.
>>
>
> If you mean one of these, they are just passive adapters that only
> work if the USB keyboard (or mouse) is capable of supporting both USB
> and PS/2 interfaces.
>
> http://www.l-com.com/usb-usb-adapter-type-a-female-mini-din-6-male
>
> I imagine the majority of cheap disposable keyboards manufactured now
> are USB only devices, not combination USB - PS/2 compatible devices
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. So I have to assume both
of those devices have a bit of logic inside. A simple USB chip easily fits,
consider the FTDI USB UART devices that are just tiny chips encapsulated in the
USB connector.
paul
