On Mon, May 18, 2020 at 6:47 PM sales--- via cctalk <cctalk@classiccmp.org> wrote: > On 2020-05-18 17:34, Steve Malikoff via cctalk wrote: > > There is a project that seems to be going along the same idea, > > http://www.kbdbabel.org/ > > > > Steve. > > Except that I can tell you from experience that not all 4p4c terminal > keyboards are interchangeable. I you plug a Wyse into a Televideo, or > vice versa, the keyboard will not work, and sometimes causes a small > fire....
That is very true. DEC LK201/LK401, etc, and compatibles are all +12V devices with +12V and gnd on specific pins (not mirrored or mirror-safe). I have, as I mentioned, a Planar terminal, an ELT-320. It is a third-party device with an LK201 socket (and a PC-AT keyboard socket - either one can be used). Other vendors are free to do as they please because they expect to sell you a device with their keyboard. I'm sure some are +5V devices and many are +12V. Doesn't take much of a difference to cause problems, especially if your +12V line isn't current-limited. Making a universal keyboard interface definitely faces some physical challenges. -ethan
