Keyboard inverters/converters for terminals

On Thu, May 21, 2020 at 9:37 AM Electronics Plus via cctalk < cctalk at classiccmp.org> wrote: are selling passive adapters that work with ADDS 4000 terminals that use PS/2 protocol on a modular jack. As has been noted earlier in this thread, there are a huge number of computers that use modular plugs and jacks for keyboard interfaces, and there is NO standard for their electrical or protocol characteristics. Plugging in the wrong combination can result in damage to either or both devices. Even using the wrong modular cable can do that, because common 4P4C modular cables are wired with a flip (1 to 4, 2 to 3, etc), while modular cables for computers are sometimes (e.g. Macintosh 128/512/Plus) wired straight through (1 to 1, 2 to 2, etc.) IMNSHO, there's a special place in hell reserved for those who have designed equipment to (ab)use modular connectors other than for telephone lines and 10BASEx Ethernet, and I really think a better connector should have been chosen for 10BASEx. DEC using MMJ may get a pass because they at least attempted to prevent connecting the wrong stuff together.