The Psion Series 3 supported this kind of input as well. I discovered, as a result, that the password field on the lock screen used a simpler input method. Teenage-me thought that no one would guess a password if it included some characters that weren’t present on the keyboard and so you could put arbitrary numbers in the middle. It subsequently turned out that, although you could set such a password, you couldn’t then enter it to unlock the device.
If only USB 1.0 had had a provision for unicode code point input… we’d not be stuck with every os having a different key combination (sometimes a different one per app) for this.
But I’m not even certain unicode 2.0 (which introduced the code points > 16 bits) was released before usb 1.0… wikipedia puts them both in 1996.
USB HID is not much more abstract than trad keyboard scan codes. The mapping from keys to characters is still the responsibility of the OS, so that keyboard manufacturers can use the same electronics and firmware for all international keyboard layouts.
On my Linux Mint system, you can use ctrl-shift-U <unicode hex digits> <space> to type any Unicode code point. I don’t remember having to configure it, and it seems to work everywhere.
By contrast, the compose key is kind of a mess. It wasn’t enabled by default, but I figured out how to map <right alt> to <compose> on my US ASCII keyboard. After that, figuring out how to type various characters was more difficult, and is still an unsolved problem. The example you give works. The mappings are dependent on configuration and locale, but on my system I discovered they are defined in /usr/share/X11/locale/en_US.UTF-8/Compose. Interpreting what this file means is difficult. Here’s one entry:
That one is easy. If I type <RightAlt>=_ then I get ≡. Here’s another:
Compose:<Multi_key> <underscore> <U2260> : "≢" U2262 # _ ≠ NOT IDENTICAL TO
This one is impossible to type. I think I’m supposed to type <RightAlt>_≠ but there is no ≠ key on my keyboard and compose sequences cannot be nested. I don’t understand why there are 1,519 untypable compose sequences in this file.
The Psion Series 3 supported this kind of input as well. I discovered, as a result, that the password field on the lock screen used a simpler input method. Teenage-me thought that no one would guess a password if it included some characters that weren’t present on the keyboard and so you could put arbitrary numbers in the middle. It subsequently turned out that, although you could set such a password, you couldn’t then enter it to unlock the device.
Raymond’s brain should be added to the internet archive ;-)
Well, now I know, 15 years later or so. I always wondered why the prefixed
0would yield a different number.If only USB 1.0 had had a provision for unicode code point input… we’d not be stuck with every os having a different key combination (sometimes a different one per app) for this.
But I’m not even certain unicode 2.0 (which introduced the code points > 16 bits) was released before usb 1.0… wikipedia puts them both in 1996.
USB HID is not much more abstract than trad keyboard scan codes. The mapping from keys to characters is still the responsibility of the OS, so that keyboard manufacturers can use the same electronics and firmware for all international keyboard layouts.
On Unix systems, this problem is solved by the compose key. Here is a quick example: pressing it followed by
aand"results inä.On my Linux Mint system, you can use ctrl-shift-U <unicode hex digits> <space> to type any Unicode code point. I don’t remember having to configure it, and it seems to work everywhere.
By contrast, the compose key is kind of a mess. It wasn’t enabled by default, but I figured out how to map <right alt> to <compose> on my US ASCII keyboard. After that, figuring out how to type various characters was more difficult, and is still an unsolved problem. The example you give works. The mappings are dependent on configuration and locale, but on my system I discovered they are defined in
/usr/share/X11/locale/en_US.UTF-8/Compose. Interpreting what this file means is difficult. Here’s one entry:That one is easy. If I type <RightAlt>=_ then I get
≡. Here’s another:This one is impossible to type. I think I’m supposed to type <RightAlt>_≠ but there is no ≠ key on my keyboard and compose sequences cannot be nested. I don’t understand why there are 1,519 untypable compose sequences in this file.