USR (solved)

[zarsoft]

Where is the USR function?

[boriel]

The USR function is built-in (like RND, SIN, COS, etc).
Some functions are still built-in for performance or compatibility reasons.

For example, USR allows both numbers and strings.

USR "a" (returns the mem address of the 1st byte of UDG "a").
USR 32424 (executes machine code at 32424 and returns value stored in BC register).

[zarsoft]

Why USR does not appear in https://zxbasic.readthedocs.io/en/latest/identifier/ ?

[boriel]

Because it's not yet documented. I'll add it.
Thanks for reporting it.

[zarsoft]

If you don't have time to write the page,
then just add the word to the index.

[boriel]

Added: https://zxbasic.readthedocs.io/en/docs/usr/