SPUI is a DotCommand for the ZX Spectrum Next. It's primary (sole?) purpose is to make the creation of User Interaction flows from NextBASIC (a) more convenient; (b) less ugly; (c) more consistent; (d) less effort!

.SPUI -h will get you the built-in help.

When building GUIs the parameter is compulsory.

To prevent unexpected side effects, unless instructed, you should preload Register 0x7F with 0.

See the /docs/ folder

--Xalior, 20200626