Buttons

There are three physical buttons supported, each with two logical functions on shift click and long press. The buttons act as VT220 4.15 User Defined Keys.

However they are numbered from 0, not 17 as on the original VT220. The logical functions (click/long press) are thus programmed by referencing button number 0/1, 2/3 and 4/5 respectively.

Furthermore, on reset however, the these keys are bound to ARROWUP/ARROWLEFT, ENTER/ESC and to ARROWDOWN/ARROWRIGHT respectively which should work pretty well for a lot of menu applications.

Print screen

CSI 0 i (Media copy) will send the screen content back over the serial line, bracketed in paste mode CSI 200 ~ and CSI 201 ~. Note: Lines are truncated after the last printable non-empty character on the line. By definition, only printable characters and newline will be sent back - tab etc will have already been converted to spaces.

This is effectively a memory dump of the terminal buffer. It is used in the unit tests (tests/automated), but can be used in applications as well - it is not intended to be an internal only function.

Character encoding

There is no Latin-1 / ISO 8859 support - the terminal will happily accept you switching to e.g. swedish character encoding, but will still only ever interpret non-ascii characters as UTF-8 (or Dec Special Character Set).

Screen size

The screen size is rarely 80x24 characters. The current screen size can be queried CSI 18 t, which will be replied to with CSI 8; height; width t.