That further means, that it's only machine and not human-readable other than from within the *NextBASIC Editor*. These two *dot commands* allow *NextBASIC* to be exported to a text file to be edited by a more specialised programmer's editor, or shared with other, non Sinclair computers and imported back in a form that the NextBasic Editor can understand. **.browse** One of the nicest features of the *Browser* is its built-in file dialogs. **.browse** allows these to be used within your *NextBASIC* programs and pass the selected file to a string variable in your program saving immense amounts of time from programming menu-based navigation. **.defrag** *NextZXOS* provides a streaming API which can be used for audio or video. If the files however are not defragmented, streaming is interrupted. **.defrag** solves this problem rearranging the file in question to be in one, continuous, piece. **.editprefs /.browseprefs** NextZXOS's native customisers for the editor and the browser. **.guide** **.gde** is the official documentation NextZXOS file format and NextGuide is its viewer. It's a hypertext viewer partially compatible with the Amiga Guide Format **.install/.uninstall** These are the *dot commands* to *install* and *remove* drivers like for example the *mouse driver* from the system. *NextZXOS* provides a driver API, which you can use to write your own drivers which is used in conjunction with the new **DRIVER** command. **.lfn** This is a very special use case command; its sole purpose is to return the long file name for a short (8+3) filename. **.lfn** does not work on *IDEDOS/+3DOS* drives, or rather it does work but returns the same name as *+3DOS* drives only accept 8+3 filenames. **.mem** Returns the free memory for *NextZXOS* and *NextBASIC* use **.nextver** Assigns the current version of *NextZXOS* to a variable we specify. **.unzip** Native decompressor for **.zip archives** > **Notes** > > Any errors generated by a *NextZXOS* dot command generate an error code of **255** (**Dot**\ > **Command Error**) which can be read with the **ERROR. ERROR$** and **ERROR TO**\ > commands. Refer to *Chapter 1* for details. ### Modifying the startup – Autoexec.bas *NextZXOS* provides you with a very fast way to set up your *NextBASIC* and *NextZXOS* environment upon boot by using commands stored in a special file called **autoexec.bas** located inside the **c:/nextzxos/** folder. The same rules apply as with regular **SAVE**, meaning you will need to give a **LINE** parameter to save it before it can auto execute. If you omit the **LINE** parameter, the commands will auto load upon boot but won't execute. For example to set up a red background with bright white letters upon boot: