`*.??a` *Any filename* with *any type* that ends in the letter **a**\ `a*.???` *Any filename* starting with **a** with *any type*\ `??a.?b?` *Any* three letter *filename* ending with the letter **a** with a *type* having a **b** as second letter (for example **dba.dbf**) While these won't: `*d.*` **\*** not the last character in the *Name field*\ `*.scr.*` **\*** not the last character in the *Name field*\ `*.*d` **\*** not the last character in the *Type field* As it's apparent from the examples above, combinations of very few characters can represent a wide array of *filenames* which is exactly why *wildcards* are invaluable in managing our files. #### Filesystems We've also talked about *filesystems*; more specifically about *FAT* and *IDEDOS/+3DOS* but not specifically about what these represent. In a few words, a *filesystem* is a specific way of organising information that's located on a *storage medium*. There are *filesystems* that are medium–specific (for example even though it doesn't have a specific name, the way files are stored onto tape is a *filesystem* in itself) and *filesystems* geared toward general use. *NextZXOS* supports 3 (or rather 4) *filesystems*: the ZX Spectrum native tape *filesystem*, *+3DOS* (that comes from the ZX Spectrum +3[^p171-13] principally geared towards floppy disks), and two variants of the *FAT filesystem*, *FAT16* and *FAT32* (their main difference where *NextZXOS* is concerned is capacity). *FAT* is the de-facto standard *filesystem* for most modern removable media (like the SD cards the ZX Spectrum Next uses). Each *filesystem* has its pros and cons which affects slightly the way *NextZXOS* operates. As we've already noted earlier not all features are available on every supported *filesystem*; this obviously affects some of the features we'll examine below. *IDEDOS* (which comes from the +3e) is not a *filesystem* in itself but a scheme that allows multiple *+3DOS* "partitions" to occupy a single physical disk, in order to facilitate the use of large media like hard disks. #### Partitions In the introductory notes and the *Filenames* section, we've mentioned the term *partitions* either by themselves or in conjunction with one of the *filesystems* mentioned above e.g. *a FAT partition*. This is a bit misleading and in reality it's an acceptable mashing of two terms: *XXX filesystem type* AND *partition – a partition formatted with the XXX filesystem*. In other words a *FAT partition* is *a partition formatted with the FAT filesystem* (could be either *FAT16* or *FAT32* – using *FAT* as a portmanteau term is acceptable use). But what is a partition? Nothing more than an arbitrary slicing of available space on a storage medium, usually to make it more manageable. An SD card for example could have one or more *partitions* and not all of the same *filesystem*. Note here that *NextZXOS* will always start from the first *FAT partition* on the first SD card on the system. If you remember the initial discussion, *drives* can be assigned to *partitions*; this process of assigning a partition to a *drive* is called *mounting* and we will examine it right after we briefly examine *storage devices*. #### Storage devices and disks For *NextZXOS* a *storage device* can be *physical* or *virtual.* We use the term *disk* for both but the former refers to an actual, tangible piece of hardware like the SD Card reader your ZX Spectrum Next is equipped with, while the latter is nothing but a file containing the image of a *filesystem*. *NextZXOS* uses a common set of controls to address and access both types of disks. *Physical disks* are generally –with the exception of tape– assigned a number per device (ie. the primary SD card reader and secondary SD card reader have differ- [^p171-13]: *The +3DOS filesystem is identical to the CP/M one.*