Break key

From BeebWiki

A filing system can be selected by pressing a key at the same time as pressing Break.

        Filing    Equivalent     FS
  KEY   System     Command      Number
----------------------------------------------
   A    ADFS       *ADFS         &08
   B
   C    CoProFS    *COPROFS      &0B
   D    DFS        *DISK, *DISC  &04
   E
   F    ADFS       *FADFS        &08
   G
   H    HADFS      *HADFS        &10
   I
   J
   K
   L    LVFS       *LVFS         &0A
   L    LFS        *LFS          &5C (65Link)
   M
   N    NFS        *NET          &05
   O
   P
   Q    VFS        *LVFS         &0A
   R    RAMFS      *RAM          &0C
   S
   T    TELESOFT   *TELESOFT     &06
   U  
   V    VFS        *VFS          &0A
   W
   X
   Y
   Z    DFS                      &04 (8271 Emulation)
   
  TAB   HostFS     *HOSTFS       &09
 SPACE  TFS        *TAPE         &01,&02
SHF/SPC RFS/ROMFS  *ROM          &03 
   
        IEEEFS     *IEEEFS       &07
        HostFS     *HOSTFS       &09
        DOSFS      *DOS          &1D
        BeebItFS   *BFS          &47