      FileType FF7  BBC Font Sequence of VDU operations
1- 94 Vector &17 UKVDU23V
1- 97 Vector &1B VDUXV
1-527 VDU Drivers
1-548 VDU 0   Null operation
1-549 VDU 1   CTRL+A  Send next character to printer only (if enabled)
1-550 VDU 2   CTRL+B  Enable printer; characters go to printer and screen
1-551 VDU 3   CTRL+C  Disable printer stream (see VDU 2)
1-552 VDU 4   CTRL+D  Text is printed at the text cursor position
1-553 VDU 5   CTRL+E  Text is printed at the graphics cursor position
1-554 VDU 6   CTRL+F  Enable VDU driver (see VDU 21)
1-555 VDU 7   CTRL+G  Bell
1-556 VDU 8   CTRL+H  Cursor Left (and delete also, during input)
1-557 VDU 9   CTRL+I  Cursor Right (horizontal tab)
1-558 VDU 10  CTRL+J  Cursor Down (Line Feed)
1-559 VDU 11  CTRL+K  Cursor Up (vertical tab)
1-560 VDU 12  CTRL+K  Clear Screen (form feed)
1-561 VDU 13  CTRL+M  Carriage Return
1-562 VDU 14  CTRL+N  Enter Paged Mode (see VDU 15)
1-563 VDU 15  CTRL+O  Disable Paged Mode (see VDU 14)
1-564 VDU 16  CTRL+P  Clear Graphics Window
1-565 VDU 17  CTRL+Q  Set text fore/background colour
1-566 VDU 18  CTRL+R  Set graphics colour and action
1-568 VDU 19  CTRL+S  Redefine logical colour (set palette)
1-572 VDU 20  CTRL+T  Restore default palette and colours
1-573 VDU 21  CTRL+U  Disable text and graphics output (see VDU 6)
1-574 VDU 22  CTRL+V  Change screen mode
1-579 VDU 23  Miscellaneous commands
1-580 VDU 23,0     Set interlace and control cursor appearance
1-581 VDU 23,1     Control the appearance of the text cursor
1-582 VDU 23,2-5   Define ECF pattern and colours
1-583 VDU 23,6     Set dot-dash line style
1-584 VDU 23,7     Scroll text window or screen
1-586 VDU 23,8     Clear a block of the text window
1-588 VDU 23,9     Set flash time for first flashing colour
1-589 VDU 23,10    Set flash time for second flashing colour
1-590 VDU 23,11    Set default patterns
1-592 VDU 23,12-15 Define simple ECF patterns and colours
1-594 VDU 23,16    Control the movement of the cursor after printing
1-596 VDU 23,17,0-3 Set the tint for a colour
1-597 VDU 23,17,4  Choose the patterns used to interpret VDU 23,2-5 calls
1-598 VDU 23,17,5  Exchange text foreground and background colours
1-599 VDU 23,17,6  Set ECF origin
1-600 VDU 23,17,7  Set character size/spacing
1-605 VDU 23,32-355 Redefine the printable characters
1-607 Table - VDU 25 PLOT codes
1-607 VDU 25  General PLOT command
1-608 VDU 24  Define graphics window
1-610 VDU 26  Restore default text and graphics windows
1-611 VDU 27  Null operation
1-612 VDU 28  Define text window
1-613 VDU 29  Set graphics origin
1-614 VDU 30  Move text cursor home (0,0)
1-615 VDU 31  Move text cursor to (x,y)
1-616 VDU 127 Delete
1-639 OS_Byte 112 &70 Write VDU Driver Screen Bank
1-645 OS_Byte 117 &75 Read VDU Status
1-652 OS_Byte 160 &A0 Read VDU variable Value
1-669 OS_Byte 218 &DA Bytes In VDU Queue
1-671 OS_Byte 250 &FA Read VDU Driver Screen Bank Number
1-703 SWI &31    OS_ReadVduVariables
1-745 VDU 23,27    Sprite manager
3-403 VDU 23,17,56-56 Font manager
4-551 VDU codes table
