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Keyboard: KYTB

[BBC Micro disc version, Flight]

Name: KYTB [Show more] Type: Variable Category: Keyboard Summary: Lookup table for in-flight keyboard controls Deep dive: The key logger
Context: See this variable in context in the source code Variations: See code variations for this variable in the different versions References: This variable is used as follows: * DK4 uses KYTB * DKS1 uses KYTB * NO3 uses KYTB * SFRMIS uses KYTB

Keyboard table for in-flight controls. This table contains the internal key codes for the flight keys (see p.142 of the Advanced User Guide for a list of internal key numbers). The pitch, roll, speed and laser keys (i.e. the seven primary flight control keys) have bit 7 set, so they have 128 added to their internal values. This doesn't appear to be used anywhere. Note that KYTB actually points to the byte before the start of the table, so the offset of the first key value is 1 (i.e. KYTB+1), not 0.
Other entry points: KYTB Contains an RTS
.KYTB RTS \ Return from the subroutine (used as an entry point and \ a fall-through from above) \ These are the primary flight controls (pitch, roll, \ speed and lasers): EQUB &68 + 128 \ ? KYTB+1 Slow down EQUB &62 + 128 \ Space KYTB+2 Speed up EQUB &66 + 128 \ < KYTB+3 Roll left EQUB &67 + 128 \ > KYTB+4 Roll right EQUB &42 + 128 \ X KYTB+5 Pitch up EQUB &51 + 128 \ S KYTB+6 Pitch down EQUB &41 + 128 \ A KYTB+7 Fire lasers \ These are the secondary flight controls: EQUB &60 \ TAB KYTB+8 Energy bomb EQUB &70 \ ESCAPE KYTB+9 Launch escape pod EQUB &23 \ T KYTB+10 Arm missile EQUB &35 \ U KYTB+11 Unarm missile EQUB &65 \ M KYTB+12 Fire missile EQUB &22 \ E KYTB+13 E.C.M. EQUB &45 \ J KYTB+14 In-system jump EQUB &52 \ C KYTB+15 Docking computer EQUB &37 \ P KYTB+16 Cancel docking computer