Dashboard: DIALS (Part 2 of 4)

       Name: DIALS (Part 2 of 4)                                     [Show more]
       Type: Subroutine
   Category: Dashboard
    Summary: Update the dashboard: pitch and roll indicators
  Deep dive: The dashboard indicators
    Context: See this subroutine in context in the source code
 References: No direct references to this subroutine in this source file


 LDA #WHITE             ; Set COL to white to use as the colour for the pitch
 STA COL                ; and roll indicators

 LDA ALP1               ; Fetch the roll angle alpha as a value between 0 and
 LSR A                  ; 31, and divide by 2 to get a value of 0 to 15

 BIT ALP2+1             ; Set the N flag according to the opposite sign of the
                        ; roll angle, which is stored in ALP2+1

 JSR DIS5               ; Call DIS5 with Y = 1 to draw the roll indicator using
                        ; a range of 0-15, and increment Y to 2 to point to the
                        ; next indicator (the pitch indicator)

 LDA BET1               ; Fetch the magnitude of the pitch angle beta as a
 ASL A                  ; positive value between 0 and 8, and multiply by 2 to
                        ; get a value of 0 to 16

 BIT BET2               ; Set the N flag according to the sign of the pitch
                        ; angle, which is stored in BET2

 JSR DIS5               ; Call DIS5 with Y = 2 to draw the pitch indicator using
                        ; a range of 0-15, and increment Y to 3 to point to the
                        ; next indicator (the bottom of the four energy banks)