Keyboard: TT214

       Name: TT214                                                   [Show more]
       Type: Subroutine
   Category: Keyboard
    Summary: Ask a question with a "Y/N?" prompt and return the response
    Context: See this subroutine in context in the source code
 References: No direct references to this subroutine in this source file


 Arguments:

   A                    The text token to print before the "Y/N?" prompt


 Returns:

   C flag               Set if the response was "yes", clear otherwise


.TT214

;.TT214                 ; These instructions are commented out in the original
;                       ; source
;PHA
;JSR TT162
;PLA

.TT221

 JSR TT27               ; Print the text token in A

 LDA #206               ; Print extended token 206 ("{all caps}(Y/N)?")
 JSR DETOK

 JSR TT217              ; Scan the keyboard until a key is pressed, and return
                        ; the key's ASCII code in A and X

 ORA #%00100000         ; Set bit 5 in the value of the key pressed, which
                        ; converts it to lower case

 CMP #'y'               ; If "y" was pressed, jump to TT218
 BEQ TT218

 LDA #'n'               ; Otherwise jump to TT26 to print "n" and return from
 JMP TT26               ; the subroutine using a tail call (so all other
                        ; responses apart from "y" indicate a no)

.TT218

 JSR TT26               ; Print the character in A, i.e. print "y"

 SEC                    ; Set the C flag to indicate a "yes" response

 RTS                    ; Return from the subroutine