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Keyboard: TT214

[Commodore 64 version]

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 ;PHA ; source ;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