Drawing the screen: HGR

       Name: HGR                                                     [Show more]
       Type: Subroutine
   Category: Drawing the screen
    Summary: Switch to the high-resolution graphics screen mode
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * COLD calls HGR
             * TTX66K calls HGR


.HGR

 LDA $C054              ; Select page 1 display (i.e. main screen memory) by
                        ; reading the PAGE20FF soft switch

 LDA $C052              ; Configure graphics on the whole screen by reading the
                        ; MIXEDOFF soft switch

 LDA $C057              ; Select high-resolution graphics by reading the HIRESON
                        ; soft switch

 LDA $C050              ; Select the graphics mode by reading the TEXTOFF soft
                        ; switch

 LSR text               ; Clear bit 7 of text to indicate that we are now in the
                        ; high-resolution graphics screen mode

 RTS                    ; Return from the subroutine