;Screen Control Assembly Lanuage Routines for Apple 1

        SUBROUTINE _SCREEN

SMTEXT  EQU $00     ;Default Text Screen
SMWIDE  EQU $FF     ;Wide Text Screen (Undefined)

;Set Screen Mode
SETSCR: CMP SMTEXT  ;If Default Text Screen
        BEQ GETSCR  ;Return Return 0
        LDA #$FF    ;Else Return ERROR
        RTS
                    ;Else Return 0
;Get Screen Mode
GETSCR: LDA #0      ;Return 0 (Default Text Mode)
        RTS

;Clear the Screen
CLRSCR: RTS         ;Do Nothing (Drop to RTS)

;Move Cursor Home
CRSRHM  EQU CLRSCR  ;No Action

;Move Cursor to Specified Coordinates
SETPOS  EQU CLRSCR  ;No Action
 
;Get Cursor Position
GETPOS: LDA #$FF   ;Return Error 
        TAY
        RTS

;Get Screen Size
GETSIZ: LDA #40     ;40 Columns
        LDY #24     ;24 Lines
        RTS