*
*``````````````````````````````*
* TVLIN :: TEXT VERTICAL LINE  *
*-                            -*
* CREATES A VERTICAL LINE OF   *
* TEXT COMPOSED OF THE FILL    *
* CHARACTER SPECIFIED AT X.    *
*-                            -*
* CLOBBERS:                    *
*                              *
* FLAGS:  ????----  REG: AXYM  *
*-                            -*
* CYCLES: ???                  *
* SIZE:                        *
*-                            -*
* USAGE:                       *
*        LDA (Y-START)         *
*        PHA                   *
*        LDA (Y-END)           *
*        PHA                   *
*        LDA (X-POS)           *
*        PHA                   *
*        LDA (FILL CHAR)       *
*        PHA                   *
*        JSR TVLIN             *
*-                            -*
* ENTRY                        *
*                              *
* TOP OF STACK                 *
*                              *
* LOW BYTE OF RETURN ADDRESS   *
* HI BYTE OF RETURN ADDRESS    *
* XPOS START OF LINE (:Y1)     *
* XPOS END OF LINE (:Y2)       *
* YPOS OF LINE (:X)            *
* FILL CHARACTER (:F)          *
*-                            -*
* EXIT                         *
*                              *
* TOP OF STACK                 *
*                              *
* LOW BYTE OF RETURN ADDRESS   *
* HI BYTE OF RETURN ADDRESS    *
*                              *
*   Y = END OF LINE            *
*   X = HORIZONTAL POSITION    *
*   A = LOW BYTE OF RET ADDR   *
*,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,*
*
TVLIN
*
** SAVE RETURN ADDRESS
*
                                PLA
                                STA   :RETADR
                                PLA
                                STA   :RETADR+1
*
** GET PARAMETERS
*
                                PLA
                                STA   :F         ; FILL CHAR
                                PLA
                                STA   :X         ; X POS
                                PLA
                                STA   :Y2        ; END
                                PLA
                                STA   :Y1        ; START
*
                                LDX   :X
                                LDY   :Y1
                                STY   CURSV
                                STX   CURSH
                                JSR   VTAB       ; SET CURSOR POS
:LOOP
                                JSR   COUT1      ; PRINT CHAR
                                LDX   :X
                                STX   CURSH
                                STY   CURSV
                                JSR   VTAB       ; SET NEW CURSOR POS
                                LDA   :F         ; RELOAD FILL CHAR
                                INY              ; INCREASE COUNTER
                                CPY   :Y2        ; IF Y1 < Y2
                                BNE   :LOOP      ; LOOP; ELSE, CONTINUE
:EXIT
*
** RESTORE RETURN ADDRESS
*
                                LDA   :RETADR+1
                                PHA
                                LDA   :RETADR
                                PHA
*
                                RTS
*
** DATA
*
:RETADR        DS            2
:X                            DS    1
:Y1                          DS    1
:Y2                          DS    1
:F                            DS    1