| Routines

0DAF: THE 'CLEARING THE WHOLE DISPLAY AREA' SUBROUTINE

Used by the routines at CLS, MAIN_EXEC and AUTO_LIST.
CL_ALL | 0DAF | LD HL,$0000 | The system variable COORDS is reset to zero.
| 0DB2 | LD ($5C7D),HL
| 0DB5 | RES 0,(IY+$30) | Signal 'the screen is clear' (reset bit 0 of FLAGS2).
| 0DB9 | CALL CL_CHAN | Perform the 'house keeping' tasks.
| 0DBC | LD A,$FE | Open channel 'S'.
| 0DBE | CALL CHAN_OPEN
| 0DC1 | CALL TEMPS | Use the 'permanent' values.
| 0DC4 | LD B,$18 | Now 'clear' the 24 lines of the display.
| 0DC6 | CALL CL_LINE
| 0DC9 | LD HL,($5C51) | Ensure that the current output address (at (CURCHL)) is PRINT_OUT.
| 0DCC | LD DE,$09F4
| 0DCF | LD (HL),E
| 0DD0 | INC HL
| 0DD1 | LD (HL),D
| 0DD2 | LD (IY+$52),$01 | Reset the scroll counter (SCR-CT).
| 0DD6 | LD BC,$1821 | As the upper part of the display is being handled the 'upper print line' will be line 0.
This routine continues into CL_SET.