| Routines

03503: THE 'CLEARING THE WHOLE DISPLAY AREA' SUBROUTINE

Used by the routines at CLS, MAIN_EXEC and AUTO_LIST.
CL_ALL | 03503 | LD HL,0 | The system variable COORDS is reset to zero.
| 03506 | LD (23677),HL
| 03509 | RES 0,(IY+48) | Signal 'the screen is clear' (reset bit 0 of FLAGS2).
| 03513 | CALL CL_CHAN | Perform the 'house keeping' tasks.
| 03516 | LD A,254 | Open channel 'S'.
| 03518 | CALL CHAN_OPEN
| 03521 | CALL TEMPS | Use the 'permanent' values.
| 03524 | LD B,24 | Now 'clear' the 24 lines of the display.
| 03526 | CALL CL_LINE
| 03529 | LD HL,(23633) | Ensure that the current output address (at (CURCHL)) is PRINT_OUT.
| 03532 | LD DE,2548
| 03535 | LD (HL),E
| 03536 | INC HL
| 03537 | LD (HL),D
| 03538 | LD (IY+82),1 | Reset the scroll counter (SCR-CT).
| 03542 | LD BC,6177 | As the upper part of the display is being handled the 'upper print line' will be line 0.
This routine continues into CL_SET.