Quick example of how to clear the screen quickly.
READY.
MONITOR
MONITOR
PC SR AC XR YR SP
; FB000 00 00 00 00 F9
L"SCREENCLEAR",8
SEARCHING FOR SCREENCLEAR
LOADING
D $1800
. 01800 A9 00 LDA #$00
. 01802 A2 00 LDX #$00
. 01804 9D 00 04 STA $0400,X
. 01807 9D 00 05 STA $0500,X
. 0180A 9D 00 06 STA $0600,X
. 0180D 9D 00 07 STA $0700,X
. 01810 E8 INX
. 01811 D0 F1 BNE $1804
. 01813 60 RTS
. 01814 00 BRK
X