Rename c1p target to osic1p

libsrc/osic1p/clrscr.s

@@ -0,0 +1,31 @@
+;
+; void clrscr (void);
+;
+        .export         _clrscr
+        .import         plot
+        .importzp       CURS_X, CURS_Y
+        .include        "osic1p.inc"
+
+; Adapted from the Challenger Character Graphics
+; Reference Manual, "2.3.3 MACHINE LANGUAGE SCREEN CLEAR"
+; This is self-modifying code!
+BANKS = VIDEORAMSIZE / $100
+
+_clrscr:
+        lda       #$20 ;' '
+		ldy       #BANKS
+		ldx       #$00
+staloc:
+		sta       SCRNBASE,X
+		inx
+		bne       staloc
+		inc       staloc+2
+		dey
+		bne       staloc
+		lda       #>(SCRNBASE); load high byte
+		sta       staloc+2    ; restore base address
+
+		lda       #$00        ; cursor in upper left corner
+        sta       CURS_X
+        sta       CURS_Y
+		jmp       plot        ; Set the cursor position