moved most of the CLR and NEW commands to Mega65 extra ROM segment

c64/basic/basic_do_new.s

@@ -0,0 +1,90 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# M65 *       #TAKE
+// #LAYOUT# X16 BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+
+basic_do_new:	
+
+#if (ROM_LAYOUT_M65 && SEGMENT_BASIC_0)
+
+	jsr     map_BASIC_1
+	jsr_ind VB1__basic_do_new
+	jmp     map_NORMAL
+
+basic_do_clr:
+
+	jsr     map_BASIC_1
+	jsr_ind VB1__basic_do_clr
+	jmp     map_NORMAL
+
+#else
+
+	// Setup pointers to memory storage  XXX should depend on text start vector
+	lda #<$0801
+	sta TXTTAB+0
+	lda #>$0801
+	sta TXTTAB+1
+	sta VARTAB+1
+	lda #<$0803
+	sta VARTAB+0
+
+	// Zero line pointer
+	// XXX - We should also zero $0800, i.e., TXTTAB - 1
+	ldy #$00
+	tya
+	sta (TXTTAB),y
+	iny
+	sta (TXTTAB),y
+	
+	
+	// Get top of memory.
+	// If a cart is present, then it is $7FFF,
+	// if not, then it is $F7FF, since we support having
+	// programs and variables under ROM.
+	// i.e., we support 56KB RAM for BASIC, keeping some space
+	// free for some optimisation structures, e.g., FOR/NEXT loop
+	// records (without them going on the stack), GOSUB stack
+	// (same story), expression value cache?
+
+	sec			// Read, not write value
+	jsr JMEMTOP
+	cpx #$80
+	beq !+
+#if CONFIG_MEMORY_MODEL_60K
+	lda #>$F7FF
+#else // CONFIG_MEMORY_MODEL_38K
+	lda #>$A000
+#endif
+	.byte $2C
+!:	
+#if CONFIG_MEMORY_MODEL_60K
+	lda #>$F7FF
+#else // CONFIG_MEMORY_MODEL_38K
+	lda #>$A000
+#endif
+	sta MEMSIZ+1
+	sta FRETOP+1
+#if CONFIG_MEMORY_MODEL_60K
+	lda #<$F7FF
+#else // CONFIG_MEMORY_MODEL_38K
+	lda #<$A000
+#endif
+	sta MEMSIZ+0
+	sta FRETOP+0
+
+	// FALL THROUGH
+
+basic_do_clr:
+
+	// Clear variables, arrays and strings
+	lda VARTAB+0
+	sta ARYTAB+0
+	sta STREND+0
+	lda VARTAB+1
+	sta ARYTAB+1
+	sta STREND+1
+
+	rts
+
+#endif // ROM layout