properly initialise memory when BASIC starts.

c64/basic/,aliases.s

@@ -24,7 +24,7 @@
 	.alias basic_end_of_arrays_ptr $31
 	.alias basic_start_of_free_space_ptr $31
 	.alias basic_start_of_strings_ptr $33
-	.alias basic_top_of_memory_ptr $35
+	.alias basic_top_of_memory_ptr $37
 	
 	.alias basic_numeric_work_area $57 ; $57 - $60 inclusive = 10 bytes
 

c64/basic/basic_main_loop.s

@@ -75,9 +75,6 @@ rsl_l1:	lda $0200,x
 	
 	jsr injest_number
 
-	lda tokenise_work1
-	sta $0427
-
 	;; Check if the number is a valid line number
 	;; i.e., 16 bits, no exponent, no decimal
 	lda basic_fac1_mantissa+2
@@ -90,7 +87,7 @@ ml_bad_line_number:
 	jmp do_basic_error
 *	lda tokenise_work4
 	cmp #$ff
-	beq ml_bad_line_number
+	bne ml_bad_line_number
 
 	;; Got a valid line number.
 

c64/basic/cmd_new.s

@@ -11,12 +11,34 @@ basic_do_new:
 	;; Setup pointers to memory storage
 	lda #<$0801
 	sta basic_start_of_text_ptr+0
-	lda >$0801
+	lda #>$0801
 	sta basic_start_of_text_ptr+1
 	sta basic_start_of_vars_ptr+1
 	lda #<$0803
 	sta basic_start_of_vars_ptr+0
 
+	;; 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 $ff99 		; KERNAL MEMTOP routine
+	cpx #$80
+	bne +
+	lda #>$f7ff
+	.byte $2c
+*	lda #>$7FFF
+	sta basic_top_of_memory_ptr+1
+	sta basic_start_of_strings_ptr+1
+	lda #<$f7ff
+	sta basic_top_of_memory_ptr+0
+	sta basic_start_of_strings_ptr+0	
+	
 	;; FALL THROUGH
 	
 basic_do_clr:

c64/basic/injest_number.s

@@ -15,7 +15,6 @@ ij_not_a_digit:
 	;; exponent or mantissa digits
 	
 	;; Look for decimal point
-	sta $0420
 	cmp #$2e
 	bne ij_not_decimal
 	lda tokenise_work4