implemented some missing parts for 46K/50K/60K memory models

src/basic/engine_variables/assign_variable.s

@@ -115,7 +115,14 @@ assign_variable_common_1:
 	// Get array address
 
 	jsr find_array
+	bcc !+
 
+	// Array does not exist - we will have to create one with default parameters
+
+	// XXX implement this
+
+	jmp do_NOT_IMPLEMENTED_error
+!:
 	// Fetch the number of dimensions
 
 	pla

src/basic/engine_variables/fetch_variable_arr.s

@@ -101,15 +101,18 @@ fetch_variable_arr_calc_pos_loop:
 
 #if CONFIG_MEMORY_MODEL_60K
 	
-	// XXX
-	// XXX
-	// XXX
+	ldx #<VARPNT
+
+	jsr peek_under_roms
+	sta __FAC1+3
+	iny
+	jsr peek_under_roms
+	sta __FAC1+4
+	iny
 
 #elif CONFIG_MEMORY_MODEL_46K || CONFIG_MEMORY_MODEL_50K
 
-	// XXX
-	// XXX
-	// XXX
+	jsr helper_array_fetch_dimension
 
 #else // CONFIG_MEMORY_MODEL_38
 

src/basic/engine_variables/helper_array_fetch_dimension_46K_50K.s

@@ -0,0 +1,32 @@
+// #LAYOUT# STD *       #TAKE-HIGH
+// #LAYOUT# *   BASIC_0 #TAKE-HIGH
+// #LAYOUT# *   *       #IGNORE
+
+// This has to go $E000 or above - routine below banks out the main BASIC ROM!
+
+#if CONFIG_MEMORY_MODEL_46K || CONFIG_MEMORY_MODEL_50K
+
+helper_array_fetch_dimension:
+
+	// Unmap BASIC lower ROM
+
+	lda #$26
+	sta CPU_R6510
+
+	// Fetch the dimension
+
+	lda (VARPNT), y
+	sta __FAC1+3
+	iny
+	lda (VARPNT), y
+	sta __FAC1+4
+	iny
+
+	// Restore default memory mapping
+
+	lda #$27
+	sta CPU_R6510
+
+	rts
+
+#endif