added way to detect MEGA65 from the BASIC

src/basic/basic_commands/helper_if_mega65_46K_50K.s

@@ -0,0 +1,54 @@
+// #LAYOUT# M65 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_if_mega65:
+
+	// Unmap BASIC lower ROM
+
+	lda #$26
+	sta CPU_R6510
+
+	// Injest all spaces
+
+	ldy #$00
+!:
+	lda (TXTPTR), Y
+	cmp #$20
+	bne !+
+	inw TXTPTR
+	bra !-
+!:
+
+	// Check for MEGA65 untokenized keyword
+
+	ldy #$05
+!:
+	lda (TXTPTR), Y
+	cmp str_mega65, Y
+	bne_16 remap_BASIC_sec_rts
+	dey
+	bpl !-
+
+	// Increment TXTPTR by 6
+
+	clc
+	lda TXTPTR+0
+	adc #$06
+	sta TXTPTR+0
+	bcc !+
+	inc TXTPTR+1
+!:
+	// Report successful check
+
+	jmp remap_BASIC_clc_rts
+
+str_mega65:
+
+	.byte $4D, $45, $47, $41, $36, $35
+
+
+#endif