added panic screen, added versioning mechanism proposal

c64/basic/init/basic_cold_start_internal.s

@@ -0,0 +1,36 @@
+
+//
+// Continuation of the BASIC cold start routine
+//
+
+basic_cold_start_internal:
+
+	// Setup vectors at $300
+	ldy #$0B
+!:
+	lda basic_vector_defaults_1, y
+	sta IERROR, y
+	dey
+	bpl !-
+
+	// Setup misc vectors
+	ldy #$04
+!:
+	lda basic_vector_defaults_2, y
+	sta ADRAY1, y
+	dey
+	bpl !-
+
+	// Setup USRPOK
+	lda #$4C // JMP opcode
+	sta USRPOK
+	lda #<do_ILLEGAL_QUANTITY_error
+	sta USRADD+0
+	lda #>do_ILLEGAL_QUANTITY_error
+	sta USRADD+1
+
+	// Print startup messages
+	jsr INITMSG
+
+	// jump into warm start loop
+	jmp basic_warm_start