Added bank-swapping routines (incomplete: doesn't implement memory map mode 1)

1 files changed, 27 insertions, 0 deletions

diff --git a/bankswap.c b/bankswap.c
new file mode 100644
index 0000000..4906667
--- /dev/null
+++ b/bankswap.c
@@ -0,0 +1,27 @@
+/* Memory bank swapping driver for 680 project.
+ *
+ * Copyright 2010, Duncan Smith
+ * GPL
+ */
+
+#include "asm_vars.h"
+
+void* pages[256];
+
+/* Address 0000 is always bound to ROM page 0. */
+
+/* Process orders to swap bank A (port 06, 0x4000). */
+void bankswap_4000_write(char data)
+{
+	mem_page_1 = pages[data];
+	mem_page_loc_1 = data;
+	return;
+}
+
+/* Process orders to swap bank B (port 07, 0x8000). */
+void bankswap_b_write(char data)
+{
+	mem_page_2 = pages[data];
+	mem_page_loc_2 = data;
+	return;
+}