diff --git a/kernel/pic.c b/kernel/pic.c
index 119b363..8b661b6 100644
--- a/kernel/pic.c
+++ b/kernel/pic.c
@@ -32,6 +32,7 @@ void pic_remap(uint offset_1, uint offset_2) {
 }
 
 // disable the PIC
+// will probably never use this.
 void pic_disable() {
 	outb(PIC1_DATA, 0xff);
 	outb(PIC2_DATA, 0xff);
diff --git a/kernel/pic.h b/kernel/pic.h
index db6d4ee..04f4fa2 100644
--- a/kernel/pic.h
+++ b/kernel/pic.h
@@ -11,6 +11,7 @@
 #define PIC2_CMD	PIC2
 #define PIC2_DATA	(PIC2+1)
 
+// ICWx
 #define ICW1_ICW4		0x01
 #define ICW1_SINGLE		0x02
 #define ICW1_INTERVAL4	0x04
@@ -25,6 +26,10 @@
 
 #define ICW_INIT_MASK	(ICW1_INIT | ICW1_ICW4)
 
+// ISR & IRR
+#define PIC_R_IRR		0x0a
+#define PIC_R_ISR		0x0b
+
 // Ints
 #define PIC_EOI	0x20 // End-of-interupt