diff --git a/cpu.c b/cpu.c
index 770206d..a8c6ceb 100644
--- a/cpu.c
+++ b/cpu.c
@@ -26,20 +26,18 @@ struct registers {
 struct registers regs;
 
 enum addressing_mode {
-	AM_ACCUMULATOR,
-	AM_IMMEDIATE,
-	AM_ZERO_PAGE,
-	AM_ZERO_PAGE_X,
-	AM_ZERO_PAGE_Y,
-	AM_RELATIVE,
-	AM_ABSOLUTE,
-	AM_ABSOLUTE_X,
-	AM_ABSOLUTE_Y,
-	AM_INDIRECT,
-	AM_INDIRECT_X,
-	AM_INDIRECT_Y,
-	AM_INDEXED_INDIRECT,
-	AM_INDIRECT_INDEXED,
+	AM_ACC,
+	AM_IMM,
+	AM_ZP,
+	AM_ZP_X,
+	AM_ZP_Y,
+	AM_REL,
+	AM_ABS,
+	AM_ABS_X,
+	AM_ABS_Y,
+	AM_IND,
+	AM_IND_X,
+	AM_IND_Y,
 };
 
 /* 64K address space, 16bit words */
@@ -98,28 +96,28 @@ lda(enum addressing_mode mode)
 	arg = peek(regs.pc++);
 
 	switch (mode) {
-	case AM_IMMEDIATE:	/* $A9 */
+	case AM_IMM:	/* $A9 */
 		val = arg;
 		break;
-	case AM_ZERO_PAGE:	/* $A5 */
+	case AM_ZP:	/* $A5 */
 		val = peek(arg % 256);
 		break;
-	case AM_ABSOLUTE:	/* $AD */
+	case AM_ABS:	/* $AD */
 		val = peek(arg);
 		break;
-	case AM_ZERO_PAGE_X:	/* $B5 */
+	case AM_ZP_X:	/* $B5 */
 		val = peek((arg + regs.x) % 256);
 		break;
-	case AM_ABSOLUTE_X:	/* $BD */
+	case AM_ABS_X:	/* $BD */
 		val = peek(arg + regs.x);
 		break;
-	case AM_ABSOLUTE_Y:	/* $B9 */
+	case AM_ABS_Y:	/* $B9 */
 		val = peek(arg + regs.y);
 		break;
-	case AM_INDIRECT_X:	/* $A1 */
+	case AM_IND_X:	/* $A1 */
 		val = peek(peek((arg + regs.x) % 256) + peek((arg + regs.x + 1) % 256) * 256);
 		break;
-	case AM_INDIRECT_Y:	/* $B1 */
+	case AM_IND_Y:	/* $B1 */
 		val = peek(peek(arg) + peek((arg + 1) % 256) * 256 + regs.y);
 		break;
 	default:
@@ -149,31 +147,31 @@ interpret(void)
 			brk();
 			return;
 		case 0xa1:
-			lda(AM_INDIRECT_X);
+			lda(AM_IND_X);
 			break;
 		case 0xa5:
-			lda(AM_ZERO_PAGE);
+			lda(AM_ZP);
 			break;
 		case 0xa9:
-			lda(AM_IMMEDIATE);
+			lda(AM_IMM);
 			break;
 		case 0xaa:
 			tax();
 			break;
 		case 0xad:
-			lda(AM_ABSOLUTE);
+			lda(AM_ABS);
 			break;
 		case 0xb1:
-			lda(AM_INDIRECT_Y);
+			lda(AM_IND_Y);
 			break;
 		case 0xb5:
-			lda(AM_ZERO_PAGE_X);
+			lda(AM_ZP_X);
 			break;
 		case 0xb9:
-			lda(AM_ABSOLUTE_Y);
+			lda(AM_ABS_Y);
 			break;
 		case 0xbd:
-			lda(AM_ABSOLUTE_X);
+			lda(AM_ABS_X);
 			break;
 		case 0xe8:
 			inx();