diff --git a/sys/dev/ic/i8259reg.h b/sys/dev/ic/i8259reg.h
index 2e3caa1522d4..2203486e6d37 100644
--- a/sys/dev/ic/i8259reg.h
+++ b/sys/dev/ic/i8259reg.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: i8259reg.h,v 1.1 2001/06/21 03:43:43 thorpej Exp $	*/
+/*	$NetBSD: i8259reg.h,v 1.2 2001/06/21 18:57:04 thorpej Exp $	*/
 
 /*-
  * Copyright (c) 2001 The NetBSD Foundation, Inc.
@@ -55,16 +55,17 @@
 #define	PIC_ICW1	0x00	/* Initialization Command Word 1 (w) */
 #define	ICW1_IC4	(1U << 0)	/* ICW4 Write Required */
 #define	ICW1_SNGL	(1U << 1)	/* 1 == single, 0 == cascade */
-#define	ICW1_ADI	(1U << 2)	/* XXX */
+#define	ICW1_ADI	(1U << 2)	/* CALL address interval */
 #define	ICW1_LTIM	(1U << 3)	/* 1 == intrs are level trigger */
-#define	ICW_SELECT(x)	((x) << 4)	/* select ICW */
+#define	ICW1_SELECT	(1U << 4)	/* select ICW1 */
+#define	ICW1_IVA(x)	((x) << 5)	/* interrupt vector address (MCS-80) */
 
 #define	PIC_ICW2	0x01	/* Initialization Command Word 2 (w) */
 #define	ICW2_VECTOR(x)	((x) & 0xf8)	/* vector base address */
 #define	ICW2_IRL(x)	((x) << 0)	/* interrupt request level */
 
 #define	PIC_ICW3	0x01	/* Initialization Command Word 3 (w) */
-#define	ICW3_CASCADE	(1U << 2)	/* cascaded mode enable */
+#define	ICW3_CASCADE(x)	(1U << (x))	/* cascaded mode enable */
 #define	ICW3_SIC(x)	((x) << 0)	/* slave identifcation code */
 
 #define	PIC_ICW4	0x01	/* Initialization Command Word 4 (w) */
@@ -82,26 +83,20 @@
 
 #define	PIC_OCW2	0x00	/* Operational Control Word 2 (w) */
 #define	OCW2_SELECT	(0)		/* select OCW2 */
-#define	OCW2_OP(x)	((x) << 5)	/* operation; see below */
+#define	OCW3_EOI	(1U << 5)	/* EOI */
+#define	OCW3_SL		(1U << 6)	/* specific */
+#define	OCW3_R		(1U << 7)	/* rotate */
 #define	OCW2_ILS(x)	((x) << 0)	/* interrupt level select */
 
-#define	OCW2_OP_CLR_ROTATE_IN_AUTO_EOI_MODE	0
-#define	OCW2_OP_NON_SPECIFIC_EOI_CMD		1
-#define	OCW2_OP_NOOP				2
-#define	OCW2_OP_SPECIFIC_EOI_CMD		3
-#define	OCW2_OP_SET_ROTATE_IN_AUTO_EOI_MODE	4
-#define	OCW2_OP_ROTATE_ON_NON_SPEC_EOI_CMD	5
-#define	OCW2_OP_SET_PRIORITY_CMD		6
-#define	OCW2_OP_ROTATE_ON_SPEC_EOI_CMD		7
-
 #define	PIC_OCW3	0x00	/* Operational Control Word 3 (r/w) */
-#define	OCW3_SMM	(1U << 6)	/* special mask mode */
-#define	OCW3_ESMM	(1U << 5)	/* enable special mask mode */
+#define	OCW3_SSMM	(1U << 6)	/* set special mask mode */
+#define	OCW3_SMM	(1U << 5)	/* 1 = enable smm, 0 = disable */
 #define	OCW3_SELECT	(1U << 3)	/* select OCW3 */
 #define	OCW3_POLL	(1U << 2)	/* poll mode command */
-#define	OCW3_RR_CMD(x)	((x) << 0)	/* register read command */
+#define	OCW3_RR		(1U << 1)	/* register read */
+#define	OCW3_RIS	(1U << 0)	/* 1 = read IS, 0 = read IR */
 
-#define	OCW3_RR_CMD_READ_IRQ	2
-#define	OCW3_RR_CMD_READ_IS	3
+#define	OCW3_POLL_IRQ(x) ((x) & 0x7f)
+#define	OCW3_POLL_PENDING (1U << 7)
 
 #endif /* _DEV_IC_I8259REG_H_ */