diff --git a/README.md b/README.md
index 5499ea1..0f9de05 100644
--- a/README.md
+++ b/README.md
@@ -44,12 +44,12 @@ You could use any HTTP server that sets these headers.
 
 | Name   | Address | Size / B | Access       |
 |--------|---------|----------|--------------|
-| TXBUF  | 0       | 32       | write        |
-| RXBUF  | 32      | 32       | read         |
-| TXHEAD | 64      | 1        | atomic read  |
-| TXTAIL | 65      | 1        | atomic write |
-| RXHEAD | 66      | 1        | atomic write |
-| RXTAIL | 67      | 1        | atomic read  |
+| TXBUF  | 00h     | 32       | write        |
+| RXBUF  | 20h     | 32       | read         |
+| TXHEAD | 40h     | 4        | atomic read  |
+| TXTAIL | 44h     | 4        | atomic write |
+| RXHEAD | 48h     | 4        | atomic write |
+| RXTAIL | 4Ch     | 4        | atomic read  |
 
 For both sending (`TX`) and receiving (`RX`), there are three
 registers: `xBUF`, `xHEAD` and `xTAIL`:
@@ -67,7 +67,7 @@ unoccupied byte between the tail and the head.
 
 | Name     | Address | Size / B | Access       |
 |----------|---------|----------|--------------|
-| SYSREADY | 68      | 1        | atomic write |
+| SYSREADY | 50h     | 1        | atomic write |
 
 The `SYSREADY` register is used to indicate when the system has booted
 up and is ready for user input.
diff --git a/emu.js b/emu.js
index bfbaf8f..0558a0d 100644
--- a/emu.js
+++ b/emu.js
@@ -1,14 +1,14 @@
-const TXBUF = 0;
-const RXBUF = 32;
-const TXHEAD = 64;
-const TXTAIL = 65;
-const RXHEAD = 66;
-const RXTAIL = 67;
-const SYSREADY = 68;
+const TXBUF = 0x00;
+const RXBUF = 0x20;
+const TXHEAD = 0x40;
+const TXTAIL = 0x44;
+const RXHEAD = 0x48;
+const RXTAIL = 0x4c;
+const SYSREADY = 0x50;
 
 const TXBUF_SIZE = 32;
 const RXBUF_SIZE = 32;
-const PERIPHS_SIZE = 69; // Nice
+const PERIPHS_SIZE = 81;
 
 const POLL_INTERVAL_MS = 20;
 
diff --git a/prelude.f b/prelude.f
index 8c2471c..098e418 100644
--- a/prelude.f
+++ b/prelude.f
@@ -63,18 +63,6 @@
 
 46 EMIT
 
-\ Peripheral register addresses
-
-: TXBUF 0 ;
-: RXBUF 32 ;
-: TXHEAD 64 ;
-: TXTAIL 65 ;
-: RXHEAD 66 ;
-: RXTAIL 67 ;
-: SYSREADY 68 ;
-
-46 EMIT
-
 \ Printing utilities
 
 : CR 10 EMIT ;
@@ -214,6 +202,22 @@ CHAR . EMIT
 
 CHAR . EMIT
 
+\ Peripheral register addresses
+
+HEX
+
+00 CONSTANT TXBUF
+20 CONSTANT RXBUF
+40 CONSTANT TXHEAD
+44 CONSTANT TXTAIL
+48 CONSTANT RXHEAD
+4C CONSTANT RXTAIL
+50 CONSTANT SYSREADY
+
+DECIMAL
+
+46 EMIT
+
 \ A better word-not-found handler
 
 : ANY-RX? RXHEAD AC@ RXTAIL AC@ <> ;
diff --git a/wipforth.wat b/wipforth.wat
index 20ad8e0..fb9e8f9 100644
--- a/wipforth.wat
+++ b/wipforth.wat
@@ -8,9 +8,9 @@
  (global $TXBUF  i32 (i32.const 0x0000))
  (global $RXBUF  i32 (i32.const 0x0020))
  (global $TXHEAD i32 (i32.const 0x0040))
- (global $TXTAIL i32 (i32.const 0x0041))
- (global $RXHEAD i32 (i32.const 0x0042))
- (global $RXTAIL i32 (i32.const 0x0043))
+ (global $TXTAIL i32 (i32.const 0x0044))
+ (global $RXHEAD i32 (i32.const 0x0048))
+ (global $RXTAIL i32 (i32.const 0x004c))
 
  ;; Forth registers
  (global $rsp (mut i32) (i32.const 0))