diff --git a/lib/opcode80.asm b/lib/opcode80.asm
index 28412a9..1334f61 100644
--- a/lib/opcode80.asm
+++ b/lib/opcode80.asm
@@ -9,18 +9,38 @@
 ; 0x00      none
 ; 0x1n      reg8, opcode |= (reg8 << n)
 ; 0x2n      reg16, opcode |= (reg8 << n)
-; 0x3n      3-bit number, opcode |= (num << n)
+; 0x3n      reg16b, opcode |= (reg8 << n)
+; 0x7n      3-bit number, opcode |= (num << n)
 ; 0x80      imm8, encoded as extra byte
 ; 0x81      imm16, encoded as extra word
 
-reg8:
-  db "B",0,"C",0,"D",0,"E",0,"H",0,"L",0,"M",0
-
-reg16:
-  db "BC", "DE", "HL", "SP"
+registers:
+.reg8:
+  db "B", 0
+  db "C", 0
+  db "D", 0
+  db "E", 0
+  db "H", 0
+  db "L", 0
+  db "M", 0
+  db 0
+.reg16:
+  db "BC", 0
+  db "DE", 0
+  db "HL", 0
+  db "SP", 0
+  db 0
+.reg16b:
+  db "BC", 0
+  db "DE", 0
+  db "HL", 0
+  db "AF", 0
+  db 0
+.end:
+  db 0
 
 opcodes:
-; Data movement
+  ; Data movement
   db 3, "MOV",  0b01000000, 0x13, 0x10
   db 3, "MVI",  0b00000110, 0x13, 0x80
   db 3, "LXI",  0b00000001, 0x24, 0x81
@@ -32,7 +52,7 @@ opcodes:
   db 4, "STAX", 0b00000010, 0x24, 0x00
   db 4, "XCHG", 0b11101011, 0x00, 0x00
 
-; Addition / Subtraction
+  ; Addition / Subtraction
   db 3, "ADD",  0b10000000, 0x10, 0x00
   db 3, "ADI",  0b11000110, 0x80, 0x00
   db 3, "ADC",  0b10001000, 0x10, 0x00
@@ -47,10 +67,10 @@ opcodes:
   db 3, "DCX",  0b00001011, 0x24, 0x00
   db 3, "DAD",  0b00001001, 0x24, 0x00
 
-; BCD
+  ; BCD
   db 3, "DAA",  0b00100111, 0x00, 0x00
 
-; Bitwise operations
+  ; Bitwise operations
   db 3, "ANA",  0b10100000, 0x10, 0x00
   db 3, "ANI",  0b11100110, 0x80, 0x00
   db 3, "ORA",  0b10110000, 0x10, 0x00
@@ -60,18 +80,18 @@ opcodes:
   db 3, "CMP",  0b10111000, 0x10, 0x00
   db 3, "CPI",  0b11111110, 0x80, 0x00
 
-; Rotate
+  ; Rotate
   db 3, "RLC",  0b00000111, 0x00, 0x00
   db 3, "RRC",  0b00001111, 0x00, 0x00
   db 3, "RAL",  0b00010111, 0x00, 0x00
   db 3, "RAR",  0b00011111, 0x00, 0x00
 
-; Complement
+  ; Complement
   db 3, "CMA",  0b00101111, 0x00, 0x00
   db 3, "CMC",  0b00111111, 0x00, 0x00
   db 3, "STC",  0b00110111, 0x00, 0x00
 
-; Jump
+  ; Jump
   db 3, "JMP",  0b11000011, 0x81, 0x00
   db 3, "JNZ",  0b11000010, 0x81, 0x00
   db 2, "JZ",   0b11001010, 0x81, 0x00
@@ -82,7 +102,7 @@ opcodes:
   db 2, "JP",   0b11110010, 0x81, 0x00
   db 2, "JM",   0b11111010, 0x81, 0x00
 
-; Call
+  ; Call
   db 4, "CALL", 0b11001101, 0x81, 0x00
   db 3, "CNZ",  0b11000100, 0x81, 0x00
   db 2, "CZ",   0b11001100, 0x81, 0x00
@@ -93,7 +113,7 @@ opcodes:
   db 2, "CP",   0b11110100, 0x81, 0x00
   db 2, "CM",   0b11111100, 0x81, 0x00
 
-; Return
+  ; Return
   db 3, "RET",  0b11001001, 0x00, 0x00
   db 3, "RNZ",  0b11000000, 0x00, 0x00
   db 2, "RZ",   0b11001000, 0x00, 0x00
@@ -104,10 +124,10 @@ opcodes:
   db 2, "RP",   0b11110000, 0x00, 0x00
   db 2, "RM",   0b11111000, 0x00, 0x00
 
-  db 3, "RST",  0b11000111, 0x33, 0x00
+  db 3, "RST",  0b11000111, 0x73, 0x00
   db 4, "PCHL", 0b11101001, 0x00, 0x00
-  db 4, "PUSH", 0b11000101, 0x24, 0x00
-  db 3, "POP",  0b11000001, 0x24, 0x00
+  db 4, "PUSH", 0b11000101, 0x34, 0x00
+  db 3, "POP",  0b11000001, 0x34, 0x00
   db 4, "XTHL", 0b11100011, 0x00, 0x00
   db 4, "SPHL", 0b11111001, 0x00, 0x00