From fec7798be959884d567319180a9fadcbd9381ef3 Mon Sep 17 00:00:00 2001
From: Roman Boykov <romychs@gmail.com>
Date: Fri, 17 Apr 2026 16:17:51 +0300
Subject: [PATCH] fix disassm bit ops

---
 dis/z80disasm.go      |  5 +++--
 dis/z80disasm_test.go | 23 +++++++++++++++++++++++
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/dis/z80disasm.go b/dis/z80disasm.go
index 7b35c66..be1b4d5 100644
--- a/dis/z80disasm.go
+++ b/dis/z80disasm.go
@@ -354,15 +354,16 @@ func (d *Disassembler) getRel() string {
 }
 
 var shiftOps = []string{"RLC", "RRC", "RL", "RR", "SLA", "SRA", "SLL", "SRL"}
+var bitOps = []string{"BIT", "RES", "SET"}
 
 // opocodeCB disassemble Z80 Opcodes, with CB first byte
 func (d *Disassembler) opocodeCB() string {
 	op := ""
 	opcode := d.getByte()
 	if opcode <= 0x3F {
-		op = shiftOps[opcode>>3&0x07] + operands[opcode&0x7]
+		op = shiftOps[opcode>>3&0x07] + sep + operands[opcode&0x7]
 	} else {
-		op = shiftOps[(opcode>>6&0x03)-1] + operands[opcode&0x7]
+		op = bitOps[(opcode>>6&0x03)-1] + " " + string(rune(48+(opcode>>3)&0x07)) + sep + operands[opcode&0x7]
 	}
 	return op
 }
diff --git a/dis/z80disasm_test.go b/dis/z80disasm_test.go
index 68ed9bf..9d529b9 100644
--- a/dis/z80disasm_test.go
+++ b/dis/z80disasm_test.go
@@ -129,3 +129,26 @@ func Test_LD_r_IXn(t *testing.T) {
 		t.Errorf("Error disassm LD_r_IXn, result '%s', expected '%s'", res, expected)
 	}
 }
+
+var testBITnH = []byte{0xcb, 0x64, 0xcb, 0xde, 0xcb, 0x95}
+
+func Test_BIT_nn(t *testing.T) {
+	expected := "  0000 BIT 4, H" // JR back
+	setMemory(0x0000, testBITnH)
+	res := disasm.Disassm(0x0000)
+	if res != expected {
+		t.Errorf("Error disassm BIT n,H, result '%s', expected '%s'", res, expected)
+	}
+
+	expected = "  0002 SET 3, (HL)" // JR back
+	res = disasm.Disassm(0x0002)
+	if res != expected {
+		t.Errorf("Error disassm SET n,(HL), result '%s', expected '%s'", res, expected)
+	}
+
+	expected = "  0004 RES 2, L" // JR back
+	res = disasm.Disassm(0x0004)
+	if res != expected {
+		t.Errorf("Error disassm RES n,(HL), result '%s', expected '%s'", res, expected)
+	}
+}