diff --git a/scripts/src/cpu.lua b/scripts/src/cpu.lua
index 77c93b5bb0c..42214efa189 100644
--- a/scripts/src/cpu.lua
+++ b/scripts/src/cpu.lua
@@ -2858,6 +2858,7 @@ end
 --@src/devices/cpu/rw5000/a5500.h,CPUS["RW5000"] = true
 --@src/devices/cpu/rw5000/a5900.h,CPUS["RW5000"] = true
 --@src/devices/cpu/rw5000/b5000.h,CPUS["RW5000"] = true
+--@src/devices/cpu/rw5000/b5000.h,CPUS["RW5000"] = true
 --@src/devices/cpu/rw5000/b6000.h,CPUS["RW5000"] = true
 --@src/devices/cpu/rw5000/b6100.h,CPUS["RW5000"] = true
 --------------------------------------------------
@@ -2869,6 +2870,8 @@ if CPUS["RW5000"] then
 		MAME_DIR .. "src/devices/cpu/rw5000/b5000.cpp",
 		MAME_DIR .. "src/devices/cpu/rw5000/b5000.h",
 		MAME_DIR .. "src/devices/cpu/rw5000/b5000op.cpp",
+		MAME_DIR .. "src/devices/cpu/rw5000/b5500.cpp",
+		MAME_DIR .. "src/devices/cpu/rw5000/b5500.h",
 		MAME_DIR .. "src/devices/cpu/rw5000/b6000.cpp",
 		MAME_DIR .. "src/devices/cpu/rw5000/b6000.h",
 		MAME_DIR .. "src/devices/cpu/rw5000/b6100.cpp",
diff --git a/src/devices/cpu/rw5000/b5500.cpp b/src/devices/cpu/rw5000/b5500.cpp
new file mode 100644
index 00000000000..edf697118c9
--- /dev/null
+++ b/src/devices/cpu/rw5000/b5500.cpp
@@ -0,0 +1,74 @@
+// license:BSD-3-Clause
+// copyright-holders:hap
+/*
+
+  Rockwell B5500 MCU
+
+*/
+
+#include "emu.h"
+#include "b5500.h"
+
+#include "rw5000d.h"
+
+
+DEFINE_DEVICE_TYPE(B5500, b5500_cpu_device, "b5500", "Rockwell B5500")
+
+
+// constructor
+b5500_cpu_device::b5500_cpu_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) :
+	b5000_cpu_device(mconfig, B5500, tag, owner, clock, 10, address_map_constructor(FUNC(b5500_cpu_device::program_768x8), this), 6, address_map_constructor(FUNC(b5500_cpu_device::data_48x4), this))
+{ }
+
+
+// internal memory maps
+void b5500_cpu_device::program_768x8(address_map &map)
+{
+	map(0x000, 0x27f).rom();
+	map(0x380, 0x3ff).rom();
+}
+
+void b5500_cpu_device::data_48x4(address_map &map)
+{
+	map(0x00, 0x0b).ram();
+	map(0x10, 0x1b).ram();
+	map(0x20, 0x2b).ram();
+	map(0x30, 0x3b).ram();
+}
+
+
+// disasm
+std::unique_ptr<util::disasm_interface> b5500_cpu_device::create_disassembler()
+{
+	return std::make_unique<b5500_disassembler>();
+}
+
+
+//-------------------------------------------------
+//  execute
+//-------------------------------------------------
+
+void b5500_cpu_device::execute_one()
+{
+	switch (m_op)
+	{
+		case 0x1c: case 0x1d: case 0x1e: case 0x1f: op_lb(11); break;
+		case 0x38: case 0x39: case 0x3a: case 0x3b: op_tl(); break;
+
+		case 0x0c: op_sc(); break;
+		case 0x0d: op_rsc(); break;
+
+		// rest is same as B5000
+		default: b5000_cpu_device::execute_one(); break;
+	}
+}
+
+bool b5500_cpu_device::op_is_tl(u8 op)
+{
+	return b5000_cpu_device::op_is_tl(op) || ((op & 0xfc) == 0x38);
+}
+
+bool b5500_cpu_device::op_is_lb(u8 op)
+{
+	return b5000_cpu_device::op_is_lb(op) || ((op & 0xfc) == 0x1c);
+}
diff --git a/src/devices/cpu/rw5000/b5500.h b/src/devices/cpu/rw5000/b5500.h
new file mode 100644
index 00000000000..e054d468228
--- /dev/null
+++ b/src/devices/cpu/rw5000/b5500.h
@@ -0,0 +1,41 @@
+// license:BSD-3-Clause
+// copyright-holders:hap
+/*
+
+  Rockwell B5500 MCU
+
+*/
+
+#ifndef MAME_CPU_RW5000_B5500_H
+#define MAME_CPU_RW5000_B5500_H
+
+#pragma once
+
+#include "b5000.h"
+
+
+class b5500_cpu_device : public b5000_cpu_device
+{
+public:
+	b5500_cpu_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock);
+
+protected:
+	// device_disasm_interface overrides
+	virtual std::unique_ptr<util::disasm_interface> create_disassembler() override;
+
+	// device_execute_interface overrides
+	virtual void execute_one() override;
+
+	virtual bool op_is_tl(u8 op) override;
+	virtual bool op_is_lb(u8 op) override;
+	virtual void reset_pc() override { set_pc(0, 0); }
+	virtual u8 sr_page() override { return 15; }
+
+	void program_768x8(address_map &map);
+	void data_48x4(address_map &map);
+};
+
+
+DECLARE_DEVICE_TYPE(B5500, b5500_cpu_device)
+
+#endif // MAME_CPU_RW5000_B5500_H
diff --git a/src/devices/cpu/rw5000/rw5000d.cpp b/src/devices/cpu/rw5000/rw5000d.cpp
index 7d4fbf294c9..a37530b5dbc 100644
--- a/src/devices/cpu/rw5000/rw5000d.cpp
+++ b/src/devices/cpu/rw5000/rw5000d.cpp
@@ -234,6 +234,38 @@ offs_t b5000_disassembler::disassemble(std::ostream &stream, offs_t pc, const da
 }
 
 
+// B5500 disasm (B5000 + LB x,11, SC/RSC moved to make room for more TL)
+
+const u8 b5500_disassembler::b5500_opmap[0x100] =
+{
+/*  0        1        2        3        4        5        6        7        8        9        A        B        C        D        E        F  */
+	em_NOP,  em_TC,   em_TKB,  em_TKBS, em_TDIN, em_TDIN, em_TDIN, em_TDIN, em_TM,   em_TM,   em_TM,   em_TM,   em_SC,   em_RSC,  0,       0,       // 0
+	em_SM,   em_SM,   em_SM,   em_SM,   em_RSM,  em_RSM,  em_RSM,  em_RSM,  em_RET,  em_RET,  em_RET,  em_RET,  em_LB11, em_LB11, em_LB11, em_LB11, // 1
+	em_LB7,  em_LB7,  em_LB7,  em_LB7,  em_LB10, em_LB10, em_LB10, em_LB10, em_LB9,  em_LB9,  em_LB9,  em_LB9,  em_LB8,  em_LB8,  em_LB8,  em_LB8,  // 2
+	em_TL,   em_TL,   em_TL,   em_TL,   em_TL,   em_TL,   em_TL,   em_TL,   em_TL,   em_TL,   em_TL,   em_TL,   em_LB0,  em_LB0,  em_LB0,  em_LB0,  // 3
+
+	em_LAX,  em_LAX,  em_LAX,  em_LAX,  em_LAX,  em_LAX,  em_LAX,  em_LAX,  em_LAX,  em_LAX,  em_LAX,  em_LAX,  em_LAX,  em_LAX,  em_LAX,  em_LAX,  // 4
+	em_LDA,  em_LDA,  em_LDA,  em_LDA,  em_EXCP, em_EXCP, em_EXCP, em_EXCP, em_EXC0, em_EXC0, em_EXC0, em_EXC0, em_EXCM, em_EXCM, em_EXCM, em_EXCM, // 5
+	em_ADX,  em_ADX,  em_ADX,  em_ADX,  em_ADX,  em_ADX,  em_ADX,  em_ADX,  em_ADX,  em_ADX,  em_ADX,  em_ADX,  em_ADX,  em_ADX,  em_ADX,  em_READ, // 6
+	em_ADD,  em_ADD,  em_ADD,  em_ADD,  em_KSEG, 0,       0,       em_ATB,  em_COMP, em_COMP, em_COMP, em_COMP, em_TAM,  em_TAM,  em_TAM,  em_TAM,  // 7
+
+	em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, // 8
+	em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, // 9
+	em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, // A
+	em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, em_TRA0, // B
+
+	em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, // C
+	em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, // D
+	em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, // E
+	em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, em_TRA1, // F
+};
+
+offs_t b5500_disassembler::disassemble(std::ostream &stream, offs_t pc, const data_buffer &opcodes, const data_buffer &params)
+{
+	return common_disasm(b5500_opmap, stream, pc, opcodes, params);
+}
+
+
 // B6000 disasm (B5000 + ATBZ added)
 
 const u8 b6000_disassembler::b6000_opmap[0x100] =
diff --git a/src/devices/cpu/rw5000/rw5000d.h b/src/devices/cpu/rw5000/rw5000d.h
index 45b86f8e2df..889c84853db 100644
--- a/src/devices/cpu/rw5000/rw5000d.h
+++ b/src/devices/cpu/rw5000/rw5000d.h
@@ -85,6 +85,18 @@ private:
 	static const u8 b5000_opmap[0x100];
 };
 
+class b5500_disassembler : public rw5000_common_disassembler
+{
+public:
+	b5500_disassembler() = default;
+	virtual ~b5500_disassembler() = default;
+
+	virtual offs_t disassemble(std::ostream &stream, offs_t pc, const data_buffer &opcodes, const data_buffer &params) override;
+
+private:
+	static const u8 b5500_opmap[0x100];
+};
+
 class b6000_disassembler : public rw5000_common_disassembler
 {
 public:
diff --git a/src/mame/drivers/hh_rw5000.cpp b/src/mame/drivers/hh_rw5000.cpp
index d781ed5bf4c..dc6de9a4c77 100644
--- a/src/mame/drivers/hh_rw5000.cpp
+++ b/src/mame/drivers/hh_rw5000.cpp
@@ -19,6 +19,7 @@ ROM source notes when dumped from another model, but confident it's the same:
 #include "cpu/rw5000/a5500.h"
 #include "cpu/rw5000/a5900.h"
 #include "cpu/rw5000/b5000.h"
+#include "cpu/rw5000/b5500.h"
 #include "cpu/rw5000/b6000.h"
 #include "cpu/rw5000/b6100.h"
 #include "video/pwm.h"
diff --git a/src/tools/unidasm.cpp b/src/tools/unidasm.cpp
index e58e5ed22f2..aa08ba7d7ca 100644
--- a/src/tools/unidasm.cpp
+++ b/src/tools/unidasm.cpp
@@ -394,6 +394,7 @@ static const dasm_table_entry dasm_table[] =
 	{ "axc51core",       le,  0, []() -> util::disasm_interface * { return new axc51core_disassembler; } },
 	{ "axc208",          le,  0, []() -> util::disasm_interface * { return new ax208_disassembler; } },
 	{ "b5000",           le,  0, []() -> util::disasm_interface * { return new b5000_disassembler; } },
+	{ "b5500",           le,  0, []() -> util::disasm_interface * { return new b5500_disassembler; } },
 	{ "b6000",           le,  0, []() -> util::disasm_interface * { return new b6000_disassembler; } },
 	{ "b6100",           le,  0, []() -> util::disasm_interface * { return new b6100_disassembler; } },
 	{ "capricorn",       le,  0, []() -> util::disasm_interface * { return new capricorn_disassembler; } },