diff --git a/CMakeLists.txt b/CMakeLists.txt
index 23931f0..312f969 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -17,6 +17,7 @@ if(WIN32)
     add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
     add_compile_definitions(NOMINMAX)
 endif()
+add_compile_options(-fno-operator-names)
 
 set(CAPSTONE_ARCHITECTURE_DEFAULT OFF)
 set(CAPSTONE_PPC_SUPPORT ON)
diff --git a/core/broadway.cpp b/core/broadway.cpp
index 6d198aa..e6c4d6d 100644
--- a/core/broadway.cpp
+++ b/core/broadway.cpp
@@ -17,27 +17,66 @@ void broadway::set_pc(ircolib::u32 value) { pc = value; }
 
 void broadway::run(mem &mem) {
     for (int i = 0; i < 12150000; i++) {
+        // std::println("pc: 0x{:08X}", pc);
         execute(fetch(mem), mem);
     }
 }
 
 ircolib::u32 broadway::fetch(mem &mem) {
-    ircolib::u32 val = mem.read32(pc);
+    ircolib::u32 val = mem.read32(pc)
+                       .and_then([&](ircolib::u32 val) { return std::expected<ircolib::u32, std::string>(val); })
+                       .or_else([&](std::string e) {
+                           ircolib::panic("broadway read failed. Reason {} (pc: 0x{:08X})", e, pc);
+                           return std::expected<ircolib::u32, std::string>();
+                       })
+                       .value();
     pc += 4;
 
     return val;
 }
 
+void broadway::decode_special3(ircolib::u32 instr, mem &mem) {
+    auto secondary = utils::secondary(instr);
+    switch (secondary) {
+    case 38:
+        mtfsb1(instr);
+        break;
+    case 711:
+        mtfsf(instr);
+        break;
+    default:
+        ircolib::panic("broadway unknown special3 {} (0x{:04X}) (pc 0x{:08X})", secondary, secondary, pc - 4);
+    }
+}
+
 void broadway::decode_special2(ircolib::u32 instr, mem &mem) {
     auto secondary = utils::secondary(instr);
     switch (secondary) {
+    case 0x000:
+        cmp(instr);
+        break;
+    case 0x020:
+        cmpl(instr);
+        break;
+    case 0x028:
+        subf(instr);
+        break;
+    case 0x053:
+        mfmsr(instr);
+        break;
     case 0x0D2:
         ircolib::warn("broadway TODO mtsr (pc 0x{:08X})", pc - 4);
         break;
+    case 0x1BC:
+        or (instr);
+        break;
     case 0x153:
     case 0x1D3:
         mftspr(ircolib::is_bit_set<ircolib::u32, 7>(secondary), instr);
         break;
+    case 0x1DC:
+        nand(instr);
+        break;
     case 0x10A:
         add(instr);
         break;
@@ -66,6 +105,9 @@ void broadway::decode_special1(ircolib::u32 instr, mem &mem) {
 
 void broadway::execute(ircolib::u32 instr, mem &mem) {
     switch (utils::primary(instr)) {
+    case 10:
+        cmpli(instr);
+        break;
     case 11:
         cmpi(instr);
         break;
@@ -111,12 +153,18 @@ void broadway::execute(ircolib::u32 instr, mem &mem) {
     case 37:
         stwu(instr, mem);
         break;
+    case 39:
+        stbu(instr, mem);
+        break;
     case 44:
         sth(instr, mem);
         break;
     case 50:
         lfd(instr, mem);
         break;
+    case 63:
+        decode_special3(instr, mem);
+        break;
     default:
         std::println("broadway::execute unimplemented instruction 0x{:08X} / 0b{:032b}", instr, instr);
         std::println("disassembly:");
diff --git a/core/broadway.hpp b/core/broadway.hpp
index c700a9c..3fe2e41 100644
--- a/core/broadway.hpp
+++ b/core/broadway.hpp
@@ -17,7 +17,7 @@ struct broadway {
     void execute(ircolib::u32, mem &);
 
     bool disasm_available = true;
-    ircolib::u32 pc = 0, lr = 0, ctr = 0, cr = 0, srr0;
+    ircolib::u32 pc = 0, lr = 0, ctr = 0, cr = 0, srr0 = 0, fpscr = 0, msr = 0;
     union {
         struct {
             unsigned bytecount : 7;
@@ -43,7 +43,13 @@ struct broadway {
 
     std::array<ircolib::u32, 16> ibat, dbat;
     std::array<ircolib::u32, 32> gpr{};
-    std::array<double, 32> fpr{};
+
+    struct Fgr {
+        ircolib::u64 ps0, ps1;
+    };
+
+    std::array<Fgr, 32> fgrs{};
+
     // ircolib::u32 const_gpr_lookup{};
     csh capstone;
     // Xbyak::CodeGenerator code;
@@ -51,6 +57,7 @@ struct broadway {
     // instructions
     void decode_special1(ircolib::u32, mem &);
     void decode_special2(ircolib::u32, mem &);
+    void decode_special3(ircolib::u32, mem &);
 
     void branch(bool, bool, ircolib::u32);
     bool test_cond_and_ctr(ircolib::u32);
@@ -66,14 +73,25 @@ struct broadway {
     void mftspr(bool, ircolib::u32);
     void stw(ircolib::u32, mem &);
     void stwu(ircolib::u32, mem &);
+    void stbu(ircolib::u32, mem &);
     void sth(ircolib::u32, mem &);
     void lwz(ircolib::u32, mem &);
     void lfd(ircolib::u32, mem &);
     void bclrx(ircolib::u32);
     void cmpi(ircolib::u32);
+    void cmpli(ircolib::u32);
+    void cmp(ircolib::u32);
+    void cmpl(ircolib::u32);
     void rlwinm(ircolib::u32);
     void lwzu(ircolib::u32, mem &);
     void rfi(ircolib::u32);
+    void mtfsf(ircolib::u32);
+    void mtfsb1(ircolib::u32);
+    void mtfsb0(ircolib::u32);
+    void mfmsr(ircolib::u32);
+    void nand(ircolib::u32);
+    void subf(ircolib::u32);
+    void or (ircolib::u32);
 
     inline void cr0_update(bool condition, ircolib::s32 result) {
         if (condition) {
@@ -84,5 +102,12 @@ struct broadway {
             set_cr((b0 << 3) | (b1 << 2) | (b2 << 1) | (b3 << 0), 0);
         }
     }
+
+    inline void cr1_update(bool condition) {
+        if (condition) {
+            const ircolib::u8 field = (fpscr >> 28) & 0xf;
+            set_cr(field, 1);
+        }
+    }
 };
 } // namespace weee::core
diff --git a/core/broadway/instructions.cpp b/core/broadway/instructions.cpp
index ba4f3cd..1f7feda 100644
--- a/core/broadway/instructions.cpp
+++ b/core/broadway/instructions.cpp
@@ -1,5 +1,5 @@
-#include <broadway/utils.hpp>
 #include "ircolib/log.hpp"
+#include <broadway/utils.hpp>
 #include <mem.hpp>
 
 namespace weee::core {
@@ -49,6 +49,7 @@ void broadway::bx(ircolib::u32 instr) {
 bool broadway::test_cond_and_ctr(ircolib::u32 instr) {
     const ircolib::u8 bo = (instr >> 21) & 0x1f;
     const ircolib::u8 bi = (instr >> 16) & 0x1f;
+
     const bool ctr_ok = ircolib::is_bit_set(bo, 2) || ((--ctr == 0) == (ircolib::is_bit_set(bo, 1)));
     const bool cond_ok = ircolib::is_bit_set(bo, 4) || (get_cr_bit(0, bi) == ircolib::is_bit_set(bo, 3));
 
@@ -132,7 +133,8 @@ void broadway::mftspr(bool dir, ircolib::u32 instr) {
         move_to_or_from_spr(dbat[BAT_UPPER_OFFSET + 3]);
         break;
     default:
-        ircolib::warn("broadway::m{}spr with unimplemented spr field of value 0b{:010b} (0x{:04X}) (pc 0x{:08X})",
+        ircolib::warn("broadway::m{}spr with unimplemented spr field of value "
+                      "0b{:010b} (0x{:04X}) (pc 0x{:08X})",
                       dir ? 't' : 'f', spr_field, spr_field, pc - 4);
     }
 }
@@ -142,7 +144,26 @@ void broadway::stwu(ircolib::u32 instr, mem &mem) {
         ircolib::panic("broadway::stwu with ra == 0");
 
     const ircolib::u32 EA = ircolib::s32(gpr[utils::RA(instr)]) + utils::SIMM(instr);
-    mem.write32(EA, gpr[utils::RS(instr)]);
+    auto _ = mem.write32(EA, gpr[utils::RS(instr)])
+             .and_then([&] { return std::expected<void, std::string>(); })
+             .or_else([&](std::string e) {
+                 ircolib::panic("broadway write failed. Reason: {} (pc: 0x{:08X})", e, pc - 4);
+                 return std::expected<void, std::string>();
+             });
+    gpr[utils::RA(instr)] = EA;
+}
+
+void broadway::stbu(ircolib::u32 instr, mem &mem) {
+    if (utils::RA(instr) == 0)
+        ircolib::panic("broadway::stbu with ra == 0");
+
+    const ircolib::u32 EA = ircolib::s32(gpr[utils::RA(instr)]) + utils::SIMM(instr);
+    auto _ = mem.write8(EA, gpr[utils::RS(instr)])
+             .and_then([&] { return std::expected<void, std::string>(); })
+             .or_else([&](std::string e) {
+                 ircolib::panic("broadway write failed. Reason: {} (pc: 0x{:08X})", e, pc - 4);
+                 return std::expected<void, std::string>();
+             });
     gpr[utils::RA(instr)] = EA;
 }
 
@@ -152,7 +173,12 @@ void broadway::stw(ircolib::u32 instr, mem &mem) {
         b = 0;
 
     const ircolib::u32 EA = b + utils::SIMM(instr);
-    mem.write32(EA, gpr[utils::RS(instr)]);
+    auto _ = mem.write32(EA, gpr[utils::RS(instr)])
+             .and_then([&] { return std::expected<void, std::string>(); })
+             .or_else([&](std::string e) {
+                 ircolib::panic("broadway write failed. Reason: {} (pc: 0x{:08X})", e, pc - 4);
+                 return std::expected<void, std::string>();
+             });
 }
 
 void broadway::sth(ircolib::u32 instr, mem &mem) {
@@ -163,7 +189,12 @@ void broadway::sth(ircolib::u32 instr, mem &mem) {
     const ircolib::s32 d = utils::SIMM(instr);
     const ircolib::u32 EA = b + d;
 
-    mem.write16(EA, ircolib::u16(gpr[utils::RS(instr)]));
+    auto _ = mem.write16(EA, ircolib::u16(gpr[utils::RS(instr)]))
+             .and_then([&] { return std::expected<void, std::string>(); })
+             .or_else([&](std::string e) {
+                 ircolib::panic("broadway write failed. Reason: {} (pc: 0x{:08X})", e, pc - 4);
+                 return std::expected<void, std::string>();
+             });
 }
 
 void broadway::lwz(ircolib::u32 instr, mem &mem) {
@@ -172,7 +203,14 @@ void broadway::lwz(ircolib::u32 instr, mem &mem) {
         b = 0;
 
     ircolib::u32 ea = ircolib::s32(b) + utils::SIMM(instr);
-    gpr[utils::RD(instr)] = mem.read32(ea);
+
+    gpr[utils::RD(instr)] = mem.read32(ea)
+                            .and_then([&](ircolib::u32 val) { return std::expected<ircolib::u32, std::string>(val); })
+                            .or_else([&](std::string e) {
+                                ircolib::panic("broadway read failed. Reason {} (pc: 0x{:08X})", e, pc - 4);
+                                return std::expected<ircolib::u32, std::string>();
+                            })
+                            .value();
 }
 
 void broadway::lfd(ircolib::u32 instr, mem &mem) {
@@ -182,9 +220,15 @@ void broadway::lfd(ircolib::u32 instr, mem &mem) {
 
     ircolib::u32 ea = ircolib::s32(b) + utils::SIMM(instr);
     double val;
-    ircolib::u64 read = mem.read64(ea);
+    ircolib::u64 read = mem.read64(ea)
+                        .and_then([&](ircolib::u64 val) { return std::expected<ircolib::u64, std::string>(val); })
+                        .or_else([&](std::string e) {
+                            ircolib::panic("broadway read failed. Reason {} (pc: 0x{:08X})", e, pc - 4);
+                            return std::expected<ircolib::u64, std::string>();
+                        })
+                        .value();
     memcpy(&val, &read, 8);
-    fpr[utils::RD(instr)] = val;
+    fgrs[utils::RD(instr)].ps0 = val;
 }
 
 void broadway::bclrx(ircolib::u32 instr) {
@@ -211,6 +255,51 @@ void broadway::cmpi(ircolib::u32 instr) {
     set_cr(result, utils::crfD(instr));
 }
 
+void broadway::cmpli(ircolib::u32 instr) {
+    const ircolib::u32 a = gpr[utils::RA(instr)];
+    const ircolib::u32 uimm = utils::UIMM(instr);
+    ircolib::u8 c;
+    if (a < uimm)
+        c = 0b001;
+    else if (a > uimm)
+        c = 0b010;
+    else
+        c = 0b100;
+
+    const ircolib::u8 result = (xer.so << 3) | c;
+    set_cr(result, utils::crfD(instr));
+}
+
+void broadway::cmp(ircolib::u32 instr) {
+    const ircolib::s32 a = gpr[utils::RA(instr)];
+    const ircolib::s32 b = gpr[utils::RB(instr)];
+    ircolib::u8 c;
+    if (a < b)
+        c = 0b001;
+    else if (a > b)
+        c = 0b010;
+    else
+        c = 0b100;
+
+    const ircolib::u8 result = (xer.so << 3) | c;
+    set_cr(result, utils::crfD(instr));
+}
+
+void broadway::cmpl(ircolib::u32 instr) {
+    const ircolib::u32 a = gpr[utils::RA(instr)];
+    const ircolib::u32 b = gpr[utils::RB(instr)];
+    ircolib::u8 c;
+    if (a < b)
+        c = 0b001;
+    else if (a > b)
+        c = 0b010;
+    else
+        c = 0b100;
+
+    const ircolib::u8 result = (xer.so << 3) | c;
+    set_cr(result, utils::crfD(instr));
+}
+
 void broadway::rlwinm(ircolib::u32 instr) {
     const ircolib::u8 sh = (instr >> 11) & 0x1f;
     ircolib::u32 r = std::rotl(gpr[utils::RS(instr)], sh);
@@ -226,7 +315,13 @@ void broadway::lwzu(ircolib::u32 instr, mem &mem) {
         ircolib::panic("broadway::lwzu with ra == 0");
 
     const ircolib::u32 EA = ircolib::s32(gpr[utils::RA(instr)]) + utils::SIMM(instr);
-    gpr[utils::RD(instr)] = mem.read32(EA);
+    gpr[utils::RD(instr)] = mem.read32(EA)
+                            .and_then([&](ircolib::u32 val) { return std::expected<ircolib::u32, std::string>(val); })
+                            .or_else([&](std::string e) {
+                                ircolib::panic("broadway read failed. Reason {} (pc: 0x{:08X})", e, pc - 4);
+                                return std::expected<ircolib::u32, std::string>();
+                            })
+                            .value();
     gpr[utils::RA(instr)] = EA;
 }
 
@@ -237,4 +332,50 @@ void broadway::andi(ircolib::u32 instr) {
     gpr[utils::RA(instr)] = result;
     cr0_update(true, result);
 }
+
+void broadway::mtfsf(ircolib::u32 instr) {
+    const ircolib::u8 fm = (instr >> 17) & 0xff;
+    ircolib::u8 mask = 0;
+    for (int i = 0; i < 8; i++) {
+        if (ircolib::is_bit_set(fm, i)) {
+            mask |= 0xf << (i * 4);
+        }
+    }
+
+    ircolib::u32 frb = fgrs[utils::RB(instr)].ps0;
+    fpscr = (fpscr & ~mask) | (frb & mask);
+    cr1_update(instr & 1);
+}
+
+void broadway::mtfsb0(ircolib::u32 instr) {
+    ircolib::u32 mask = ~(1 << utils::RD(instr));
+
+    fpscr = fpscr & mask;
+    cr1_update(instr & 1);
+}
+
+void broadway::mtfsb1(ircolib::u32 instr) {
+    ircolib::u32 bit = 1 << utils::RD(instr);
+    ircolib::u32 mask = ~bit;
+
+    fpscr = (fpscr & mask) | bit;
+    cr1_update(instr & 1);
+}
+
+void broadway::mfmsr(ircolib::u32 instr) { gpr[utils::RS(instr)] = msr; }
+
+void broadway::nand(ircolib::u32 instr) {
+    gpr[utils::RA(instr)] = ~(gpr[utils::RS(instr)] & gpr[utils::RB(instr)]);
+    cr0_update(instr & 1, gpr[utils::RA(instr)]);
+}
+
+void broadway::subf(ircolib::u32 instr) {
+    gpr[utils::RD(instr)] = ~(gpr[utils::RA(instr)] + gpr[utils::RB(instr)] + 1);
+    cr0_update(instr & 1, gpr[utils::RD(instr)]);
+}
+
+void broadway:: or (ircolib::u32 instr) {
+    gpr[utils::RA(instr)] = gpr[utils::RS(instr)] & gpr[utils::RB(instr)];
+    cr0_update(instr & 1, gpr[utils::RA(instr)]);
+}
 } // namespace weee::core
diff --git a/core/mem.cpp b/core/mem.cpp
index 8e38fc1..6adb030 100644
--- a/core/mem.cpp
+++ b/core/mem.cpp
@@ -7,6 +7,9 @@ namespace weee::core {
 mem::mem() : vi(*this) {
     mem1.resize(24_mib);
     std::fill(mem1.begin(), mem1.end(), 0);
+
+    register_read8_handler(0x00000000, 0x017fffff, [&](ircolib::u32 addr) { return mem1[addr]; });
+
     register_read16_handler(0x00000000, 0x017fffff,
                             [&](ircolib::u32 addr) { return ircolib::read_access<ircolib::u16>(mem1, addr); });
 
@@ -16,6 +19,8 @@ mem::mem() : vi(*this) {
     register_read64_handler(0x00000000, 0x017fffff,
                             [&](ircolib::u32 addr) { return ircolib::read_access<ircolib::u64>(mem1, addr); });
 
+    register_write8_handler(0x00000000, 0x017fffff, [&](ircolib::u32 addr, ircolib::u8 value) { mem1[addr] = value; });
+
     register_write16_handler(0x00000000, 0x017fffff, [&](ircolib::u32 addr, ircolib::u16 value) {
         ircolib::write_access<ircolib::u16>(mem1, addr, value);
     });
@@ -52,7 +57,7 @@ void mem::set(const ircolib::u8 val, const ircolib::u32 size, const ircolib::u32
     memset(&mem1[offset], val, size);
 }
 
-ircolib::u8 mem::read8(ircolib::u32 addr) {
+std::expected<ircolib::u8, std::string> mem::read8(ircolib::u32 addr) {
     addr &= 0x0FFFFFFF;
     for (const auto &handler : read8_handlers) {
         if (ircolib::is_inside_range(addr, handler.start, handler.end)) {
@@ -60,11 +65,10 @@ ircolib::u8 mem::read8(ircolib::u32 addr) {
         }
     }
 
-    ircolib::panic("mem::read8 unimplemented addr 0x{:08X}", addr);
-    return 0;
+    return std::unexpected(std::format("mem::read8 unimplemented addr 0x{:08X}", addr));
 }
 
-ircolib::u16 mem::read16(ircolib::u32 addr) {
+std::expected<ircolib::u16, std::string> mem::read16(ircolib::u32 addr) {
     addr &= 0x0FFFFFFF;
     for (const auto &handler : read16_handlers) {
         if (ircolib::is_inside_range(addr, handler.start, handler.end)) {
@@ -72,11 +76,10 @@ ircolib::u16 mem::read16(ircolib::u32 addr) {
         }
     }
 
-    ircolib::panic("mem::read16 unimplemented addr 0x{:08X}", addr);
-    return 0;
+    return std::unexpected(std::format("mem::read16 unimplemented addr 0x{:08X}", addr));
 }
 
-ircolib::u32 mem::read32(ircolib::u32 addr) {
+std::expected<ircolib::u32, std::string> mem::read32(ircolib::u32 addr) {
     addr &= 0x0FFFFFFF;
     for (const auto &handler : read32_handlers) {
         if (ircolib::is_inside_range(addr, handler.start, handler.end)) {
@@ -84,11 +87,10 @@ ircolib::u32 mem::read32(ircolib::u32 addr) {
         }
     }
 
-    ircolib::panic("mem::read32 unimplemented addr 0x{:08X}", addr);
-    return 0;
+    return std::unexpected(std::format("mem::read32 unimplemented addr 0x{:08X}", addr));
 }
 
-ircolib::u64 mem::read64(ircolib::u32 addr) {
+std::expected<ircolib::u64, std::string> mem::read64(ircolib::u32 addr) {
     addr &= 0x0FFFFFFF;
     for (const auto &handler : read64_handlers) {
         if (ircolib::is_inside_range(addr, handler.start, handler.end)) {
@@ -96,51 +98,54 @@ ircolib::u64 mem::read64(ircolib::u32 addr) {
         }
     }
 
-    ircolib::panic("mem::read64 unimplemented addr 0x{:08X}", addr);
-    return 0;
+    return std::unexpected(std::format("mem::read64 unimplemented addr 0x{:08X}", addr));
 }
 
-void mem::write8(ircolib::u32 addr, ircolib::u8 value) {
+std::expected<void, std::string> mem::write8(ircolib::u32 addr, ircolib::u8 value) {
     addr &= 0x0FFFFFFF;
     for (const auto &handler : write8_handlers) {
         if (ircolib::is_inside_range(addr, handler.start, handler.end)) {
-            return handler.func(addr - handler.start, value);
+            handler.func(addr - handler.start, value);
+            return std::expected<void, std::string>();
         }
     }
 
-    ircolib::panic("mem::write8 unimplemented addr 0x{:08X} = 0x{:02X}", addr, value);
+    return std::unexpected(std::format("mem::write8 unimplemented addr 0x{:08X} = 0x{:02X}", addr, value));
 }
 
-void mem::write16(ircolib::u32 addr, ircolib::u16 value) {
+std::expected<void, std::string> mem::write16(ircolib::u32 addr, ircolib::u16 value) {
     addr &= 0x0FFFFFFF;
     for (const auto &handler : write16_handlers) {
         if (ircolib::is_inside_range(addr, handler.start, handler.end)) {
-            return handler.func(addr - handler.start, value);
+            handler.func(addr - handler.start, value);
+            return std::expected<void, std::string>();
         }
     }
 
-    ircolib::panic("mem::write16 unimplemented addr 0x{:08X} = 0x{:04X}", addr, value);
+    return std::unexpected(std::format("mem::write16 unimplemented addr 0x{:08X} = 0x{:04X}", addr, value));
 }
 
-void mem::write32(ircolib::u32 addr, ircolib::u32 value) {
+std::expected<void, std::string> mem::write32(ircolib::u32 addr, ircolib::u32 value) {
     addr &= 0x0FFFFFFF;
     for (const auto &handler : write32_handlers) {
         if (ircolib::is_inside_range(addr, handler.start, handler.end)) {
-            return handler.func(addr - handler.start, value);
+            handler.func(addr - handler.start, value);
+            return std::expected<void, std::string>();
         }
     }
 
-    ircolib::panic("mem::write32 unimplemented addr 0x{:08X} = 0x{:08X}", addr, value);
+    return std::unexpected(std::format("mem::write32 unimplemented addr 0x{:08X} = 0x{:08X}", addr, value));
 }
 
-void mem::write64(ircolib::u32 addr, ircolib::u64 value) {
+std::expected<void, std::string> mem::write64(ircolib::u32 addr, ircolib::u64 value) {
     addr &= 0x0FFFFFFF;
     for (const auto &handler : write64_handlers) {
         if (ircolib::is_inside_range(addr, handler.start, handler.end)) {
-            return handler.func(addr - handler.start, value);
+            handler.func(addr - handler.start, value);
+            return std::expected<void, std::string>();
         }
     }
 
-    ircolib::panic("mem::write64 unimplemented addr 0x{:08X} = 0x{:016X}", addr, value);
+    return std::unexpected(std::format("mem::write64 unimplemented addr 0x{:08X} = 0x{:016X}", addr, value));
 }
 } // namespace weee::core
diff --git a/core/mem.hpp b/core/mem.hpp
index b0aae3f..a436069 100644
--- a/core/mem.hpp
+++ b/core/mem.hpp
@@ -1,8 +1,10 @@
 #pragma once
+#include <string>
 #include <vector>
 #include <ircolib/types.hpp>
 #include <broadway/mmio/vi.hpp>
 #include <functional>
+#include <expected>
 
 namespace weee::core {
 template <typename T>
@@ -53,14 +55,14 @@ struct mem {
         write64_handlers.push_back({std::move(func), start, end});
     }
 
-    ircolib::u8 read8(ircolib::u32);
-    ircolib::u16 read16(ircolib::u32);
-    ircolib::u32 read32(ircolib::u32);
-    ircolib::u64 read64(ircolib::u32);
-    void write8(ircolib::u32, ircolib::u8);
-    void write16(ircolib::u32, ircolib::u16);
-    void write32(ircolib::u32, ircolib::u32);
-    void write64(ircolib::u32, ircolib::u64);
+    std::expected<ircolib::u8, std::string> read8(ircolib::u32);
+    std::expected<ircolib::u16, std::string> read16(ircolib::u32);
+    std::expected<ircolib::u32, std::string> read32(ircolib::u32);
+    std::expected<ircolib::u64, std::string> read64(ircolib::u32);
+    std::expected<void, std::string> write8(ircolib::u32, ircolib::u8);
+    std::expected<void, std::string> write16(ircolib::u32, ircolib::u16);
+    std::expected<void, std::string> write32(ircolib::u32, ircolib::u32);
+    std::expected<void, std::string> write64(ircolib::u32, ircolib::u64);
 
     void copy(std::vector<ircolib::u8> &src, const ircolib::u32 offset);
     void copy(ircolib::u8 *src, const ircolib::u32 size, const ircolib::u32 offset);