diff --git a/src/assembler.cpp b/src/assembler.cpp
index 5120a1c..36c2341 100644
--- a/src/assembler.cpp
+++ b/src/assembler.cpp
@@ -158,6 +158,7 @@ auto Assembler::assemble_file()
             if (line->labels) {
                 define_labels(*line->labels);
             }
+            assemble_line(*line);
 
             lines.push_back(std::move(line));
         }
@@ -181,7 +182,7 @@ void Assembler::define_labels(const std::vector<Label>& labels)
 {
     for (const auto& label : labels) {
         if (label.is_local) {
-            m_sublabels[label_ident(label)] = m_builder.ip();
+            m_syms[label_ident(label)] = m_builder.ip();
         } else {
             m_superlabel = label.ident;
             m_syms[std::string(label.ident)] = m_builder.ip();
@@ -325,7 +326,7 @@ void Assembler::assemble_line(const Line& line)
             auto op1 = eval_operand(*line.args[0]);
             auto op2 = eval_operand(*line.args[1]);
 
-            if (not op1 or op2)
+            if (not op1 or not op2)
                 return;
 
             if (not op1->is_reg())
@@ -345,7 +346,7 @@ void Assembler::assemble_line(const Line& line)
             auto dst = eval_operand(*line.args[0]);
             auto src = eval_operand(*line.args[1]);
 
-            if (not dst or src)
+            if (not dst or not src)
                 return;
 
             auto dst_ty = dst->ty;
@@ -641,7 +642,7 @@ auto Assembler::eval_operand_mem(const Expr& expr)
         }
         case Expr::Ty::Reg:
             return std::make_unique<EO>(
-                expr.loc, EOT::MemWordReg, expr.as_reg());
+                expr.loc, EOT::MemWordReg, EO::RegImmPair { expr.as_reg(), 0 });
         case Expr::Ty::Str:
         case Expr::Ty::Mem:
         case Expr::Ty::MemByte:
@@ -716,14 +717,12 @@ auto Assembler::eval_operand_to_imm(const Expr& expr)
         case Expr::Ty::Ident: {
             auto ident = std::string(expr.as_ident());
             if (!m_syms.contains(ident)) {
-                if (m_second_pass) {
-                    error(expr.loc,
-                        std::format(
-                            "symbol \"{}\" not defined", expr.as_ident()));
-                    return nullptr;
-                } else {
+                if (not m_second_pass)
                     return std::make_unique<EO>(loc, EOT::Imm, uint16_t { 0 });
-                }
+
+                error(expr.loc,
+                    std::format("symbol \"{}\" not defined", expr.as_ident()));
+                return nullptr;
             }
 
             auto value = m_syms[ident];
@@ -731,18 +730,16 @@ auto Assembler::eval_operand_to_imm(const Expr& expr)
         }
         case Expr::Ty::SubLabel: {
             auto ident = sublabel_ident(expr.as_ident());
-            if (!m_sublabels.contains(ident)) {
-                if (m_second_pass) {
-                    error(expr.loc,
-                        std::format(
-                            "symbol \"{}\" not defined", expr.as_ident()));
-                    return nullptr;
-                } else {
+            if (!m_syms.contains(ident)) {
+                if (not m_second_pass)
                     return std::make_unique<EO>(loc, EOT::Imm, uint16_t { 0 });
-                }
+
+                error(expr.loc,
+                    std::format("symbol \"{}\" not defined", expr.as_ident()));
+                return nullptr;
             }
 
-            auto value = m_sublabels[ident];
+            auto value = m_syms[ident];
             return std::make_unique<EO>(loc, EOT::Imm, value);
         }
         case Expr::Ty::Reg:
diff --git a/src/assembler.hpp b/src/assembler.hpp
index 8773800..31d95f1 100644
--- a/src/assembler.hpp
+++ b/src/assembler.hpp
@@ -242,7 +242,6 @@ namespace asmer {
         Builder m_builder;
         std::unordered_map<std::string, uint16_t> m_syms {};
         std::string m_superlabel {};
-        std::unordered_map<std::string, uint16_t> m_sublabels {};
         bool m_second_pass = false;
         bool m_failed = false;
     };
diff --git a/src/builder.cpp b/src/builder.cpp
index c324ca8..bf7ba69 100644
--- a/src/builder.cpp
+++ b/src/builder.cpp
@@ -68,20 +68,30 @@ private:
 
 }
 
+#define LOG_F                                                                  \
+    {                                                                          \
+        std::println("assembling {} at {}", __func__, this->m_ip);             \
+    }
+
+#define LOG
+
 void Builder::nop()
 {
+    LOG;
     auto i = InsBuilder(Op::Nop);
     i.build(*this);
 }
 
 void Builder::hlt()
 {
+    LOG;
     auto i = InsBuilder(Op::Hlt);
     i.build(*this);
 }
 
 void Builder::jmp_reg(Reg op1)
 {
+    LOG;
     auto i = InsBuilder(Op::Jmp);
     i.op1_reg(op1);
     i.build(*this);
@@ -89,6 +99,7 @@ void Builder::jmp_reg(Reg op1)
 
 void Builder::jmp_imm(uint16_t op1)
 {
+    LOG;
     auto i = InsBuilder(Op::Jmp);
     i.imm(op1);
     i.build(*this);
@@ -96,6 +107,7 @@ void Builder::jmp_imm(uint16_t op1)
 
 void Builder::jnz_reg(Reg op1, Reg op2)
 {
+    LOG;
     auto i = InsBuilder(Op::Jnz);
     i.op1_reg(op1);
     i.op2_reg(op2);
@@ -104,6 +116,7 @@ void Builder::jnz_reg(Reg op1, Reg op2)
 
 void Builder::jnz_imm(Reg op1, uint16_t op2)
 {
+    LOG;
     auto i = InsBuilder(Op::Jnz);
     i.op1_reg(op1);
     i.imm(op2);
@@ -112,6 +125,7 @@ void Builder::jnz_imm(Reg op1, uint16_t op2)
 
 void Builder::mov_reg(Reg dst, Reg src)
 {
+    LOG;
     auto i = InsBuilder(Op::Mov);
     i.reg(dst, 12, 0b1111);
     i.reg(src, 7, 0b1111);
@@ -120,6 +134,7 @@ void Builder::mov_reg(Reg dst, Reg src)
 
 void Builder::mov_imm(Reg dst, uint16_t imm)
 {
+    LOG;
     auto i = InsBuilder(Op::Mov);
     i.reg(dst, 12, 0b1111);
     i.imm(imm);
@@ -128,6 +143,7 @@ void Builder::mov_imm(Reg dst, uint16_t imm)
 
 void Builder::load_word_reg(Reg dst, Reg addr, uint16_t offset)
 {
+    LOG;
     auto i = InsBuilder(Op::LoadWord);
     i.dst_reg(dst);
     i.op1_reg(addr);
@@ -137,6 +153,7 @@ void Builder::load_word_reg(Reg dst, Reg addr, uint16_t offset)
 
 void Builder::load_word_imm(Reg dst, uint16_t addr)
 {
+    LOG;
     auto i = InsBuilder(Op::LoadWord);
     i.dst_reg(dst);
     i.imm(addr);
@@ -145,6 +162,7 @@ void Builder::load_word_imm(Reg dst, uint16_t addr)
 
 void Builder::store_word_reg(Reg dst, uint16_t offset, Reg op2)
 {
+    LOG;
     auto i = InsBuilder(Op::StoreWord);
     i.dst_reg(dst);
     i.imm_without_flag(offset);
@@ -154,6 +172,7 @@ void Builder::store_word_reg(Reg dst, uint16_t offset, Reg op2)
 
 void Builder::store_word_imm(uint16_t dst, Reg op2)
 {
+    LOG;
     auto i = InsBuilder(Op::StoreWord);
     i.imm(dst);
     i.op2_reg(op2);
@@ -162,6 +181,7 @@ void Builder::store_word_imm(uint16_t dst, Reg op2)
 
 void Builder::load_byte_reg(Reg dst, Reg addr, uint16_t offset)
 {
+    LOG;
     auto i = InsBuilder(Op::LoadByte);
     i.dst_reg(dst);
     i.op1_reg(addr);
@@ -171,6 +191,7 @@ void Builder::load_byte_reg(Reg dst, Reg addr, uint16_t offset)
 
 void Builder::load_byte_imm(Reg dst, uint16_t addr)
 {
+    LOG;
     auto i = InsBuilder(Op::LoadByte);
     i.dst_reg(dst);
     i.imm(addr);
@@ -179,6 +200,7 @@ void Builder::load_byte_imm(Reg dst, uint16_t addr)
 
 void Builder::store_byte_reg(Reg dst, uint16_t offset, Reg op2)
 {
+    LOG;
     auto i = InsBuilder(Op::StoreByte);
     i.dst_reg(dst);
     i.imm_without_flag(offset);
@@ -188,6 +210,7 @@ void Builder::store_byte_reg(Reg dst, uint16_t offset, Reg op2)
 
 void Builder::store_byte_imm(uint16_t dst, Reg op2)
 {
+    LOG;
     auto i = InsBuilder(Op::StoreByte);
     i.imm(dst);
     i.op2_reg(op2);
@@ -196,6 +219,7 @@ void Builder::store_byte_imm(uint16_t dst, Reg op2)
 
 void Builder::cmp_reg(Reg op1, Reg op2)
 {
+    LOG;
     auto i = InsBuilder(Op::Cmp);
     i.op1_reg(op1);
     i.op2_reg(op2);
@@ -204,6 +228,7 @@ void Builder::cmp_reg(Reg op1, Reg op2)
 
 void Builder::cmp_imm(Reg op1, uint16_t op2)
 {
+    LOG;
     auto i = InsBuilder(Op::Cmp);
     i.op1_reg(op1);
     i.imm(op2);
@@ -212,101 +237,121 @@ void Builder::cmp_imm(Reg op1, uint16_t op2)
 
 void Builder::or_reg(Reg dst, Reg op1, Reg op2)
 {
+    LOG;
     binary_reg(dst, op1, op2, Op::Or);
 }
 
 void Builder::and_reg(Reg dst, Reg op1, Reg op2)
 {
+    LOG;
     binary_reg(dst, op1, op2, Op::And);
 }
 
 void Builder::xor_reg(Reg dst, Reg op1, Reg op2)
 {
+    LOG;
     binary_reg(dst, op1, op2, Op::Xor);
 }
 
 void Builder::shl_reg(Reg dst, Reg op1, Reg op2)
 {
+    LOG;
     binary_reg(dst, op1, op2, Op::Shl);
 }
 
 void Builder::rshl_reg(Reg dst, Reg op1, Reg op2)
 {
+    LOG;
     binary_reg(dst, op1, op2, Op::RShl);
 }
 
 void Builder::shr_reg(Reg dst, Reg op1, Reg op2)
 {
+    LOG;
     binary_reg(dst, op1, op2, Op::Shr);
 }
 
 void Builder::rshr_reg(Reg dst, Reg op1, Reg op2)
 {
+    LOG;
     binary_reg(dst, op1, op2, Op::RShr);
 }
 
 void Builder::add_reg(Reg dst, Reg op1, Reg op2)
 {
+    LOG;
     binary_reg(dst, op1, op2, Op::Add);
 }
 
 void Builder::sub_reg(Reg dst, Reg op1, Reg op2)
 {
+    LOG;
     binary_reg(dst, op1, op2, Op::Sub);
 }
 
 void Builder::rsub_reg(Reg dst, Reg op1, Reg op2)
 {
+    LOG;
     binary_reg(dst, op1, op2, Op::RSub);
 }
 
 void Builder::or_imm(Reg dst, Reg op1, uint16_t op2)
 {
+    LOG;
     binary_imm(dst, op1, op2, Op::Xor);
 }
 
 void Builder::and_imm(Reg dst, Reg op1, uint16_t op2)
 {
+    LOG;
     binary_imm(dst, op1, op2, Op::And);
 }
 
 void Builder::xor_imm(Reg dst, Reg op1, uint16_t op2)
 {
+    LOG;
     binary_imm(dst, op1, op2, Op::Xor);
 }
 
 void Builder::shl_imm(Reg dst, Reg op1, uint16_t op2)
 {
+    LOG;
     binary_imm(dst, op1, op2, Op::Shl);
 }
 
 void Builder::rshl_imm(Reg dst, Reg op1, uint16_t op2)
 {
+    LOG;
     binary_imm(dst, op1, op2, Op::RShl);
 }
 
 void Builder::shr_imm(Reg dst, Reg op1, uint16_t op2)
 {
+    LOG;
     binary_imm(dst, op1, op2, Op::Shr);
 }
 
 void Builder::rshr_imm(Reg dst, Reg op1, uint16_t op2)
 {
+    LOG;
     binary_imm(dst, op1, op2, Op::RShr);
 }
 
 void Builder::add_imm(Reg dst, Reg op1, uint16_t op2)
 {
+    LOG;
     binary_imm(dst, op1, op2, Op::Add);
 }
 
 void Builder::sub_imm(Reg dst, Reg op1, uint16_t op2)
 {
+    LOG;
     binary_imm(dst, op1, op2, Op::Sub);
 }
 
 void Builder::rsub_imm(Reg dst, Reg op1, uint16_t op2)
 {
+    LOG;
     binary_imm(dst, op1, op2, Op::RSub);
 }
 
@@ -330,12 +375,14 @@ void Builder::binary_imm(Reg dst, Reg op1, uint16_t op2, Op op)
 
 void Builder::reti()
 {
+    LOG;
     auto i = InsBuilder(Op::RetI);
     i.build(*this);
 }
 
 void Builder::lvcd_reg(Reg op1)
 {
+    LOG;
     auto i = InsBuilder(Op::LVCD);
     i.op1_reg(op1);
     i.build(*this);
@@ -343,6 +390,7 @@ void Builder::lvcd_reg(Reg op1)
 
 void Builder::lvcd_imm(uint16_t op1)
 {
+    LOG;
     auto i = InsBuilder(Op::LVCD);
     i.imm(op1);
     i.build(*this);
@@ -350,6 +398,7 @@ void Builder::lvcd_imm(uint16_t op1)
 
 void Builder::lkbd_reg(Reg op1)
 {
+    LOG;
     auto i = InsBuilder(Op::LKBD);
     i.op1_reg(op1);
     i.build(*this);
@@ -357,6 +406,7 @@ void Builder::lkbd_reg(Reg op1)
 
 void Builder::lkbd_imm(uint16_t op1)
 {
+    LOG;
     auto i = InsBuilder(Op::LKBD);
     i.imm(op1);
     i.build(*this);
@@ -364,6 +414,7 @@ void Builder::lkbd_imm(uint16_t op1)
 
 void Builder::dskr(Reg dst, Reg op1)
 {
+    LOG;
     auto i = InsBuilder(Op::DSKR);
     i.dst_reg(dst);
     i.op1_reg(op1);
@@ -372,6 +423,7 @@ void Builder::dskr(Reg dst, Reg op1)
 
 void Builder::dskw(Reg dst, Reg op1)
 {
+    LOG;
     auto i = InsBuilder(Op::DSKW);
     i.dst_reg(dst);
     i.op1_reg(op1);
diff --git a/src/main.cpp b/src/main.cpp
index 2456ead..b1479ae 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -24,6 +24,15 @@ int main(int argc, char** argv)
 
         make_program(disk.data());
 
+        std::println("memory disk");
+        for (size_t i = 0; i < 64; i += 4) {
+            std::println("{:02x} {:02x} {:02x} {:02x}",
+                disk.data()[i],
+                disk.data()[i + 1],
+                disk.data()[i + 2],
+                disk.data()[i + 3]);
+        }
+
         auto vm = VM(*device, disk);
         vm.run();
     } else {
@@ -38,18 +47,13 @@ int main(int argc, char** argv)
         auto memory_block = std::vector<uint8_t>(BlockDevice::block_size);
         memory_disk.read(memory_block.data(), 0);
 
-        std::println("file           memory");
+        std::println("file disk");
         for (size_t i = 0; i < 64; i += 4) {
-            std::println(
-                "{:02x} {:02x} {:02x} {:02x}    {:02x} {:02x} {:02x} {:02x}",
+            std::println("{:02x} {:02x} {:02x} {:02x}",
                 file_block[i],
                 file_block[i + 1],
                 file_block[i + 2],
-                file_block[i + 3],
-                memory_block[i],
-                memory_block[i + 1],
-                memory_block[i + 2],
-                memory_block[i + 3]);
+                file_block[i + 3]);
         }
 
         auto vm = VM(*device, disk);