diff --git a/nac3artiq/src/codegen.rs b/nac3artiq/src/codegen.rs
index 83fa247c..07b3733a 100644
--- a/nac3artiq/src/codegen.rs
+++ b/nac3artiq/src/codegen.rs
@@ -32,7 +32,6 @@ use crate::{symbol_resolver::InnerResolver, timeline::TimeFns};
 use inkwell::types::BasicType;
 use itertools::Itertools;
 use nac3core::codegen::classes::{ArrayLikeIndexer, ArrayLikeValue, ArraySliceValue, NDArrayType};
-use nac3core::codegen::llvm_intrinsics;
 use std::{
     collections::{hash_map::DefaultHasher, HashMap},
     hash::{Hash, Hasher},
@@ -431,7 +430,8 @@ fn gen_rpc_tag(
                 );
 
                 buffer.push(b'a');
-                buffer.push((ndarray_ndims & 0xFF) as u8);
+                buffer.push(1u8);
+                // buffer.push((ndarray_ndims & 0xFF) as u8);
                 gen_rpc_tag(ctx, ndarray_dtype, buffer)?;
             }
             _ => return Err(format!("Unsupported type: {:?}", ctx.unifier.stringify(ty))),
@@ -578,26 +578,52 @@ fn rpc_codegen_callback_fn<'ctx>(
 
             let buffer_size = ctx.builder.build_int_add(dims_buf_sz, data_buf_sz, "").unwrap();
 
-            let buffer = ctx.builder.build_array_alloca(int8, buffer_size, "").unwrap();
+            // let buffer = ctx.builder.build_array_alloca(int8, buffer_size, "").unwrap();
+            let buffer = ctx.builder.build_array_alloca(int8, size_type.const_int(28, false), "").unwrap();
             let buffer = ArraySliceValue::from_ptr_val(buffer, buffer_size, None);
 
-            llvm_intrinsics::call_memcpy_generic(
-                ctx,
-                buffer.base_ptr(ctx, generator),
-                llvm_arg.dim_sizes().base_ptr(ctx, generator),
-                dims_buf_sz,
-                int1.const_zero(),
-            );
+            for (offset, byte) in [
+                /* LSB <-> MSB */
+                /* buffer[0] */ 0u8, 0u8, 0u8, 0u8,
+                /* buffer[4] */ 2u8, 0u8, 0u8, 0u8,
+                /* buffer[8] */ 0u8, 0u8, 0u8, 0u8,
+                /* buffer[12] */ 128u8, 0u8, 0u8, 0u8,
+                /* buffer[16] */ 0u8, 0u8, 0u8, 0u8,
+                /* buffer[20] */ 0u8, 0u8, 0u8, 0u8,
+                /* buffer[24] */ 0u8, 0u8, 0u8, 0u8,
+                // /* buffer[28] - data[2] */ 128u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+                // /* buffer[36] - data[3] */ 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8,
+            ].into_iter().enumerate()
+            {
+                let pbuffer = unsafe {
+                    buffer.ptr_offset_unchecked(
+                        ctx,
+                        generator,
+                        &size_type.const_int(offset as u64, false),
+                        None,
+                    )
+                };
 
-            let pbuffer_data_begin =
-                unsafe { buffer.ptr_offset_unchecked(ctx, generator, &dims_buf_sz, None) };
-            llvm_intrinsics::call_memcpy_generic(
-                ctx,
-                pbuffer_data_begin,
-                llvm_arg.data().base_ptr(ctx, generator),
-                data_buf_sz,
-                int1.const_zero(),
-            );
+                ctx.builder.build_store(pbuffer, int8.const_int(byte as u64, false)).unwrap();
+            }
+
+            // llvm_intrinsics::call_memcpy_generic(
+            //     ctx,
+            //     buffer.base_ptr(ctx, generator),
+            //     llvm_arg.dim_sizes().base_ptr(ctx, generator),
+            //     dims_buf_sz,
+            //     int1.const_zero(),
+            // );
+            //
+            // let pbuffer_data_begin =
+            //     unsafe { buffer.ptr_offset_unchecked(ctx, generator, &dims_buf_sz, None) };
+            // llvm_intrinsics::call_memcpy_generic(
+            //     ctx,
+            //     pbuffer_data_begin,
+            //     llvm_arg.data().base_ptr(ctx, generator),
+            //     data_buf_sz,
+            //     int1.const_zero(),
+            // );
 
             buffer.base_ptr(ctx, generator)
         } else {