diff --git a/lua-temp/doc/OPCODES b/lua-temp/doc/OPCODES
index 9faba1e..41828c9 100644
--- a/lua-temp/doc/OPCODES
+++ b/lua-temp/doc/OPCODES
@@ -45,8 +45,8 @@ Function operations:
 Table and array operations:
 16              getkv                Get table's value based on key (pull 1 value, push 1 value)
 17              setkv                Set table's key and value (pull 2 values from stack)
-  a8  c8 e8     geta                 Get array's position value
-  a9  c9 e9     seta                 Set array's position value
+  a8  c8 e8     geti                 Get array's position value
+  a9  c9 e9     seti                 Set array's position value
 18              appnd                Add value to the end of array
 19              next                 Push the next pair into the stack (for loops)
 1a              smt                  Set value metatable
diff --git a/lua-temp/tests.lua b/lua-temp/tests.lua
index e209941..ca81f94 100755
--- a/lua-temp/tests.lua
+++ b/lua-temp/tests.lua
@@ -341,21 +341,21 @@ do TEST "VM: GC strings"
 end
 
 do TEST "VM: arrays"
-    local vm = VM.new():set_debug(true):load(assemble [
+    local vm = VM.new():set_debug(true):load(assemble [[
         .func 0
             newa
             pushi   10
-            seta    0
+            seti    0
             pushi   20
-            seta    1
+            seti    1
             pushi   30
-            seta    2
-            geta    1
-    ]):call(0)
+            seti    2
+            geti    1
+            ret
+    ]]):call(0)
 
     print(vm:debug_heap())
     assert_eq(vm:to_integer(-1), 20)
-    assert_eq(vm:is(-2, 'array'), true)
     assert_eq(vm.heap:size(), 1)
 end
 
diff --git a/lua-temp/tyche-vm.lua b/lua-temp/tyche-vm.lua
index 8fb6c61..1057613 100644
--- a/lua-temp/tyche-vm.lua
+++ b/lua-temp/tyche-vm.lua
@@ -29,6 +29,8 @@ local function validate_value(v)
         assert(type(v.value) == 'number' and v.value >= 0, "function must be a positive number")
     elseif v.type == 'string' then
         assert(type(v.ref) == 'number' or type(v.const_ref) == 'number')
+    elseif v.type == 'array' then
+        assert(type(v.ref) == 'number')
     end
 end
 
@@ -228,6 +230,7 @@ function Heap:add_value(value)
 end
 
 function Heap:get_value(key)
+    assert(type(key) == 'number')
     return self.items[key]
 end
 
@@ -307,6 +310,11 @@ function VM:push_nil()
     return self
 end
 
+function VM:new_array()
+    self.stack:push({ type = 'array', ref = self.heap:add_value({}) })
+    return self
+end
+
 --
 -- information
 --
@@ -316,6 +324,8 @@ function VM:stack_sz()
 end
 
 function VM:is(idx, type_)
+    assert(type(idx) == "number")
+    assert(TYPE_MAP[type_])
     return self.stack[idx].type == type_
 end
 
@@ -337,6 +347,14 @@ function VM:_extract_string(value)
     end
 end
 
+function VM:_extract_array(value)
+    assert(value)
+    assert(value.type == 'array')
+    local array = self.heap:get_value(value.ref)
+    if type(array) ~= 'table' then error('Expected array') end
+    return self.heap:get_value(value.ref)
+end
+
 function VM:to_string(idx)
     local value = self.stack[idx]
     if value.type ~= 'string' then error("Type error: not a string") end
@@ -348,6 +366,11 @@ function VM:format_value(v)
         return tostring(v.value)
     elseif v.type == 'string' then
         return self_:extract_string(v)
+    elseif v.type == 'array' then
+        local array = self:_extract_array(v)
+        local tbl = {}
+        for _,vv in ipairs(array) do table.insert(tbl, self:format_value(vv)) end
+        return "[" .. table.concat(tbl, ', ') .. "]"
     elseif v.type == 'function' then
         return '@' .. tostring(v.value)
     elseif v.type == 'nil' then
@@ -365,7 +388,7 @@ function VM:debug_stack()
         for _,fp in pairs(self.stack.fps) do
             if i == fp then table.insert(ss, '^ ') end
         end
-        table.insert(ss, '[' .. self:format_value(v) .. '] ')
+        table.insert(ss, self:format_value(v) .. ' ')
     end
     return table.concat(ss)
 end
@@ -373,12 +396,7 @@ end
 function VM:debug_heap()
     local ss = { "Heap:\n" }
     for k,v in pairs(self.heap.items) do
-        table.insert(ss, string.format("  [%X] = ", k))
-        if type(v) == 'string' then
-            table.insert(ss, '"' .. v .. '"')
-        else
-            error('Unsupported value in heap')
-        end
+        table.insert(ss, string.format("  [%X] = %s", k, pprint.pformat(v)))
         table.insert(ss, "\n")
     end
     return table.concat(ss)
@@ -459,6 +477,9 @@ function VM:_step()
             error('REAL consts not supported for now.')
         end
 
+    elseif op.operator == 'newa' then
+        self:new_array()
+
     elseif op.operator == 'pop' then
         self.stack:pop()
 
@@ -485,6 +506,20 @@ function VM:_step()
         local a = self.stack[op.operand]
         self.stack:push(a)
 
+    --
+    -- table and array operations
+    --
+
+    elseif op.operator == 'seti' then
+        local array_ref = self.stack[-2]
+        local array = self:_extract_array(array_ref)
+        array[op.operand+1] = self.stack:pop()
+
+    elseif op.operator == 'geti' then
+        local array_ref = self.stack[-1]
+        local array = self:_extract_array(array_ref)
+        self.stack:push(array[op.operand+1])
+
     --
     -- logic/arithmetic operations
     --