How to select 2 tables without join and using difference WHERE clause?

Table t1:     Table t2:
+----+----+  +----+----+
| i1 | i2 |  | d1 | d2 |
+----+----+  +----+----+
| 1  | a  |  | 6  | k  |
| 2  | b  |  | 7  | y  |
| 3  | c  |  | 8  | z  |
+----+----+  +----+----+

How to select 2 tables without join and using difference WHERE clause? I have tried :

SELECT i.1, i.2, d.1, d.2
FROM tbl_t1, tbl_t2
WHERE i.1 = 2 AND d.1 = 8

It show wrong result. Any idea? I want show result as following :

2 == b
8 == z

Answer

Use UNION, which joins vertically and not like join horizontally

SELECT i.i1, i.i2
FROM tbl_t1
WHERE i.i1 = 2 
UNION ALL
SELECT
 d.d1, d.d2 
FROM tbl_t2 d
WHERE  d.d1 = 8