| 制造商 | 部件名 | 数据表 | 功能描述 |
 National Semiconductor ... | DM74LS253N |  158Kb/6P | TRI-STATE Data Selectors/Multiplexers |
 National Semiconductor ... | DM74LS253M |  158Kb/6P | TRI-STATE Data Selectors/Multiplexers |
 National Semiconductor ... | DM74LS251 |  135Kb/6P | TRI-STATE Data Selectors/Multiplexers |
 National Semiconductor ... | DM74LS251M |  135Kb/6P | TRI-STATE Data Selectors/Multiplexers |
 National Semiconductor ... | DM74LS251N |  135Kb/6P | TRI-STATE Data Selectors/Multiplexers |
 National Semiconductor ... | DM74LS253 |  158Kb/6P | TRI-STATE Data Selectors/Multiplexers |
| DM74LS256 |  127Kb/6P | Dual 4-Bit Addressable Latch |
| DM74LS256N |  127Kb/6P | Dual 4-Bit Addressable Latch |
| DM74LS257 |  163Kb/8P | TRI-STATE Quad 2-Data Selectors/Multiplexers |
 National Semiconductor ... | DM74LS257BM |  163Kb/8P | TRI-STATE Quad 2-Data Selectors/Multiplexers |