Fully discrete 74LS138

The 74LS138 triple-eight decoder is made using discrete components and uses DTL circuitry. The power supply voltage 5V
test has been completed.
Flying lines on the PCB are caused by Lichuang EDAbug, so just ignore them and directly make a sample.
①When one strobe terminal (E1) is high level and the other two strobe terminals () and () are low level, the binary encoding of the address terminals (A0, A1, A2) can be in the corresponding positions of Y0 to Y7 The output terminal is decoded at low level. (That is, the output is the negation of Y0 to Y7) For example: when A2A1A0=110, the Y6 output terminal outputs a low level signal.
②Using E1, E2 and E3, it can be cascaded and expanded into a 24-line decoder; if an external inverter is connected, it can also be cascaded and expanded into a 32-line decoder.
③If one of the strobe terminals is used as a data input terminal, 74LS138 can also be used as a data distributor.
④Can be used in the decoding circuit of 8086 to expand the memory