Most chips and components can be soldered directly on PCB.
It is possible to add LEDs to schematics to display status, instruction opcodes, address and Accumulator data. But that would complicate PCB and make it larger.

Recommended to install EEPROM chips U3 and U15 on a DIP 24 pin socket, so that EEPROM could be easily removed and reprogrammed when needed.

EEPROM chip U3 stores instruction opcode, 8 bits,  EEPROM chip U15 stores address/data.

The CPU program is stored in two EEPROM chips U3 and U15.
A is 8 bits accumulator register.

Here is list of 16 bits binary opcodes:
   data/addr    opcode Hex
           00     00  h - noop
           00     01   h - clear Accumulator A

...address     02  h - jump conditional if overflow
...address     03  h - jump unconditional
......#data..     14  h - add data to A
            00    15 h - add value of A to A 
....address    16  h - add SRAM value to A
.... .....port..    17  h - add value from input port to A
.......#data..    34  h -  subtract data from A
           00     35  h -  subtract value of A from A
....address    36  h - subtract SRAM value from A
..........port..    37  h - subtract value from input port from A
....address    45  h - store value A to SRAM by address
..........port..    85 h  - write value A to output port

Notes:
In each opcode, free bit  x (bit 3) allows to lit LED
          when x is 1 LED is lit.

Port parameter is currently not used. But in future designs it may
be used to select port number.