Quantity   Component name
6 × PIC 16F 627A 4x for 7 segment display control; + 1x for LCD (20x4) display control; + 1x for ROM control
1 × 4x20 characters LCD Display with green backlight For displaying data and programming the computer
1 × 24256 ROM chip For permanent data storage
1 × PIC 16LF 723A For keyboard interface (enough pins to read 30 button with the help of multiplexing [3x10])
2 × PIC 16F 884 The quantity may still rise, but for now: 1 x as CPU + 1 x as ASM compiler