Connecting to a 20x4 LCD display

This is the LCD 20x4 board for the I/O bus (see the specs for the reZet80 I/O bus).

20x4 (20 characters, 4 lines) LCD modules provide a parallel interface and are wired as follows:

 1: GND
 2: +5V
 3: V0
 4: RS  [A0]
 5: R/W  [/WR]
 6: E  [IOSEL inverted]
 7: DB0  [D0]
 8: DB1  [D1]
 9: DB2  [D2]
10: DB3  [D3]
11: DB4  [D4]
12: DB5  [D5]
13: DB6  [D6]
14: DB7  [D7]
15: VDD backlight
16: GND backlight

A variable 4.7k resistor connected to V0 is used to set the display contrast.
A 3.3R resistor is connected between LCD pin 16 and GND if VDD backlight is less than 5V (please check your specs!), otherwise connect pin 16 directly to GND.

Bill of materials:
- PCB 5x7 cm (at least 23 rows)
- 23-pin right-angled male connector
- DIP-14 socket
- DIP-20 socket
- 74x04 hex inverter
- 74x245 octal bidirectional transceiver
- resistor 3.3R (choose according to the LCD specs)
- variable resistor 4k7
- capacitor 100 nF

playing around with the RTC