Editing Psion Organiser II (section)

=== Display ===

The LCD is 32 characters as two lines of 16 (four lines of 20 on the LZ), driven at 1/16 duty. The HD44780 provides the 16 common lines and the first 40 segment lines; the HD44100 slave provides the rest. The panel connects to the board through '''conductive rubber connector strips''' — 96 connections in all, 16 commons and 80 segments.<ref name="tech2" /> Psion's part number for the strip is '''3700 0002, "LCD. CONN. F/PITH 70 × 3.8 mm"'''.<ref name="spares" />

Contrast is set by the '''thumbwheel''', a 10 kΩ potentiometer (VR1) on the power supply board, which adjusts the negative V_LCD rail.<ref name="spares" /><ref name="tech3">''Psion Organiser II Technical Manual'', Psion Ltd, 1986, Chapter 3 "Power Supply Board", transcribed at [https://www.jaapsch.net/psion/tech03.htm Jaap's Psion Organiser II Page]. Source for the supply rails, operating states, standby and active current figures, PP3 battery characteristics, the V_LCD charge pump, the 21 V programming pump and the buzzer drive.</ref>