Editing Psion Organiser II

{{Infobox computer
| name         = Psion Organiser II
| image        = [[File:Psion Organiser II.jpg|250px]]
| caption      = A Psion Organiser II with the sliding cover retracted
| developer    = Psion Ltd
| manufacturer = Psion Ltd
| type         = Handheld pocket computer
| release_date = 1986
| discontinued = Early 1990s
| cpu          = Hitachi HD6303X 8-bit CMOS @ 0.9216 MHz (3.6864 MHz crystal ÷ 4)
| memory       = 8 KB (CM), 16 KB (XP), 32 KB (LA / LZ) or 64 KB (LZ64) RAM; 32 KB or 64 KB ROM
| storage      = Two side slots for Datapaks, Rampaks and Flashpaks; one top slot for devices
| display      = 2 × 16 characters (CM/XP/LA) or 4 × 20 characters (LZ/LZ64), dot matrix LCD
| sound        = Piezoelectric buzzer
| dimensions   = 142 mm × 78 mm × 29.3 mm (cover closed)
| weight       = Approximately 225 g with battery
| os           = Psion Organiser II operating system in ROM, with OPL
| predecessor  = [[Psion Organiser]]
| model        = CM, XP, XP(LA), Multilingual XP(LA), LZ, LZ64, plus POS 200, P250, P350, P432 and P464 industrial variants
}}
The '''Psion Organiser II''' is the machine that made Psion's name. Launched in 1986, it replaced the [[Psion Organiser|Series 1]] with a real operating system, a two-line display, a programming language ('''OPL'''), a top slot for peripherals, and a range that eventually stretched from an 8 KB consumer model to ruggedised point-of-sale terminals used in industry well into the 1990s.

Internally it is an '''8-bit CMOS computer''': a Hitachi HD6303X processor, a semi-custom control IC that handles memory decoding, the real-time clock, keyboard polling and power sequencing, and a Hitachi HD44780/HD44100 LCD driver pair — all surface-mounted on a system board, with a separate through-hole power supply board joined to it by a 27-way strip connector.<ref name="tech2">''Psion Organiser II Technical Manual'', Psion Ltd, 1986, Chapter 2 "System Board", transcribed at [https://www.jaapsch.net/psion/tech02.htm Jaap's Psion Organiser II Page]. Source for the system board device list, memory map, memory options and links, keyboard matrix, real-time clock divider chain and LCD interface described on this page.</ref>

== Models ==

[[File:Psion Organiser II two-line and four-line models.jpg|thumb|353x353px|Three Organiser IIs. Left: closed, with the sliding cover in place. Centre: a two-line model. Right: a four-line LZ — the taller screen aperture is the quickest way to tell them apart.]]

=== Consumer models ===

The first Series II machines appeared in 1986 with a '''two-line''' display. The '''CM''' had 8 KB of RAM and the '''XP''' 16 KB; the XP was almost immediately upgraded to 32 KB and, although the casing still said XP, that machine is usually called the '''LA'''. All of these had a 32 KB ROM. A multilingual XP was later produced with an extra two 16 KB ROM banks — 64 KB in total — to hold eleven languages.<ref name="models">[https://www.jaapsch.net/psion/models.htm Psion Organiser II Models and Version Numbers], Jaap's Psion Organiser II Page. Source for the model history, the PEEKB identification tables, the language codes, the ROM version table and the POS variant list.</ref>

In 1989 Psion introduced the '''four-line''' machines. The '''LZ''' has 32 KB of RAM and the '''LZ64''' 64 KB (32 KB plus two 16 KB banks). They look almost identical to the earlier machines apart from the slightly taller screen. All were multilingual, normally English plus two others.<ref name="models" />

{| class="wikitable styled-table" style="width:70%; text-align:left;"
|+'''Consumer models'''<ref name="models" />
! Model !! ROM !! RAM !! Display !! Notes
|-
| '''CM''' || 32 KB || 8 KB || 2 × 16 || The entry model
|-
| '''XP''' || 32 KB || 16 KB || 2 × 16 || Short-lived
|-
| '''XP (LA)''' || 32 KB || 32 KB || 2 × 16 || Cased as an XP; by far the commonest two-line machine
|-
| '''Multilingual XP (LA)''' || 64 KB || 32 KB || 2 × 16 || Eleven language options
|-
| '''LZ''' || 64 KB || 32 KB || 4 × 20 || 1989; three languages
|-
| '''LZ64''' || 64 KB || 64 KB || 4 × 20 || 32 KB plus two 16 KB banks
|}

=== POS and industrial variants ===

Psion produced a series of point-of-sale and industrial machines. A POS model does not show a menu when switched on: it looks on the fitted packs for a procedure called '''BOOT''' and runs it. If it cannot find one it displays "PACK?" or "INSERT PACK?" briefly and switches off again. Many have non-standard keyboards.<ref name="models" />

{| class="wikitable styled-table" style="width:70%; text-align:left;"
|+'''POS and industrial variants'''<ref name="models" />
! Model !! ROM !! RAM !! Display !! Keyboard
|-
| POS 200 || 32 KB || 16 or 32 KB || 2 × 16 || Numeric
|-
| Alpha POS 200 || 32 KB || 16 or 32 KB || 2 × 16 || Alphanumeric
|-
| P 250 || 32 KB || 16 or 32 KB || 2 × 16 || Full
|-
| P 350 || 32 KB || 96 KB || 2 × 16 || Full
|-
| P 432 || 64 KB || 32 KB || 4 × 20 || Full
|-
| P 464 || 64 KB || 64 KB || 4 × 20 || Full
|}

'''A POS machine that "switches itself off immediately" is not faulty''' — it is looking for a BOOT procedure it cannot find.

== Identifying your machine ==

Everything can be read out from the calculator. Select '''CALC''' from the main menu and evaluate the following:<ref name="models" />

{| class="wikitable styled-table" style="width:65%; text-align:left;"
|+'''Identification by PEEKB'''<ref name="models" />
! Expression !! Returns
|-
| <code>PEEKB(-24)</code> || The model
|-
| <code>PEEKB(-25)</code> || The language option
|-
| <code>PEEKB(-23)</code> || The ROM version, as a binary-coded decimal — <code>$46</code> means version 4.6
|-
| <code>PEEKB(8441)</code> || The version of a top-slot device's software (press ON/CLEAR at the main menu first, to make sure it is loaded)
|-
| <code>PEEKB(8421)</code> / <code>PEEKB(8431)</code> || Version of a bootable pack in slot B: or C: respectively
|-
| <code>8*PEEKB(8418)</code> / <code>8*PEEKB(8428)</code> || The size of the pack in slot B: or C:
|}

{| class="wikitable styled-table" style="width:75%; text-align:left;"
|+'''PEEKB(-24) — model'''<ref name="models" />
! Value !! Model !! !! Value !! Model
|-
| 0 || CM || || 129, 130 || POS 200
|-
| 1 || XP || || 65, 66 || Alpha POS 200
|-
| 2 || XP (LA), or Multilingual XP (LA) || || 17, 18 || P 250
|-
| 14 || LZ || || 20 || P 350
|-
| 13 || LZ64 || || 30 / 29 || P 432 / P 464
|}

{| class="wikitable styled-table" style="width:75%; text-align:left;"
|+'''PEEKB(-25) — language'''<ref name="models" />
! Value !! Language options
|-
| 255 || Not set (earliest versions)
|-
| 0 / 1 / 2 || English only / French only / German only (CM, XP, LA)
|-
| 128 || Eleven languages (Multilingual LA)
|-
| 129 || English, French, German (LZ / LZ64)
|-
| 130 || English, Italian, Spanish (LZ / LZ64)
|-
| 131 || English, Swedish, Danish (LZ / LZ64)
|}

ROM versions run '''2.4 to 2.6''' on early CM/XP machines, '''3.0 to 3.7''' on CM/LA, '''3.8''' on the POS 350, and '''4.2 to 4.6''' on the LZ and LZ64.<ref name="models" />

== System board ==

The system board is a CMOS 8-bit computer carrying the processor, ROM, RAM, LCD drivers and the control IC, with the keyboard contacts printed directly on it. All the ICs are surface-mount, and there are eight IC positions, some of them optional.<ref name="tech2" />

{| class="wikitable styled-table" style="width:100%; text-align:left;"
|+'''System board devices'''<ref name="tech2" /><ref name="spares">''Psion Organiser II Spare Parts List v3'', Psion. Hosted on this wiki as [[:File:Psion Organiser II Spare Parts List v3.pdf]]. Source for the device identities per board variant, the capacitor and resistor values, the LCD connector, buzzer, keymat and interboard connector part numbers.</ref>
! Position !! Device !! Function
|-
| '''IC1''' || '''HD6303XFP''' (80-pin flat pack) || 8-bit CPU derived from the 6800 family, 0.9216 MHz
|-
| '''IC2''' || '''HD44780''' (XP), '''HD66780''' (LZ) || Master LCD driver with character-generator ROM and display RAM
|-
| '''IC3''' (and IC9 on LZ) || '''HD44100H''' (XP), '''HD66100''' (LZ) || Slave segment driver, extending the display width
|-
| '''IC4''' || '''NEC µPD65006 GB-314''' (XP) or '''Texas Instruments CF70043''' (LZ) || Semi-custom control IC — memory decode, real-time clock, keyboard polling, power sequencing, buzzer and pump control
|-
| '''IC5 / IC6''' || '''27C64FP''' (8 KB) or '''27C256FP''' (32 KB) OTP CMOS EPROM || System firmware. IC5 always fitted; IC6 only for the two-chip 16 KB option
|-
| '''IC7 / IC8''' || '''6264LFP''' (8 KB) or '''62256LFP''' / KM62256BLG (32 KB) static RAM, 150–250 ns || User RAM, powered at all times so it survives switch-off
|-
| '''X1 / XL1''' || '''3.6864 MHz''' crystal || Processor clock, divided by four internally
|-
| — || '''32768 Hz''' crystal || Real-time clock oscillator
|}

The ROMs draw about '''1 µA''' in standby and the RAMs about '''2 µA''', which is why data survives with the machine off.<ref name="tech2" />

=== Memory map ===

{| class="wikitable styled-table" style="width:85%; text-align:left;"
|+'''HD6303X memory map'''<ref name="tech2" />
! Range !! Assignment
|-
| <code>$8000–$FFFF</code> || External PROM — 8, 16 or 32 KB, filled from the top down
|-
| <code>$0400–$7FFF</code> || External RAM — 8, 16 or 31 KB, filled from <code>$2000</code> up (except the 31 KB option, from <code>$0400</code>)
|-
| <code>$0100–$03FF</code> || External I/O — the LCD and the control IC's latches
|-
| <code>$0000–$00FF</code> || Processor internal RAM and registers (192 bytes of RAM at <code>$0040–$00FF</code>, also retained when off)
|}

The memory-mapped I/O block is decoded in 64-byte pages, and every one of these is '''address-triggered''': any access at all, read or write, causes the event.<ref name="tech2" />

{| class="wikitable styled-table" style="width:70%; text-align:left;"
|+'''Memory-mapped I/O'''<ref name="tech2" />
! Range !! Function !! !! Range !! Function
|-
| <code>$0180–$01BF</code> || LCD ENABLE || || <code>$0300–$033F</code> || COUNTER RESET
|-
| <code>$01C0–$01FF</code> || SWITCH OFF || || <code>$0340–$037F</code> || COUNTER CLOCK
|-
| <code>$0200–$023F</code> || PULSE ENABLE || || <code>$0380–$03BF</code> || NMI ENABLE
|-
| <code>$0240–$027F</code> || PULSE DISABLE || || <code>$03C0–$03FF</code> || NMI DISABLE
|-
| <code>$0280–$02BF</code> || ALARM SET || || <code>$02C0–$02FF</code> || ALARM RESET
|}

=== Memory decode links ===

Six chip-select outputs (CS1_B–CS6_B) come out of the control IC, and '''links L1–L8''' on the board — arranged as four pairs, of which only one of each pair is fitted — route them to whichever memory devices are present.<ref name="tech2" />

{| class="wikitable styled-table" style="width:100%; text-align:left;"
|+'''Production link options'''<ref name="tech2" />
! Version !! PROM !! RAM !! Links fitted
|-
| '''CM''' || 32 KB at <code>$8000–$FFFF</code> || 8 KB at <code>$2000–$3FFF</code> || L1, L4, L5, L7
|-
| '''XP''' || 32 KB at <code>$8000–$FFFF</code> || 8 KB at <code>$2000–$3FFF</code> plus 8 KB at <code>$4000–$5FFF</code> || L1, L4, L5, L7
|-
| '''LA''' || 32 KB at <code>$8000–$FFFF</code> || 32 KB at <code>$0400–$7FFF</code> || L1, L4, L6, L7
|}

=== Keyboard ===

The '''AC''' key (top left) is special: it is wired straight to the control IC and to port 5 bit 7, and it is what switches the machine on. The other '''35 keys form a 7 × 5 matrix'''. The seven outputs K1–K7 are open-drain and are pulled low one at a time; the processor reads KBD1–KBD5 on port 5 bits 2–6, and a low means a key is down. The switches are '''PCB pads under the keys, shorted by a conductive rubber pad'''.<ref name="tech2" />

The K1–K7 outputs are not a dedicated peripheral — they are '''bits 1–7 of the second stage of the real-time clock divider chain''', which is why the keyboard can only be polled when the NMI latch is set to interrupt the processor directly.<ref name="tech2" />

The Technical Manual's published key matrix is reproduced below. '''Note that as printed it contains three apparent duplicates (G, S and Y) and omits E and T''', so it should be verified against a real machine before being relied on:<ref name="tech2" />

{| class="wikitable styled-table" style="width:75%; text-align:center;"
|+'''Keyboard matrix as published'''<ref name="tech2" />
! !! KBD5 !! KBD4 !! KBD3 !! KBD2 !! KBD1
|-
! Port 5 bit
| 6 || 5 || 4 || 3 || 2
|-
! K7
| D || J || P || V || S
|-
! K6
| F || L || R || X || EXE
|-
! K5
| G || K || Q || W || DEL
|-
! K4
| C || I || O || U || Z
|-
! K3
| B || H || N || Y || Y
|-
! K2
| A || G || M || S || SH
|-
! K1
| RA || LA || DA || UA || MODE
|}

Even with those errors, the structure is what matters for repair: '''a dead row is one K output, a dead column is one KBD input.'''

=== Real-time clock and the 34-minute wake-up ===

The control IC contains a '''27-bit divider chain''' split into two stages. Stage 1 is a 15-bit counter clocked at 32768 Hz, so its top bit runs at 1 Hz. Stage 2 is a 12-bit counter.<ref name="tech2" />

While the machine is on, the 1 Hz signal goes to the processor's NMI input and the clock is updated every second. When the machine is switched off, the 1 Hz signal is instead routed to stage 2, and when stage 2 times out — after '''34 minutes and 8 seconds''' — it '''switches the Organiser on by itself''', lets the processor add 34 min 8 s to its time registers, and switches off again.<ref name="tech2" />

That is why an Organiser left switched off still keeps good time, and it is also why a machine sitting in a drawer draws a little more power than a pure standby figure would suggest.

=== 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>

== Power supply board ==

The power supply board regulates and distributes power, and also carries the signals through to the three external device connectors and the buzzer. It works from a supply of '''5.5 to 11 V''' and delivers currents from 30 µA to 170 mA depending on state.<ref name="tech3" />

{| class="wikitable styled-table" style="width:100%; text-align:left;"
|+'''Supply rails'''<ref name="tech3" />
! Rail !! Purpose !! Voltage !! Typical load
|-
| '''VCC1''' || Main system board supply, '''always present'''. Keeps the real-time clock running and the RAM alive when off || 3–5 V when off; 5 V ±5 % when on || 30 µA off; up to 25 mA on
|-
| '''VCC2''' || System board LCD drivers || 5 V ±5 % when on || ~1 mA
|-
| '''V_LCD''' || Negative rail for the LCD, set by the thumbwheel || Adjustable between about +1.2 V and −3 V || 100–300 µA
|-
| '''SVCC''' || Supply to the external slot devices, switched under software control || 5 V ±5 % || up to 170 mA
|-
| '''SVPP''' || Secondary rail to slots 1 and 2 || 4.5 V normally; '''21 V ±2 % pulsed''' when programming Datapaks || 50 mA for 50 ms bursts
|}

{| class="wikitable styled-table" style="width:100%; text-align:left;"
|+'''Operating states'''<ref name="tech3" />
! State !! ON_B !! PACON_B !! VCC1 !! VCC2 !! V_LCD !! SVCC !! SVPP !! Total draw
|-
| 1 — off || high || high || 3–5 V || off || off || off || off || ~40 µA
|-
| 2 — on, slots off || low || high || 5 V || 5 V || −3 to +1 V || off || off || ~25 mA running, ~4 mA asleep
|-
| 3 — slots on || low || low || 5 V || 5 V || −3 to +1 V || 5 V || 4.5 V || ~25 mA plus devices
|-
| 4 — programming || low || low || 5 V || 5 V || −3 to +1 V || 5 V || '''21 V''' || pulsed
|}

The '''21 V programming voltage''' is produced in two stages: an inductor-based pump charges a storage capacitor towards 35 V, a zener sets a READY flag once it is high enough, and a regulator then puts 21 V onto SVPP long enough to program one EPROM byte. The software must not leave the pump enabled — Psion warn that damage can occur if PULSE is left running.<ref name="tech3" />

The '''buzzer''' is a 27 mm piezoelectric element driven directly from the ALARM latch through a 1 kΩ resistor. It only makes a sound on ''transitions'' of that signal, so tones are produced by the software toggling ALARM set and reset.<ref name="tech3" /><ref name="spares" /> The ALARM signal is '''also an interlock for the programming voltage''', which imposes restrictions on using the buzzer while the slots are powered.<ref name="tech3" />

=== Battery ===

The Organiser II runs from a '''9 V PP3''', which must be a low-internal-resistance type because the system draws peaks of 200 mA.<ref name="tech3" />

{| class="wikitable styled-table" style="width:75%; text-align:left;"
|+'''PP3 types'''<ref name="tech3" />
! Type !! Rechargeable !! Typical capacity
|-
| Long-life alkaline || No || 400–500 mAh
|-
| Nickel-cadmium || Yes || 100 mAh between charges
|}

A new cell reads up to '''10.5 V''' off-load and falls through its life to the '''5.5 V''' system minimum.<ref name="tech3" />

== Packs and the top slot ==

[[File:Psion Organiser Datapak.jpg|thumb|300px|A Datapak. The EPROM inside can only be erased optically, so deleted records still occupy space until the pak is UV-formatted.]]

The Organiser II has '''two side slots''' for storage packs and '''one top slot''' for devices such as the Comms Link, bar code readers and printers. Storage came in three forms:

* '''Datapaks''' — EPROM, in 8 KB, 16 KB, 32 KB, 64 KB and 128 KB sizes. Non-volatile and effectively permanent, but only erasable under ultraviolet light.
* '''Rampaks''' — static RAM with a backup cell, in 32 KB, 64 KB, 128 KB and 256 KB sizes. Rewritable, but dependent on their internal battery.
* '''Flashpaks''' — flash memory, 128 KB and 256 KB, using a 28F010 device.<ref name="datasheets">[https://www.jaapsch.net/psion/datasheets.htm Psion Organiser II Datasheets and Schematics], Jaap's Psion Organiser II Page. Source for the pack memory devices (27C64, 27C128, 27C256, 27C512, D27011, 28F010) and for the pack and peripheral schematics by Olivier Gossuin.</ref>

Schematics for the 16 K, 32 K, 64 K and 128 K Datapaks, the 32 K and 256 K Rampaks, the 256 K Flashpak, the Comms Link and the ParaLink have been reverse-engineered and published by Olivier Gossuin.<ref name="datasheets" />

'''Never insert or remove a Rampak with the machine powered.''' The backup cell has a low internal resistance, and the sudden power drop when a pack is hot-plugged — or when a hungry top-slot device is switched on — is a known cause of data corruption.<ref name="forum">[https://www.organiser2.com/ PSION Organiser II Forum]. Community source for the Rampak hot-plug data-corruption problem and general Organiser II repair practice.</ref>

== Documentation on this wiki ==

* '''[[:File:Psion Organiser II Spare Parts List v3.pdf|Organiser II Spare Parts List v3]]''' — Psion's own exploded diagram and component-level parts lists, including capacitor values and designators for the PSU and CPU boards.

[[File:Psion Organiser II exploded view.png|thumb|420px|Psion's exploded assembly diagram from the Organiser II Spare Parts List, with the numbered parts table.]]

== General maintenance ==
{{Main|Psion Organiser II General Maintenance}}

Battery leakage, pack slot contacts, the conductive keymat and the LCD's rubber connector strips are the routine concerns. See the [[Psion Organiser II General Maintenance]] guide.

== Troubleshooting ==
{{Main|Psion Organiser II Troubleshooting Guide}}

The Technical Manual documents the rails, the operating states and the current figures well enough for genuinely systematic diagnosis, and the community has found several faults the manual does not cover. See the [[Psion Organiser II Troubleshooting Guide]].

== Capacitor replacement ==
{{Main|Psion Organiser II Capacitor Replacement Guide}}

Psion published component-level values, and the LZ/LZ64's persistent whistle is a known ageing-capacitor fault. See the [[Psion Organiser II Capacitor Replacement Guide]].

== See also ==

* [[Psion Organiser]] — the 1984 Series 1
* [[Battery Refurbishment]]
* [[Battery Explosion, Capacitor or Corrosion Damage]]

== References ==

<references />

{{Navbox-Psion}}

[[Category:Psion]]