Josh: Remove the Category:Home Computers link — the category has no page and renders as a red link

2026-09-09T10:50:36Z

Remove the Category:Home Computers link — the category has no page and renders as a red link

← Older revision		Revision as of 11:50, 9 September 2026
Line 136:		Line 136:

	[[Category:Psion]]		[[Category:Psion]]
	~~[[Category:Home Computers]]~~

Josh: Create Psion page set: researched from Psion manuals, service documentation and community repair sources

2026-09-08T23:00:17Z

Create Psion page set: researched from Psion manuals, service documentation and community repair sources

New page

{{Infobox computer
| name = Psion Series 5
| image = [[File:Psion Series 5.jpg|250px]]
| caption = A Psion Series 5 (1997)
| developer = Psion Computers PLC
| manufacturer = Psion Computers PLC
| type = Clamshell palmtop / PDA
| release_date = 1997
| discontinued = Superseded by the Series 5mx in 1999
| cpu = ARM710a core in a Cirrus Logic CL-PS7110 (ARM 7100) @ 18.432 MHz
| memory = 6 MB ROM on a daughter board; 4 MB or 8 MB RAM
| storage = Internal RAM disk; CompactFlash slot
| display = 640 × 240 passive-matrix LCD, 16 greyscales, backlit, with a resistive digitiser
| sound = Speaker, microphone and a button-operated dictaphone
| dimensions = 170 mm × 90 mm × 23 mm
| weight = 354 g including batteries
| os = EPOC32
| predecessor = [[Psion Series 3c]]
| successor = [[Psion Series 5mx]]
| model = Development codename "Protea"
}}
The '''Psion Series 5''' of 1997 is the first EPOC32 machine and the first Psion built on ARM. It introduced the '''sliding keyboard clamshell''' that defines the shape of every later Psion, and the 640 × 240 touchscreen that the [[Psion Series 5mx|5mx]] and [[Psion Revo|Revo]] inherited.<ref name="wp">[https://en.wikipedia.org/wiki/Psion_Series_5 "Psion Series 5"], Wikipedia. Source for the model history, the sliding clamshell patent and designer, the display and keyboard specifications, dimensions, the CPU identification and the statement that Series 5 and 5mx internals are not interchangeable.</ref>

'''Psion published a full service manual for the Series 5''', and it is hosted on this wiki — see [[Psion Series 5 Service Manual]]. That makes this the best-documented machine in the whole Psion range, and much of what follows comes straight from it.<ref name="sm">''Psion Series 5 Service Manual'', Psion Computers PLC, November 1997. Hosted on this wiki as [[:File:Psion Series 5 Service Manual (November 1997).pdf]]. Source for the circuit description, clock frequencies, reset arrangements, LCD, digitiser and keyboard interfaces, ROM board options, spares kits, disassembly and reassembly procedure, standby currents and Final Test fault codes.</ref>

== Series 5 or 5mx? ==

They look almost identical, and '''their mainboards, screens and other internal components are different and not interchangeable'''.<ref name="wp" />

{| class="wikitable styled-table" style="width:100%; text-align:left;"
|+'''Series 5 against Series 5mx'''<ref name="wp" /><ref name="wuffs">Ash Wolf (Ninji), [https://wuffs.org/blog/building-a-psion-emulator "\"16 Shades of Grey\" — Building a Psion/EPOC32 Emulator"], 27 December 2019. Source for the CL-PS7110 / ARM710a identification on the Series 5, the Windermere / ARM710T identification on the 5mx, and the ETNA CompactFlash controller.</ref>
! !! Series 5 (1997) !! Series 5mx (1999)
|-
| '''Processor''' || '''ARM710a''' core in a '''Cirrus Logic CL-PS7110''' || '''ARM710T''' core in Psion's custom '''"Windermere"''' SoC
|-
| '''Clock''' || '''18.432 MHz''' || 36 MHz
|-
| '''RAM''' || 4 MB or 8 MB || 8 MB or 16 MB
|-
| '''Screen''' || 640 × 240 || 640 × 240, clearer panel
|-
| '''Screen ribbon''' || Series 5 type || '''A different part'''
|}

'''The screen ribbon cables are not the same''', which matters because that cable is the commonest failure on both machines.<ref name="r3uk">David Savery, [https://www.r3uk.com/index.php/tech-tips/34-disassembly-guides/9-psion-series-5mx-disassembly-and-screen-cable-repair "Psion Series 5MX disassembly and screen cable repair"], R3UK, 2004. Source for the screen ribbon failure mechanism and the statement that the 5mx uses a different screen ribbon from the Series 5.</ref>

== Architecture ==

The Series 5 is the first Psion product to use the '''ERA architecture''' around the ARM 7100. It is built as a '''main PCB and a ROM daughter PCB'''.<ref name="sm" />

=== Clocks ===

The CPU's main clock input is '''3.6864 MHz ±50 ppm''' from crystal X2 in fundamental mode, '''multiplied internally by five to 18.432 MHz''' (54.2535 ns). An expansion clock at that frequency is output from the ARM 7100 and used by the '''CompactFlash interface device, ASIC12 (IC2)'''.<ref name="sm" />

That CompactFlash controller is the part the developer and Linux-porting community know as '''ETNA''' — a bespoke, essentially undocumented Psion device present in both the Series 5 and the 5mx.<ref name="wuffs" /> The service manual and the community use different names; no document states in so many words that they are the same part, but they occupy the same role.

=== Reset ===

Two distinct resets, and knowing which is which matters when a machine misbehaves:<ref name="sm" />

* '''Power-On Reset (cold reset)''' — generated by a '''Ricoh RN5VLR20AA''' open-drain voltage detector (IC4) when VDD crosses a threshold set to '''2.0 V ± 2.5 %'''. An RC network stretches the low state to give the ARM 7100 time to reset. '''A cold reset erases everything held in volatile storage''' and indicates that all power was lost and re-applied.
* '''User Reset (warm reset)''' — a switch that '''forms part of the lithium backup battery's negative contact''', normally reachable only by opening the backup battery cover and using a pointed instrument. Held inactive high by pull-up R1, with a small capacitor C113 providing noise bypass to protect against inadvertent resets during ESD events. '''All user data should survive a warm reset.'''

=== Display and digitiser ===

The LCD is a '''640 × 240 passive-matrix module, normally-white'''. All data, clock and synchronisation signals come from the ARM 7100.<ref name="sm" />

A '''separate passive resistive digitiser''' is assembled over it: a glass lower plate and a hardened plastic top plate, resistive ink printed on the inner faces, four electrical connections sensing resistance across the X and Y axes, and the two conductive faces held apart by '''very small bumps moulded into the plastic member'''. It connects by a '''22-way flat flexible cable'''.<ref name="sm" />

The LCD's supply rails '''must be enabled and disabled in a defined sequence''' so that no residual DC is ever left across the panel — DC causes the liquid crystal to drift and eventually damages its polarisation irreversibly. The logic supply VLL comes from an ordinary port output because it needs only about 2 mA; the '''main high-voltage supply is an ARM 7100-controlled boost switched-mode supply with a 4-bit DAC acting as a variable resistor in the feedback path'''.<ref name="sm" />

=== Keyboard ===

'''53 keys''' in a conventional QWERTY arrangement, on a separate switch matrix assembly that slides out as the screen opens. It connects to the main PCB by a '''22-way flat flexible cable in a 22-way ZIF connector, of which only 20 ways carry keys''' — '''the outside pins are grounded to give the keyboard membrane a ground ring for ESD protection'''.<ref name="sm" />

=== ROM board options ===

Psion built three ROM daughter boards:<ref name="sm" />

{| class="wikitable styled-table" style="width:60%; text-align:left;"
! Board !! Devices
|-
| ROM Board 01 || 3 × Flash devices
|-
| ROM Board 02 || 1 × ROM device and 1 × Flash device
|-
| ROM Board 03 || 2 × ROM devices
|}

'''Intermittent faults can be caused by dry or faulty joints on the daughter PCB''', and Psion suggest swapping it early in diagnosis as a quick test. Any replacement '''must be the same OS build number and language''', checkable with '''Ctrl+H''' in the System screen.<ref name="sm" />

=== Standby current ===

Measured with the processor asleep at 2.75 V:<ref name="sm" />

{| class="wikitable styled-table" style="width:50%; text-align:left;"
! Model !! Standby current
|-
| 4 MB || 1.50 mA
|-
| 8 MB || 2.10 mA
|}

== Build variants ==

Psion identified each build by part number, RAM size and language — 22 options in all, from '''2900-0003-01''' (4 MB English) through American, French, German, Italian, Spanish, Swedish, Norwegian, Danish and Finnish variants.<ref name="sm" /> The part number is set into the machine's serial EEPROM at Final Test, and '''once a unit has passed, that EEPROM is locked'''.<ref name="sm" />

== "Protea" ==

Psion's internal project name for the Series 5 appears throughout the service manual's own artwork and test equipment: the final test lead is labelled '''PROTEA_TEST_LEAD''' and the dummy battery '''DUMMY PROTEA BATTERY'''.<ref name="sm" />

== Documentation on this wiki ==

* '''[[Psion Series 5 Service Manual]]''' — Psion's own 46-page manual: circuit description, exploded views with part numbers for every moulding, screw and spring, spares kits, the full disassembly and reassembly procedure, and the Final Test '''Fail Ticket fault codes'''.

== General maintenance ==
{{Main|Psion Series 5 General Maintenance}}

== Troubleshooting ==
{{Main|Psion Series 5 Troubleshooting Guide}}

== Screen cable and hinge repair ==
{{Main|Psion Series 5 Hinge Cable Repair}}

== See also ==

* [[Psion Series 5mx]] · [[Psion Series 5mx Pro]] · [[Psion Revo]]
* [[Psion Series 3c]] — the SIBO machine the Series 5 replaced
* [[Battery Refurbishment]]

== References ==

<references />

{{Navbox-Psion}}

[[Category:Psion]]
[[Category:Home Computers]]

Psion Series 5 - Revision history

Josh: Remove the Category:Home Computers link — the category has no page and renders as a red link

Josh: Create Psion page set: researched from Psion manuals, service documentation and community repair sources