Editing Psion Series 3c

{{Infobox computer
| name         = Psion Series 3c
| image        = [[File:Psion Series 3c.jpg|250px]]
| caption      = A Psion Series 3c, open
| developer    = Psion PLC
| manufacturer = Psion PLC
| type         = Clamshell palmtop / PDA
| release_date = 1996
| discontinued = 1998
| cpu          = NEC V30H @ 7.68 MHz, in Psion's ASIC9
| memory       = 1 MB ROM; 1 MB or 2 MB RAM
| storage      = Two internal Solid State Disk (SSD) slots
| display      = 480 × 160 monochrome LCD; backlit on later models
| sound        = Membrane speaker, built-in microphone, 12-bit sound recording
| dimensions   = 165 mm × 85 mm × 22 mm
| weight       = 275 g including batteries
| os           = EPOC16 (SIBO), with OPL
| predecessor  = [[Psion Series 3a]]
| successor    = [[Psion Series 3mx]]
| model        = There was never a Series 3b
}}
The '''Psion Series 3c''' of 1996 is a refined [[Psion Series 3a|Series 3a]]: same processor, same screen resolution, but with an '''infrared port''', a '''changed serial port''', '''revised built-in software''' and, on later machines, a '''backlight'''. Psion never released a Series 3b.<ref name="wp3">[https://en.wikipedia.org/wiki/Psion_Series_3 "Psion Series 3"], Wikipedia. Source for the model history, the absence of a 3b, the infrared port, the changed serial port, the case redesign, the backlight, the RAM options, the Easter egg and the documented clamshell problems.</ref>

== What changed from the 3a ==

{| class="wikitable styled-table" style="width:70%; text-align:left;"
|+'''Series 3a → Series 3c'''<ref name="wp3" /><ref name="spec">[https://www.psion.netogram.com/psionspecifications.html "Psion specifications"], netogram.com. Source for the comparative specifications including serial speed, ROM and RAM sizes, keyboard button counts and backlight availability.</ref>
! Change !! Detail
|-
| '''Infrared port''' || Added, and visible on the case
|-
| '''Serial port''' || '''Changed''' — the 3c uses the same arrangement as the [[Psion Siena|Siena]], and a serial cable for direct connection to a Windows PC was supplied. '''Travel Modem connections differ between 3/3a and 3c/3mx.'''
|-
| '''Serial speed''' || Raised to 56,400 bit/s
|-
| '''Case''' || Redesigned: badge moved centrally on the lid, fewer undulations, '''matte dark grey painted finish'''
|-
| '''Backlight''' || Fitted to later models — mainly, though not only, the US 2 MB machines
|-
| '''RAM''' || 1 MB or 2 MB only
|-
| '''Application buttons''' || '''9''' reprogrammable buttons, against the 3a's 8
|-
| '''Expansion''' || Two internal SSDs plus an external PC-Card option
|-
| '''Software''' || Several modifications to the built-in applications
|}

Everything else — the '''V30H at 7.68 MHz inside ASIC9''', the 480 × 160 screen with its grey plane, the microphone and 12-bit sound recording, the 58-key keyboard, 2 × AA cells and the '''CR1620''' backup cell — is as the 3a.<ref name="spec" /><ref name="wp3" />

For the architecture itself — ASIC9, the bank-switched memory, the hardware 32-bit RTC, the power states and the supply rails — see [[Psion Series 3a]].

== The SSD door sensing ==

This is the one internal difference that matters for repair.

The 3c senses the state of its SSD slot doors using '''a set of PCB tracks and a small metal connector on the slot door hinge'''. The later [[Psion Series 3mx|3mx]] replaced that with '''a pair of angled microswitches''' — which is why the 3mx has a characteristic broken-switch fault that the 3c does not.<ref name="rc3mx">Richard Zealley, [https://www.retrocoding.uk/psion-3mx-ssd-microswitch-repair/ "Psion Series 3mx SSD door microswitch repair"], Retro Coding, 25 May 2020. Source for the difference between the 3c's door-sensing tracks and the 3mx's microswitches.</ref>

On a 3c that will not see an SSD, '''clean the tracks and the metal door contact''' before suspecting anything else.

== The sticky case ==

The 3c's redesigned case carries a '''rubberised soft-touch coating''', and with age that coating '''degrades into something resembling glue'''. It is one of the first things a collector notices about a 3c that has been in a drawer since the 1990s.<ref name="sticky">Community discussion of the Psion 3c sticky-case problem on comp.sys.psion.misc, together with established soft-touch coating restoration practice. Source for the degradation of the 3c's rubberised finish and the isopropyl alcohol stripping method and its cautions.</ref>

It is fixable — see [[Psion Series 3c General Maintenance]].

== Easter egg ==

The 3c and the later [[Psion Series 3mx|3mx]] contain an Easter egg: a hidden melody and credits screen.<ref name="wp3" />

== Known problems ==

As with the rest of the family: '''hinge breakage''', '''button bar failure''', '''screen cable deterioration''' producing vertical lines,<ref name="wp3" /> and the '''battery lead'''. Add to those the '''sticky case coating''', which is specific to the 3c.

== General maintenance ==
{{Main|Psion Series 3c General Maintenance}}

== Troubleshooting ==
{{Main|Psion Series 3c Troubleshooting Guide}}

== Hinge repair ==
{{Main|Psion Series 3c Hinge Repair}}

== See also ==

* [[Psion Series 3]] · [[Psion Series 3a]] · [[Psion Series 3mx]] · [[Psion Siena]]
* [[Battery Refurbishment]]

== References ==

<references />

{{Navbox-Psion}}

[[Category:Psion]]