Editing Psion Revo

{{Infobox computer
| name         = Psion Revo
| image        = [[File:Psion Revo.jpg|250px]]
| caption      = A Psion Revo
| developer    = Psion Teklogix
| manufacturer = Psion Teklogix
| type         = Clamshell palmtop / PDA
| release_date = November 1999
| discontinued = 2003
| cpu          = ARM710T @ 36 MHz
| memory       = 8 MB ROM; 8 MB RAM
| storage      = Internal RAM disk only — '''no CompactFlash slot'''
| display      = 480 × 160 monochrome LCD, 16 greyscales, resistive touchscreen, '''no backlight'''
| sound        = Speaker
| dimensions   = 157 mm × 79 mm × 17 mm
| weight       = 200 g
| os           = Symbian (EPOC32) Release 5
| predecessor  = [[Psion Series 5mx]]
| successor    = Conan (prototype, never released)
| model        = Rebadged as the Diamond Mako; Chinese-market 618C and 618S
}}
The '''Psion Revo''', launched in November 1999, is the small, light EPOC machine: the same '''36 MHz ARM710T''' and the same software as the [[Psion Series 5mx|Series 5mx]], in a case '''157 × 79 × 17 mm''' weighing '''200 g''' against the 5mx's 354 g.<ref name="wprevo">[https://en.wikipedia.org/wiki/Psion_Revo "Psion Revo"], Wikipedia. Source for the launch date and lifespan, dimensions and weight, the processor and memory, the omissions relative to the 5mx, the Revo Plus, the Diamond Mako and Chinese-market rebadges, the Conan prototype, the OpenPsion and Revol projects, and the entire battery and charging discussion.</ref>

The weight came out of the specification. Relative to the Series 5 and 5mx the Revo has a '''smaller screen''' (480 × 160 rather than 640 × 240), '''no flash-card slot''' and '''no backlight''' — and, most consequentially for anyone owning one today, '''no user-replaceable batteries'''.<ref name="wprevo" />

== Hardware ==

{| class="wikitable styled-table" style="width:70%; text-align:left;"
|+'''Psion Revo specification'''<ref name="wprevo" /><ref name="spec">[https://www.psion.netogram.com/psionspecifications.html "Psion 3mx, Psion 5, Psion 5mx, Psion Revo and Psion Revo Plus specifications"], netogram.com. Source for the ROM and RAM sizes, interfaces, docking station, average run time and power adapter rating.</ref>
! Item !! Specification
|-
| '''Processor''' || '''ARM710T''' at '''36 MHz''' — the same part as the Series 5mx
|-
| '''ROM''' || 8 MB
|-
| '''RAM''' || '''8 MB''' (16 MB on the [[Psion Revo Plus|Revo Plus]])
|-
| '''Display''' || 480 × 160, 16 greyscales, resistive touchscreen. '''No backlight.'''
|-
| '''Storage''' || Internal RAM disk. '''No CompactFlash or other card slot.'''
|-
| '''Interfaces''' || IrDA, and RS-232 on a 9-pin D-sub, at up to 115,200 bit/s
|-
| '''Connectivity''' || Docking station
|-
| '''Power''' || '''Two internal, non-user-replaceable NiMH AAA cells, 700 mAh''', about 14 hours
|-
| '''Mains adapter''' || 100–240 V AC ±10 %, 50/60 Hz
|-
| '''Size and weight''' || 157 × 79 × 17 mm, 200 g
|-
| '''Operating system''' || Symbian (EPOC32) Release 5
|}

It is '''software compatible with the 5mx''' and, like it, carries a small suite of office and communications applications in ROM. Extra software is installed from a desktop computer through the docking station.<ref name="wprevo" />

== ⚠️ The batteries ==

'''The Revo was notorious for battery and charging problems''', and this is the single most important thing to know about the machine.<ref name="wprevo" />

Where the 5mx takes two ordinary AA cells you can change in a corner shop, '''the Revo's two 700 mAh NiMH AAA cells are soldered to a connector and sealed inside the case, under the nameplate'''. Twenty-five years on, essentially every surviving Revo needs them replaced.<ref name="wprevo" /><ref name="r3uk">David Savery, [https://www.r3uk.com/index.php/tech-tips/34-disassembly-guides/3-psion-revodiamond-mako-disassembly-and-battery-replacement "Psion Revo/Diamond Mako Disassembly & Battery Replacement"], R3UK, 2004. Source for the disassembly and battery replacement procedure, the cell specification, the temperature sensor and the case microswitch.</ref>

Three specific behaviours are worth knowing before you touch one:

* '''Revos suffer from batteries coming loose and unplugging''' inside the case — a problem Psion '''fixed in the [[Psion Revo Plus|Revo Plus]]'''.<ref name="wprevo" />
* '''Use NiMH cells only.''' Because of the way the charging circuit works, nothing else is recommended.<ref name="wprevo" />
* '''Do not put a Revo on charge when the battery is already above about 80 %.''' The charge termination depends on sensing a thermal change around that level, and '''missing it can and does lead to overcharging'''.<ref name="wprevo" />

The full procedure, including the recalibration charge that has to follow it, is on the '''[[Psion Revo Battery Replacement]]''' page.

== Variants and relatives ==

{| class="wikitable styled-table" style="width:70%; text-align:left;"
|+'''The Revo family'''<ref name="wprevo" />
! Machine !! Difference
|-
| '''[[Psion Revo Plus]]''' || '''16 MB''' of RAM instead of 8 MB, a larger battery, and the loose-battery problem fixed
|-
| '''Diamond Mako''' || A [[Psion Revo Plus|Revo Plus]] rebadged by SONICblue for the United States and Canada
|-
| '''618C and 618S''' || Chinese-market Revos produced with Enfour, for traditional and simplified characters respectively
|-
| '''Conan''' || The unreleased successor. A third-generation PDA running '''EPOC Release 6''', intended to have '''Bluetooth and a backlight''' — although Bluetooth did not function in the development builds
|}

== The backlight that isn't ==

The Revo has no backlight, and there is a persistent story that the wiring for one was left in place. Pads marked '''EL+''' and '''EL−''' do exist under black tape on the screen PCB — but a voltmeter across them shows '''no reading, AC or DC''', with the unit on or with the Fn + Space sequence that works on a Series 5.<ref name="r3uk" />

'''Fitting a backlight to a Revo has not been shown to work.'''

== Linux ==

The '''OpenPsion''' project (formerly PsiLinux) ports Linux to the Revo, and '''Revol''' is an optimised version of OpenPsion specifically for it.<ref name="wprevo" />

== General maintenance ==
{{Main|Psion Revo General Maintenance}}

== Troubleshooting ==
{{Main|Psion Revo Troubleshooting Guide}}

== Battery replacement ==
{{Main|Psion Revo Battery Replacement}}

== See also ==

* [[Psion Revo Plus]] · [[Psion Series 5mx]] · [[Psion Series 5]]
* [[Psion Series 3mx]] — the SIBO machine the Revo replaced in the small-palmtop role
* '''[[Battery Refurbishment]]'''

== References ==

<references />

{{Navbox-Psion}}

[[Category:Psion]]