Acorn Pocket Book II

OEM Re-badged version of a Psion 3A.

Acorn Pocket Book II General Overview

Note: Where they are available, higher resolution versions of images on this page can be accessed by clicking on them.

Acorn Pocket Book II System Specification:

Manufacturer: Psion, for Acorn Computers.

Model: Pocket Book II AHB05.

Launch date: 1994.

Production date of this machine: Not known.

Price: 240.88 for the system unit itself as of December 1995 - Equivalent to approximately 500 at time of writing.

CPU: NEC V30 clocked at 7.68MHz.

Memory: ROM: 1Mb.  RAM: 256K.

Display: 5.25" (13.4cm) reflective greyscale LCD, three shades of grey. 480 x 160 pixel resolution.  No backlight.

Storage: 256K internal battery backed RAM-Disc - Up to two plug in proprietary solid state memory modules could also be fitted at up to 1Mb each.

Expansion: 2x proprietary expansion slots.

External ports: DC input jack (centre negative), proprietary serial bus connector.

Power requirements: 3V DC via 2x AA batteries or 9V DC adapter (model number AHA35).  CR1620 3V Lithium coin cell for memory backup.

Weight: 275g including batteries (9.7oz).

Note on model number disambiguation:

There are actually three versions of the Pocket Book II, these differ only in the amount of RAM installed.  For clarity these are listed below:

[] AHB05 - 256K (as featured on this page).

[] AHB06 - 512K.

[] AHB07 - 1Mb.

There is a small label to the upper right of the keyboard which shows how much memory is installed.

Acorn Pocket Book II Memory capacity badge above keyboard

It is hard to overstate how far ahead of the game in many aspects and how far outside the box Acorn Computers were throughout the 1980s and into the early 90s.  Despite being a relatively small British computer company that if you're in the US you've entirely likely never even heard of, they played a massive role in the education and home computer market in the UK, and left a legacy which spans the globe even to this day.  They were the ones behind the ARM microprocessor which powers a very large portion of the mobile electronic devices to this day.  ARM when it was launched stood for Acorn Risc Machine.  Though the word "Acorn" has been replaced with "Advanced" in recent years.

Acorn's biggest single or at least most well known claim to fame was producing the machine which was launched as the BBC Micro and its descendents.  This was produced (as the name would suggest) in conjunction with the BBC who produced a television series aimed at improving computer literacy in the early 80s.  A large portion of that project was also the aim to get the machines into every single primary and secondary school in the UK - a task which as far as I know they pretty much managed.  If you were born in the UK in the 80s, you've almost certainly used one of these.

Acorn BBC Micro Model B General overview

While it was an extremely accomplished machine, Acorn didn't just sit on their laurels and were quick to start work on its successor.  Something which would still be very much at home in the educational sector, but also to compete more directly with the ever growing market share of the IBM PC and compatibles.  This is where their outlook on things really showed - They deemed that the system architectures being used by all the big players at the time to be inadequate for their purposes.  So they designed their own.  I'm not talking about using existing components and rearranging them, no they came up with their own CPU, video controller, memory manager, system timers, everything...and of course the operating system itself.  Oh, and this was to be a fully 32-bit machine from the outset.  The result was what became known as the Archimedes line, and was a truly fantastic piece of engineering.  These machines were fitted with their ARM CPU, and due to the efficiencies afforded it proved massively more powerful than you would expect to look at the raw numbers in terms of clock speeds and memory installed.  Between the RISC based CPU and having the operating system - and we're talking a fully GUI based OS here, Risc OS is something which itself deserves its own page here - stored in ROM, the performance offered really was quite extraordinary.  I'd say it's a pretty good bet that the Archimedes range is the most capable family of computers you've never heard of.  This effect was turned up to 11 in the mid 90s when they launched the Risc PC - a heavily beefed up version of the original vision boasting Pentium-esque clock speeds and a construction which made the computer by the standards of the time seemingly endlessly expandable.  This was a machine which offered an expansion card with an 80486 CPU on it, allowing you to run normal PC software in a window on the Risc OS desktop - at very nearly full speed, and sharing all of the resources of the host machine pretty seamlessly.  While that doesn't maybe sound like much in 2023 - it was one heck of a party trick in the mid to late 90s. 

Of course Acorn themselves didn't survive the 90s as was true of so many pioneering companies in computing.  If a few business decisions had swung a different way and Acorn having been rather better at making the world actually know their products existed and what they were capable of it's entirely likely they'd still be with us today.  They had designed and had pretty much ready to launch an even more powerful machine to replace the Risc PC, but sadly the money ran out and the company folded before more than a handful of prototype machines were made - There being only one known working survivor as far as I'm aware which lives in the Centre for Computing History in Cambridge.  A fitting place for it to end up given Acorn's roots in the city.

While the company as a whole folded, the hardware side split off into ARM - who evidence suggests have done quite well for themselves!  Believe it or not, the software side is indeed still being developed too by RISC OS Ltd.

Rewinding to the dawn of the 90s however, Acorn had a solid base of computers in the schools but had always wanted to go further with that.  One of their goals had been to be able to get a computing device into the hands of every student.  Obviously this would not be a fully featured machine like an Archimedes as the costs would have simply been prohibitive.  However a portable machine with a few basic but carefully considered functions might have been more viable.  Acorn were quick to spot that the Psion's model 3 PDA was pretty much exactly the machine they had in mind, so set up a partnership to produce Acorn branded versions of the machines.  The changes were purely branding and some tweaks to the pre-loaded software, the actual underlying hardware was completely unchanged.  A couple of years later when Psion launched the 3A, the Acorn Pocket Book also got an upgrade with the 3A re-badged as the Pocket Book II - the machine we have featured on this page.

While their vision of one of these machines being handed out to every student clearly were never realised, they (at least in my area) did seem to pop up fairly frequently in the school classroom in the late 90s, particularly in the science departments where their graphing and data logging functions were particularly useful.

While they were available to the general public I don't believe the Pocket Book or Pocket Book II ever really made any headway in the consumer market, as buyers would more likely just buy the Psion version - a name already synonymous with portable computing by that time.

The Pocket Book wasn't Acorn's only foray into the field of portable computing either.  In 1992 they launched the A4, essentially an A5000 shrunk down to fit into a laptop form factor (yes it's more complicated than that really - but without going into detail that's a very broad explanation).  However at least to me this always struck me as something more of a technical demonstration to show what they could do, as the price tag (1599 or discounted to 1399 for schools) always meant that it was going to struggle to gain a huge acceptance in the educational market, and the mainstream laptop market at the time was already competitive enough that there really wasn't room for a product from a relatively unknown company, running a completely proprietary operating system to make any impact, no matter how capable it may be on its own merits...and it feels to me that Acorn must surely have known that.  With this in mind, predictably the A4 never really took off, and as such is quite a rare and collectable machine today.  One that's very much on my wish list as a long time Acorn fan - but I've yet to find one at a price that I can justify.

The Pocket Book was never intended to be a replacement for a desktop computer (whether it be a PC compatible, Mac, or Acorn), but a companion to it.  Psion had really figured out the formula pretty well in how to make a genuinely useful tool which allowed you to view documents on the go (there were tools included to convert to a number of popular file formats), in theory make edits - though you'd not really want to be doing too much with the inbuilt keyboard on this, and had a reasonably comprehensive calendar/diary program built in.  Basically an early version of the setup that Palm made work very well for them from the late 90s through to around 2010 when the rise of smart phones finally killed them off.  Well...killed Palm off as a company anyway - the smart phone basically just absorbed the functionality of the PDA.  The (relatively) seamless integration via web/cloud based services between a smart phone and any PC irrespective of the operating system really is just an evolution of the idea which started with PDAs in the 90s.

We'll dig into the software a little later, but let's take a look at the device itself first.

General overview of an Acorn Pocket Book II with case closed viewed from the right

General overview of an Acorn Pocket Book II with case closed viewed from the left

It's a smart looking little thing, which exudes an air of quality with its slightly mottled grey finish and bright chrome badging.

Detail of badging on an Acorn Pocket Book II

One of the things I remember being quite surprised about when I first picked one of these up was just how light weight it is - only 275g, and that's including the batteries. 

The front of the device features a couple of moulded ridges to assist in opening the display.  There is no latch, but it does close pretty positively so is unlikely to be opened unintentionally.

General overview of the front of an Acorn Pocket Book II

The left hand side has the 6-pin serial interface connector towards the rear, and a fold out cover for the "A" expansion slot.

General overview of left hand side of an Acorn Pocket Book II, showing proprietary serial port connector to the rear

The rear of the machine initially appears devoid of features aside from two rubber feet which don't look to be pointing in a useful direction.  However the battery cover is actually there, surprisingly well hidden between the screen hinges.

General overview of rear of an Acorn Pocket Book II

A note on the batteries as well...Even back in the early 90s there was quite a trend for mobile devices to use obscure batteries.  Psion eschewed this approach with most of their popular models, opting for conventional AA cells.  Making the decision that having cheaply and readily replaceable cells was a greater quality of life priority than total run time or maybe saving a bit of weight.  Battery life is somewhere around the 60-80 hour mark, which on a device like this would likely stretch a decent ways.  There is a separate lithium coin cell which serves to maintain data in the memory and the clock while the main batteries are changed or for a period of time if they are discharged.

Memory backup battery hidden behind "B" expansion slot cover on an Acorn Pocket Book II

Those rubber feet actually are useful, as the rear section of the machine hinges down as the screen is opened as shown below.

Movement sequence of screen hinge as an Acorn Pocket Book II is opened

The right hand side like it's opposite contains a single port and a hinged cover for an expansion slot, this one labelled "B" - these letters matching  the drive letters reported by the OS if a memory expansion is inserted in the respective slots.  This side of the machine also contains a small barrel jack for the (centre negative) 9V DC input.

General overview of right hand side of an Acorn Pocket Book II showing the DC input jack towards the rear of the machine

Here's a photo showing all of the covers open/removed.

Underside of an Acorn Pocket Book II with all covers open/removed

The underside features markings for the various compartments and the prerequisite standard approval text around a centrally mounted speaker.

Detail of text surrounding speaker on underside of an Acorn Pocket Book II

Opening up the clamshell reveals a usefully large screen and keyboard.  There are no massive oddities to the keyboard layout either which is always a pleasant surprise on smaller mobile devices.

The display surround features quite attractive looking gloss silk-screened Acorn Pocket Book II branding.  Being glossy makes this stand out particularly against the matte finish of the case.

Maker's branding above the display on an Acorn Pocket Book II

Acorn Pocket Book II branding shown above the display

To get around the limitations of only having 58 physical keys, there are some additional control and special characters which are accessed by pressing the Acorn badged key to the lower left, these are denoted by green silk screened legends above the keys.

Detail of keyboard layout (including shortcut keys above main keyboard) on an Acorn Pocket Book II

Between the keyboard and display there is a bank of eight touch sensitive shortcut buttons - which sadly don't currently work on my machine, presumably due to failure of the ribbon cable connecting it to the motherboard.  These give direct access to the main device functions without needing to use the keyboard, and a shortcut to return to the desktop.

Just above and to the left of the escape key there's a small hole in the keyboard surround.  This conceals the reset button to reboot the device if necessary.

The keyboard isn't exactly something you'd want to be trying to touch-type on but is entirely usable.  There's very little by way of tactile feedback, though there is a software generated "click" that accompanies each key press to help out a little in that regard.  It's definitely far, far from the worst keyboard I've ever come across on a device like this, but isn't anywhere near as user friendly as the excellent keyboard on the Psion Series 5 for example.  Though that's a tough yardstick to compare to given it's honestly the only machine this sort of size which I can honestly say it's entirely possible to with a little acclimatisation touch type on reasonably comfortably.  Here's a comparison of the keyboard on the Pocket Book II and a Psion Series 5.  The Series 5 of course being the successor to the machine the Pocket Book II shared its platform with (no, there was no Series 4) dating from 1997 so some comparisons between the two machines make sense.  The Series 5 surely has to class as one of the best designed computers of its type ever to have been made.

Acorn Pocket Book II (left) shown next to a Psion Series 5 (right).

My example apparently decided that it was camera shy and the screen (which has always been a little twitchy on this example) quit working when I took it out to take the above photo.  Failure of the ribbon cable to the display is a common problem on the Series 5 and kits do exist to affect a repair - it is quite a fiddly job though which involves taking apart pretty much the whole machine, and it wasn't really designed to come apart again once it was together!

Two small rubber buffers below the keyboard cushion the interface between screen surround and keyboard when the device it closed.

The display is a reasonably decent effort for the time, with the ability to show black, white and a mid-tone grey.  The viewing angle isn't bad at all and it's a nice sharp display without any banding or smearing issues.  The single biggest gripe with it is the lack of any form of backlight which can at times be an issue in poorly lit areas.  Being honest though it really isn't bad.  I think a lot of my criticism comes simply from how spoiled we are these days with modern TFT and OLED displays!  It really isn't a chore to look at, and the 1/2 second or so response time really isn't a problem for the type of applications this thing was designed for.  Equally the resolution of 480 x 160 pixels sounds trivial in this day of phones with 4K displays, but is absolutely adequate to provide clear, well formed fonts and graphics on screen.  I really do find myself questioning the need for such high resolutions as we have nowadays on smaller portable displays...Sure, a 4K display makes perfect sense when it's 20" and you're going to be either watching movies or playing games on it...but something a couple of inches across?  Do we really NEED that pixel density?

The display uses what's referred to as "time domain greyscale" meaning that the actual drive circuitry can't actually produce grey - grey is simply a pixel that's being turned on/off rapidly with the duty cycle such that it's "black" for about half the time, so the net result as far as the user is concerned is grey.  This does mean that under certain lighting conditions there is a little flicker visible.  While three colours doesn't sound like much, it's perfectly sufficient for what this device was designed for, and with a bit of inventive handling of dithering could produce some pretty decent looking results - such as the system's "about" screen.

Display of an Acorn Pocket Book II showing the System Information Screen

This actually probably looks a good deal better in person simply because you're most likely looking at it on a screen considerably larger than the original, so the individual pixels and the dithering are far more visible.  At normal viewing distances it looks far less blocky in person than it does on my computer screen.

Unlike the later Psion products such as the Series 5 which used ARM based processors, this uses an NEC V30 CPU.  Which if you're not familiar with 80s PC hardware you may well not have heard of before - but it's essentially a slightly upgraded clone of an Intel 8086 - so this is more PC-like under the hood than you might expect - at least at the CPU instruction and IO level anyway.  Pretty much all of the support circuitry you'd expect to see scattered around the motherboard and on expansion cards of an 8086 based PC is all rolled into one ASIC package (which also physically contains the CPU itself), with very little in the way of other hardware on the motherboard itself - basically just the power regulation, memory itself and a standalone chip which as best I can tell is handling audio encoding/decoding based on it having traces which look to head off towards the microphone.  The other side of the board has nothing to show aside from the keyboard matrix.

It really was quite an impressive feat managing to integrate so much of the system hardware into a single chip in the early 90s. 

Part of the beauty of both the Psion and Acorn badged versions of this machine were in the choice of bundled software it came with installed.  Rather than trying to emulate every piece of software on a full sized desktop machine, things were simplified into eleven applications.  Let's go through these - in the order they're shown on the device.

Their respective shortcut keys (where applicable) and icons are grouped together with the program information.


 Detail of the "Cards" shortcut key and application icon on an Acorn Pocket Book II

This is a pretty basic card-file style database program for storing data such as personal contact details.  The ability to sync this with software on your main computer is what gives this its real value I reckon as it would have meant that you could keep a pretty comprehensive phone book etc on you while on the move (remembering this was before the days of mobile phones, so a phone book was indeed a physical book).  It is searchable by any field, and its flexibility is helped by the ability to customise the field names.

An example of this application in use is shown below.

Screenshot of the "Cards" program running on an Acorn Pocket Book II


 Detail of the "Write" program shortcut key and program icon on an Acorn Pocket Book II

A simple WYSIWYG text editor.  This does support basic formatting features such as multiple fonts, bold, underline etc and luxuries such as a spell checker and thesaurus.  While you're not likely to have wanted to write a novel actually on the Pocket Book, the ability to view documents on it and make small changes was likely to be far more useful - something which could easily be done as the bundled PC software allowed many common file formats of the time to be exchanged with the Pocket Book.

An example screenshot of this application in use is shown below.

A screenshot showing the "Write" word processor application running on an Acorn Pocket Book II


Detail of the Schedule application shortcut key and application icon on an Acorn Pocket Book II

The name says it all really!  Emulating a paper diary, with support for views in page-per day/month/year, to do lists, recurring events such as anniversaries and user configurable to-do lists.  As with a lot of the programs, the ability of this to synchronise with your desktop machine would really have added to the usefulness of this back in its day.  We tend to take having a calendar we can access from anywhere on any device via services like Google Calendar for granted these days, but they simply didn't exist back in the early 90s - having an electronic one which you could physically plug in and sync across multiple devices was about as close as it got.

Example screenshots are shown below of the Schedule application in several display modes...

Per-Day view:

Schedule application on an Acorn Pocket Book II in "Per Day" view

Per-Week view:

Schedule Application running on an Acorn Pocket Book II showing the per-week view

Per-Year view:

Schedule application running on an Acorn Pocket Book II showing the per-year view

To-Do List view:

Schedule application running on an Acorn Pocket Book II showing the To-Do list view

Anniversary View:

Acorn Pocket Book II Schedule application shown in Anniversary View Mode

List view - shows a simple text list of any appointments on a given day.

Acorn Pocket Book II Schedule Application in List View


Detail of the "Time" shortcut key and application icon on an Acorn Pocket Book II

A pretty simple alarm clock program.  It does actually have deeper functionality though in that this program always runs in the background as it also handles the actual system timers.  This also means that it's the only pre-installed program which doesn't have an exit option in the menus, making it impossible to exit without a soft-reset if the shortcut bar doesn't work as on my machine.  The fact that this program is running is why its text is shown in bold on the on-screen icon.  If you were to stop this program the entire system would lock up requiring a hard reset to recover.

An example screenshot of this application is shown below.

Acorn Pocket Book II Showing the Time application (with no alarms set)



Detail of the World application shortcut key and application icon on an Acorn Pocket Book II

A graphical world clock, showing additional information such as distance from your set home time zone, telephone area dialling codes and what country other time zone cities are in.  It is possible to edit cities in the list and add additional ones.

An example screenshot of this application in use is shown below.

Screenshot of an Acorn Pocket Book II showing the World Clock application running

Note: The discolouration shown on the "b" in Cambridge and just below the UK on the map are due to on-screen animation in those areas causing issues with the camera.  The B is flashing as I'd typed in "Camb" to search for Cambridge, and there is a flashing crosshair showing its location on the map.


Detail of "Calc" shortcut key and application icon on an Acorn Pocket Book II

Again one of those programs which does what it says on the tin.  It's a calculator.  A little awkward to use given the keyboard layout, but reasonably powerful with support for trig functions and the ability to load in OPL programs and create lists.

Output is shown on a receipt roll type display which tracks calculations as they are done.

An Acorn Pocket Book II showing the Caluclator Application


Detail of the "Abacus" application shortcut key and icon on an Acorn Pocket Book II

The last of the applications with a dedicated shortcut key.

A basic but functional spreadsheet program which even includes some basic graphing capabilities.  I imagine this would probably have been more useful to view pre-existing content created on a desktop machine rather than being used directly to put together any complex sheets.

While the functionality seems very rudimentary in 2023, it probably would have done what the vast majority of users would have wanted it to while on the move back in 1994.

An example screenshot showing the spreadsheet data view:

An Acorn Pocket Book II showing the Abacus spreadsheet program in Normal View

Then the same data as shown above in the first column, in graph view.

An Acorn Pocket Book II showing the Abacus Application in graph view

Bar, stacked bar, line, pie and scatter chart types are available.


Detail of the application icon of the "Spell" application on an Acorn Pocket Book II

A standalone spell checker, thesaurus and (admittedly somewhat limited) dictionary, also including an anagram and crossword solver.  This can be invoked from within the Write application as well or used on its own.

An example screen shot of this application is shown below.

Speller and Thesaurus application running on an Acorn Pocket Book II

As tended to be the case for programs like this on even a full desktop computer in the period though its usefulness is very limited because of the tiny inbuilt dictionary.  Asking it to look up "computer" for instance doesn't even provide a direct match, instead jumping to "compute" which is the nearest that it could manage.

Speller application on an Acorn Pocket Book II showing an example word being looked up

Attempting to include this functionality when you're trying to fit all of the operating system, applications AND a dictionary within the available 1Mb of ROM was always going to be a bit ambitious.


Detail of the "Record" audio recorder application icon on an Acorn Pocket Book II

An audio record/playback program.  An expansion SSD really does need to be installed for this to be able to provide any useful amount of recording space though.  On this 256K hardware without one fitted it will only allow two seconds of audio to be recorded!

The voice recorder application on an Acorn Pocket Book II


Detail of the "Plotter" application icon on an Acorn Pocket Book II

This is one of the programs which we probably used the most when I came across these machines in school - and was software unique to the Acorn badged version of the device.  This allows for data captured (or pre-existing data from another list) to be plotted graphically.  Direct mathematical functions can also be plotted as well as on a graphing calculator.  It's quite slow, but does work.

The other shortcoming with this program is that it does not automatically scale the graphing axis, so you need to set those up with reasonable value before you will get any sensible looking output from it.

An example screenshot from the Plotter application on an Acorn Pocket Book II


Detail of the "Program" OPL programming application icon on an Acorn Pocket Book II

The ace up the sleeve of both this and it's Psion badged brother for power users is direct access to a structured somewhat BASIC-like programming language.  Probably the biggest shortcoming in this exact implementation of it is the lack of any direct support for predefined graphics (such as being able to draw lines, circles, arcs etc using a single command).  Of course there were various ways around this, as demonstrated by quite a number of games that make full use of the display, just requiring a bit more work from the programmer.  OPL continued to be supported on Psion products for some time, though was largely supplanted by more modern languages such as Python in mainstream use in the early 2000s.  An open-source variant did emerge following Psion's exit from the market, though the Sourceforge page looks to have last been updated in mid 2006 (checked in July 2023) - so it doesn't look to be exactly bristling with current activity.

An example of the screen you are presented with when starting this program is shown below - Afraid I don't know the first thing about programming in OPL, so haven't even attempted to write an example here!

An example screenshot of a new program in the OPL Program application on an Acorn Pocket Book II

When I picked up this unit it didn't come with any of the PC interface hardware, so I can't demonstrate any of that functionality at this time.  Hopefully somewhere down the road I will find the link cable so can delve into that to show how it would have worked.  I've got the necessary hardware to demonstrate both the IBM PC and Acorn versions of this, though I'm not so sure about the Apple version.  I'll look into that in more detail once I find a link cable.

Unlike the Psion Series 5 which launched a few years later, the expansion slots on the Pocket Book II use a proprietary connector, so you do need the correct Acorn (or Psion) cartridges to use them.  A shame as just being able to plug a Compact Flash card into a card reader and transfer software/data to and from a modern PC is nice and simple.  No such option exists for the Pocket Book II, you really do need the interface cable.

It's an interesting little machine from the era when portable computing was really starting to come into its own.  Psion really were on the ball for a good few years with the 3 and Series 5 machines, having come up with a product which was a pretty perfect companion to a desktop machine for someone on the go.  Sadly I never had the opportunity to use one of these in period, but I did have a Palm Tungsten in the early 2000s, which I used heavily right up until the point at which I got my first smart phone somewhere around 2010.  These machines really would have filled exactly the same niche only a few years earlier.

Did this Acorn badged version of the Psion 3 and 3A really need to exist?  Strictly speaking probably not.  I can see what Acorn were going for though and it was a worthy goal, but no matter what they did this was always going to be too expensive to be rolled out to the extent they would have liked - and my take on that is that that would always have been the case right up until the point where the vast majority of students already HAD a computing device on their person anyway due to the proliferation of smart phones.  That's not even an indication of how the relative price of technology has fallen I feel but more an indication of how much more entwined with our lives it has become, so that cost is seen as more reasonably justifiable.  You do have to wonder, well polished that they may have looked, whether the money spent on the Pocket Book and A4 projects really may have been better spent elsewhere rather than trying to muscle in on the hyper-competitive and already crowded mobile computing market of the early 90s.  Of course without access to a time machine and/or the ability to look into parallel universes, we'll never really know what might have been and whether that might have had any impact on Acorn's long term prospects.


It's an interesting little machine though, and really was a very accomplished package for its time.  As a lifelong Acorn fan I'm definitely glad to have one in the collection.

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Page created on 28th August 2023.