London RISC OS Show 2020

This is a transcript of the full talk I would have given at the 2020 Virtual London Show if I’d been organised enough to book a slot in time!

We’ve now been in our new premises for over a year but have been so busy we’ve still not opened some boxes yet!
Moving out of the shop which we’d leased for 36 years meant we had to sort out what they call the Dilapidations (Repairs and redecoration) on the building, the surveyor costed most, but not all, of the necessary work at over £66,000! There are still things to do but I’m hoping it will cost not much more than half that.
Jason joined us before Christmas and has been busy processing orders and adding items to our ebay shops. There have been many Acorn related things that we’ve had listed on our website for years, which when listed in one of our ebay shops sell quickly even when they cost more! Our two ebay shops are cje-micros and four-d-pi-shop

On a personal note at the end of last year I started a string of tests for Prostate cancer and after two biopsy’s they told me at the beginning of March it was cancerous but that they could cure me. I started hormone treatment straight away.
Then came lockdown and the government said only do essential travel so Andrew and Jason went on furlough, only for the government to then say Mail order businesses could continue. So I was left holding the fort and with most people then having more time for their hobbies I was kept very very busy. After six weeks Andrew returned and then with Jason back we were able to catch up with things just in time for me to have four weeks of Radiotherapy out of the county every weekday. My PSA is now very low so it is looking good though they will still do regular test for at least five years.
As many readers of this posting are going to be male and over 50 I would like to take this opportunity to urge you to have regular PSA tests, my oncologist told me that because my tumour was on the edge of the prostate it would have not caused any symptoms.

During lockdown many people have had a clear out of their old Acorn/RISC OS kit and we’ve had a dozen or so people either bring us or we’ve had collected anything from a single BBC to a van load of kit!

In the last year we’ve been developing/sourcing more RISC OS kit including:

Adjustable resolution USB optical mice 800,1200 & 1600 DPI as it is controlled by a small easily accessed button on the mouse it needs no software so it is RISC OS compatible. Ideal for CAD or Artwork: Variable DPI MOUSE

Sourcing more power switches for Phillips/Acorn CRT monitors: Monitor power switch a surprising number of people still want the full retro experience of CRT monitors!
Also for the retro market floppy disc cleaning discs are now very rare often selling for £30 or more so we now offer a two week hire. 5.25″ Cleaning disc , 3.5″ Cleaning disc and we even do a 3″ cleaning kit hire.

mSATA adaptor and drives suitable for use with IDEFS interfaces (tested and known working on ZIDEFS interfaces in a RiscPC and A4000) a brief test on an Acorn IDE bus worked but due to HForm problems, only if we’d formatted the drive on a RiscPC before hand.
Though with 16GB being the smallest we can buy new, it is a bit of overkill when one or four 512MB partitions are all you can use.

RapidO Ig: Special show deals a new case and better monitor compatibility.

With all three of the cases we used to use now being discontinued we have found a new nice compact, versatile reasonable priced case.
A few people reported problems with Monitor compatibility I am very pleased to say that ROOL have recently been able to tweak the video driver so that most LCD monitors now work.

More details and a Special offer price available here.

RaspberryRO 4

Following sterling work, most recently by Sprow, RISC OS now supports the Raspberry Pi 4 without having to fudge things.
So today we are pleased to announce the RaspberryRO 4 we’re also now offering after extensive research a new tower/desktop case which whilst compact still supports an optical drive, allows us to offer up to 10 USB ports (2 front, five rear and three internal) card reader and internal PSU.
We are offering 2, 4 and 8GB versions with the Pro version having an SSD drive, More USB ports and an optical drive as standard.

Prices start at £249 + delivery. More details are at:

Brexit: We are bracing ourselves for the significant loss of sales and significant extra work for any remaining sales to the EU!

pi-topRO – the new RISC OS portable computer

It has been a long time coming but Fourth Dimension (4D) is now pleased to announce that we are able to supply the first RISC OS portable computer since Acorn’s A4 (launched in 1992).

Based on the ‘pi-top’ and incorporating the Raspberry Pi model B[1].
Extensive work has been undertaken to add full RISC OS support.

pi-topRO in Grey
pi-topRO in Grey

Screen: 13.6″ HD Screen 1366×768 (1360×768 on RISC OS)
Battery Life: 10+ hours
82 key keyboard
16GB microSD card with RISC OS 5
Power saving features!

RISC OS software included:
RISC OS 5 installed
!PowerOff – Turns power off at shutdown
!SpkrSetup – To enable the speaker
!BatteryMon – Reports battery usage including estimated time left
!Brightness – Controls screen brightness
Custom MDF
Screensaver – turns screen power off
!HID with custom setup file

Complete system with Raspberry Pi 2 or 3, software as above, speaker, RTC, and nano WiFi router £499 including UK delivery.

More details and purchasing information is available at

Available for immediate despatch.

The keyboard is 86% the size of a RiscPC keyboard. As with most portable/small keyboards some compromises have had to be made, the function keys are accessed using a ‘Fn’ modifier key. Break and most normal keys are available.

Update for pre announcement purchasers: The ‘Fn’ modifier key will work correctly if in !Configure you set ‘Num Lock’ OFF! NB. Not having to use the ‘pi-top’ modifier key also seems to significantly reduce spurious key entry and repeats. Thanks to Jon Abbott for spotting the cause.

The system is also available without a nano WiFi router and/or speaker. Software and hardware upgrades are available separately for users who have already purchased a pi-top.

Software and hardware upgrade kits for the pi-topCEED coming soon!

[1]Users can choose the latest model Raspberry Pi, the Pi 3, or go with the Pi 2 for currently greater software compatibility.

Measuring your Raspberry Pi’s low power!

We all know that the Raspberry Pi is low power, but just how low is the power consumption of your set up?
Measuring the voltage is easy with a digital meter but measuring current (to give you power) is awkward as you need to break into the power line and wire it through the meter whilst maintaining good contact at each join. Our USB Voltage & Current meter is plug and play and will tell you accurately just how much power you are using (Power in Watts = Volts x Amps) by giving you voltage as well as the current you can also detect under specced PSUs or dodgy cables.

Our neat little USB Voltage & Current meter has a USB A plug and socket and measures the power coming out of a USB socket so we include suitable adaptors/cables.

If powering your Model A, B or B+ Pi via its microUSB socket this will do the job:
Photo of DVM connected to a Pi B+
For specs and more details or to buy please see our Order Page

If you are reverse powering a Model A or B through a Pi’s USB A socket then a different cable & adaptor is required, as shown below:
Photo of Digital Meter measuring power going into a USB A Socket
For specs and more details or to buy please see our Order Page

n.b. We could have used a solid USB A plug to plug adaptor but that would result in a 10cm long solid block being plugged into the Pi’s USB socket which could mechanically strain the socket more than we think advisable. By using a good quality USB A- A cable no significant voltage loss is made.

Adding a meter, cable & adaptor will affect the power getting through, but we were very pleasantly surprised to see that measuring the voltage on the Pi TP1 to TP2 only dropped 0.06V when the meter with adaptor and cable was added.

When testing on a reverse power model B, a cheap 55cm USB A -A lead we tested had a 1V drop across it!

Backing up $.!Boot on the same drive could save you money?

The newsgroups and forums often have postings from people whose RISC OS computer isn’t booting properly due to problems within $.!Boot. Reverting to an older copy of !Boot often fixes the problem, but when was the last time you backed up !Boot to elsewhere on your main drive?

Having backups elsewhere is very important but the backup may not be accessible without the computer booting correctly. e.g. if stored on a NAS or another computer and your networking isn’t working! Over the years customers have ended up paying us for telephone support or had to bring/send their computer to us after something went wrong in their $.!Boot and they were unable to fix it themselves. Keeping a same-drive copy of $.!Boot makes it a lot easier to recover from a non working $.!Boot and could save you money and a lot of hassle.

We recommend making a copy at least every six months and also every time you make significant changes such as updating from RISC OS 5.19 to 5.20 or 5.21.

Create a $.Utilities.Copy!Boot directory, then inside that directory create another directory with OS version followed by the date in yyyymmdd order e.g. 521-20131230 to give $.Utilities.Copy!Boot.521-20131230

If you use !NewsDir/MessengerPro, Ghostscript(PrintPDF) or anything else that stores large amounts of data inside !Boot see note [1] below first.

[A] Copy $.!Boot into the created directory e.g. $.Utilities.Copy!Boot.519-20131230.
If you moved anything temporarily out of $.!Boot MOVE that back in now.

Now would be a good time to make a copy of your CMOS, using !SaveCMOS or on later versions of RISC OS press Menu button over the Configuration window!
After making the copy why not clear out the contents of !Scrap then shutdown and restart your computer to check all is well.

After you have done it a few times over the months/years you may want to delete some of the other older copies to free up disc space.

In the future if you end up with the computer not fully booting then:
Rename $.Boot to $.Duff!Boot and then COPY (not move unless disc space is too small) your latest backup of the latest !Boot you have back to the root directory of your boot drive. If you previously had !NewsDir in $.Resources MOVE that back from $.Duff!Boot. Reboot

If you are using a dual partition SD card to boot from e.g. PandaBoard, Raspberry Pi, BeagleBoard etc. then do not do the above, as a special process is required. I will blog about this soon.

Chris Evans


[1] GhostScript/PrintPDF is 32MB and !NewsDir, which is part of MessengerPro, can become very large (100MB+). By default both are stored in $.!Boot.Resources.

If you have lots of spare disc capacity and time you could use the simple method above at [A], otherwise !Ghostscr and !NewsDir can be moved out temporarily or permanently to make it easier to copy $.!Boot.

If moving !NewsDir, ensure no email or news transfers can take place. e.g. Quit Messenger Pro & NetFetch (Hermes/POPStar), or unplugging the network cable is one sure way! If after making the changes, backing up, rebooting and running Messenger Pro you get a message about creating a NewsDir DON’T.
Go back and make sure !NewsDir is seen before Messenger is run.

If the move is temporary I’d suggest moving it to the root directory of your boot drive e.g. so it becomes $.!NewsDir. Now proceed to [A] above.

If you want to avoid having to move it in future then it can go anywhere on a local drive but if you have a $.Internet, $.Comms or $.Utilities as appropriate. Do ensure that they are ‘seen’ (filer booted) before !MessengerPro/!PrintPDF is loaded, so during booting is best. The contents of $.Utilities, $.Apps and $.Utilities are filer booted during booting automatically. Remember where you put them and if you have a technical query with MessengerPro it may worth mentioning.
You can now go back to [A] and make your backup.

Leaking Batteries, Dead Clocks, Storing computers.

What goes wrong, how to fix it and how to long term store unused computers avoiding problems.


The rest of the A4000 above, not near the battery is in very good condition!

From the A5000 onwards Acorn soldered batteries[1] to the motherboard on all of their computers. If the computer is regularly used and in a normal house temperature range the batteries seem to last indefinitely. If however they are left off for months and/or subject to a wider temperature range, the battery can quickly start to chemically break down. Unfortunately it will still retain the CMOS settings whilst slowly corroding the PCB and components around it, meaning if the CMOS settings start to be lost significant other damage will normally have already have occurred. A5000 batteries are going to be up to 22 years old! And RiscPC’s 19 years with the last RiscPCs being sold in 2003.

To avoid the problem of a leaking battery when a computer needs to be put into storage we like others removed the battery which solves any battery leakage problem but when a battery is refitted we like others found that the clock often will not restart. There is a ‘kick CMOS’ utility that has been known to restart stalled clocks but hasn’t ever worked for us when a battery is refitted.

Whether you use your computer daily or want to put an old one to one side: Annually check visually the battery (For its position: see [2]) If it has started going furry replace it straight away (We can supply the battery for you to fit [3] or we can fit it, arranging collection and return if required.

Once you know that the battery is o.k. if you do need to store a computer even if only for a few weeks do ensure it is not subject to extreme temperatures we’ve have seen computers that were only stored for a few months in a loft or house attached garage batteries start to degrade. If it is for a longer period then store it on its side with PSU to the bottom should ensure that any leakage is onto the PSU’s metal case. Annually or every six months if possible plug it in and turn it on, checking that the date and time are correct. 24hours left powered would be good!

A damaged PCB may be repairable but this is a very time consuming operation with the clock chip being surface mounted and may ultimately be unsuccessful so we have in the past recommended replacement motherboards. There may come a time when motherboards become so rare (i.e. more expensive) that repairing may be economic.

If no battery damage has taken place but the clock no longer works we can replace the surface mount clock, this will cost about £45 for labour and parts but excluding collection and return.

There is now another alternative! (Cue the sales plug!)

Replacement clock module for the RiscPC, A7000+, A7000, A5000, A4000, A3020, A3010 and A3000!

Podule version for A5000, A7000, A7000+ & RiscPC (also A3000 if external Podule connector used): £26 + £2 P&P Order Page
MiniPodule Version for: A3000, A3010, A3020 & A4000: £26 + £2 P&P Order Page

n.b. we can even hire you one of the above if you are not sure it will solve your problem.
Podule clock module hire: Podule Hire
MiniPodule clock module hire: MiniPodule Hire

No additional software is required as the operating system will automatically recognise the clock and CMOS RAM
If all the Podule slots are in use on your RiscPC or A5000 we can supply a suitable solution!

Availability: Limited stocks available from stock! More stocks are available within 7-10 days

Whilst fitting the Clock Podule/miniPodule is very simple (no soldering required) you may have to disable the old clock.
More information including downloadable Fitting Instruction PDFs are here:

[1] Being a single cell we shouldn’t really call them batteries but the usage has now entered common usage and is what people search for!

[2] Downloadable Fitting Instruction PDFs have photos of the battery position on all of the computers see here:

[3] A3000/A540 CMOS battery (Horizontal mounting) can be ordered at: Order Page
A30x0, A5000 & RiscPC etc. CMOS battery (Vertical mounting) can be ordered at: Order Page


Add a power switch to your Raspberry Pi!

The Pi has no on board power switch, which can be a pain! Unplugging and re-plugging the power cable isn’t ideal.

However you power your Pi we probably have a power switching option for you, basically whatever cable carries the power we can provide a version with an in-line switch or an extension cable with one!


Only NINE options!

Powering a Pi via its microUSB socket is normally the best option as that leaves both USB ports free for data. The most common option is a dedicated PSU: PSU for Raspberry Pi UK (Mains plug to microUSB plug) 1200mA with in-line On/Off Switch


Standard 2.1mm DC socket to microUSB plug with in-line switch. Very useful if you want to power other items like small LCD monitors also at 5V as you can then use a DC splitter cable and run everything from one PSU! Also could be used with some Power over Ethernet (POE) units including ‘Spare Wires POE’


Standard 2.1mm DC plug to microUSB plug with in-line switch. A 2.1mm plug version of the above for use with equipment that can supply power from a 2.1mm socket like some POE adaptors e.g. TL-POE10R (POE10R + Switched cable)


If you power your Pi via its microUSB socket then this short lead can plug in-line with whatever your current power source is: microUSB extension cable with in-line switch (microUSB Female to microUSB Male 20cm approx.)


USB A Male to microUSB Male for Raspberry Pi with in-line Power Switch
For powering a Pi through its microUSB socket from a powered hub or other computer’s USB port or a PSU with USB A socket/s


USB A extension cable USB Power/Data cable USB A Female to USB A Male for Raspberry Pi with in-line Power Switch.
Short extension cable with ON/OFF switch suitable for powering your Revision 2 Pi via a USB A socket. One use would be for connecting to a powered hub with captive input cable


USB Power/Data cable USB A plug to USB B for Raspberry Pi including Power Switch
Power and data cable with ON/OFF switch for powering your Revision 2 Pi via its USB A socket from a powered HUB with a USB B socket.


Combined USB Power and Data cable for Atrix LapDock to Raspberry Pi including power switch
Provides a very neat solution for connecting an Atrix LapDock to your Pi.
Connects the microUSB on an Atrix LapDock to Raspberry Pi Rev.2 USB port, providing a USB connection and switched power. Upon the advent of the MK2 Pi we realised that a much neater solution than was previously used (modified splitter cables) was a microUSB Female to USB A Male but we couldn’t find such a cable, so set about making one. microUSB Male or Female cannot be hand assembled reliably but we could source factory made microUSB extension leads, so all we needed to do was solder on a standard USB A Plug, but even that we decided would be difficult to do to the quality needed for a commercial product. Then we had a minor Eureka moment and realised that if we put an in-line switch mid cable we could could use factory assembled leads for the two parts and make the in-line connections within the switch for a reliable professional looking cable. When used with our microHDMI Female to HDMI Male cable it makes a simple, neat LapDock Pi system.


iTX/ATX POWER Control Module & Real Time Clock module for the Raspberry Pi
I’m planning a more detailed blog about the iTX/ATX/? Power Control module later.


All of the above are normally available from stock!
We ship world wide and can offer quantity discounts on orders of five or more

Stockist of the world’s largest range of Raspberry Pi accessories