Computing General

Random things I discovered today…

Odd sort of day really… anyway, some things I discovered / got annoyed by / had a giggle at:

Random observation: When Windows 10 slowly boots, if you have enabled the ‘locate your cursor by pressing Ctrl’ function (I *so* prefer the Mac way that expands the cursor when you shake the mouse!) and use it before the cursor has even appeared it draws it’s circle around the position the cursor will appear at once it has finished messing about and booted sufficiently to work. You know, in 10 minutes time. So, Windows tells the future.

Random thought: how many person-hours per day are wasted in total globally waiting for Windows to boot?

Radom annoyance: my imap-ssl daemon stopped for no reason and will not now restart. It whinges about not being able to find a valid cypher. I had updated the LetsEncrypt certificate but I can’t remember if the imap failed immediately after rebooting or not. Anyway, fiddling with various obvious config settings just made it crash so it’s been deleted…

..which leads me to…

Random successful modification: given the demise of the imap daemon I revisited why I even have a mailbox on my Linux server. All I need is a mail hole and postfix does that. A quick edit and rebuild of Postfix’s virtual table and I can redirect any wanted email off to Google, solving the issue and reducing my mail accounts by a third. Neat. After a week or so of checking what email gets dropped on the box I suspect all will be spam and can divert to /dev/null…or spamcop if I can be bothered. One less thing to remember to do when the SSL, sorry TLS certificate gets renewed.



Well, after yesterday’s struggle with network monitoring software, using a plethora of information I could see a way to write code for what I actually needed by the use of snmpwalk and coding OIDs. But I installed MRTG instead!

I’ve used MRTG before and, while the graphics are not as nice as the one that I had but which fell apart when I added a more secure network switch MRTG is one of those nice examples of software that just works. Feed it the IP addresses and (take note o’ failed and thence deleted software) it works everything out and generates a configuration file and a set of HTML pages. No on-the-fly stuff that falls over and has bits falling off. The only negative is I have yet to find a way for it to extract the names assigned to the interfaces in each switch, but it’s no biggie really to simply edit the config file and add the names there which is what I did. I mean, I only have 46 Ethernet ports spread across three switches…!

I may still write some code though, as really all I want is to be able to see what device swamps our broadband and when. But the graphs are kind of nice to have.


15″ MacBook stiff screen

My 15″ MacBook dating to early 2013 (or so it claims) had been getting very difficult to open recently. This culminated in the screen popping up about a quarter of an inch when closed, the magnet just not strong enough to hold on. So, time to get the diddy screwdrivers out. I had looked on the Web for tips and found some discussion of removing the screen to clean the hinges, not something I was looking forward to but I decided to have a look anyway.

On removing the base I was presented with this!

That’s a lot of fluff! Ok, I’ve had it from new, so it’s 8 years of fluff (has it really been 8 years?).

Anyway, after de-fluffing all I did was very carefully, and with a teeny bit of WD40 sprayed onto a cotton bud cleaned the parts of the hinge that I could see. And that did the trick. No need to dismantle or otherwise adjust anything fortunately. YMMV of course, but it worked out for me.

But… 8 years! And it will not take the latest OS… sad.


MacBook Pro battery replacement

Recently the battery in one of our old MacBook Pro laptops gave up the ghost, big time. First, it would run for a few minutes but not long after it was totally dead, with the Mac loosing power completely if the charger was removed. We replaced this Mac as it was a vital component in our IT armoury but I wanted to fix it and, hopefully sell it as working. It’s a 2015 13″ model.

So, off to the excellent iFixit site, specifically in our case this. The guys that put these pages together are a huge help to those of us daring to venture into repairing our own kit. Anyway, I have a decent range of tools for abusing small electronic devices such as phones and laptops, so why not?

The case comes apart quite easily:

Getting the battery unstuck – my goodness they glue them in well – is hard but not so much so that it cannot be done with care. A note here, this is solely from my own experience, do not rely on this!

It took maybe 20 minutes and 4 old credit cards to very carefully unstick the entire battery. I had a new OEM battery from the Replace Base that arrived within a day, came in a neat package and included the necessary screwdrivers but I already have plenty. The price of the battery was somewhere between the cheapest eBay price for a non-OEM part and the price from Apple. Everything went back together with no screws left over (!) and the Mac works nicely, holding 100% charge and with a battery recharge indicator of 1. oh yes and I managed to throw Big Sur onto the Mac too.

I have to say though, I went through this because I have some time, being retired, and I wanted to not be beaten by something that should be simple, i.e. changing a battery. Having been through the exercise, and bearing creases on my palms for a couple of days from the force needed to unstick the battery, paying Apple to do this is actually fairly good value for money!


Why is this so hard

I had to edit and then print an official form downloaded from a Government website today. All it needed was some names and addresses putting in at the prescribed lines. Easy… hmmm.

First off, the form is an MS Word document. Ok, I have Pages on the Mac. Ah, but the format is wrong and lines appear in places they should not. Oddly, the first half is fine, but the second where it needs a date entering ends up with a line through the date.

Ok. Borrow a laptop that has Word. Download the form again and it was filled in properly. I had to struggle to get a USB stick to be recognised even though it has been in there before – two goes and it found it. This is because I did not want to store the edited document on the laptop at all, well, other than whatever temporary files Windows wants to create.

So, to print.

The laptop will not find the printer

The copy of Word will not print to PDF


Finally I managed to export to PDF, stuff it on the USB, put the USB in the Mac, open it (and check the format is still ok! The ‘p’ in PDF is not always what it makes out to be) and print it.

Two laptops, one USB stick, about 10 edited lines in a document.



Random PC woes

This morning the rig would not go into transmit via wsjt-x. It worked fine last night up to when everything was shut down and there were no changes to anything, hardware or software. Rebooting the PC made no difference. CAT control was working both ways and it was receiving FT8 fine. I noticed that transmitting would sometimes change the rig settings e.g. from data to non-data.

I tried the flrig / fldigi combination but transmitting via this messed the FT450D’s settings up in that it was rapidly triggering tx and the rig decided to engage its internal tuner.

Plugging the two USB connectors into the front USB sockets on the PC made it work but the transmit levels are mad – ALC is triggering and the rig does not generate any decent power with this turned down. ALC is on a knife-edge where it goes from very little power / no ALC via the SignaLink TX control to 50% ALC and proper power output with nothing in between. Fiddling with the audio settings on the PC and in wsjt-x makes little difference.

But changing the Mode to Data/Pkt in Settings -> Radio does improve the ALC business. This was set to None and I cannot remember if this is a change or not.

The audio settings via pavucontrol are set to 100% for the USB audio. This was 120% before as otherwise the rig would keep falling out of Tx on 40m. Wsjt-x’s tune function is holding up on 40m at 100% so there is a change there for no apparent reason.

All the PC USB ports are USB2.0 so there is no difference there. Trying a few CQs on 17m shows that FT8 is being received across Europe so it is all working. The same is true to 40m.

Weird. The only physical differences between it not working at all this morning and now are the two USB cables are plugged into the front sockets and the USB leads are away from the antenna coax. But the latter, i.e. the cable routing has always been along the same path as the coax and it has worked every day without issue.


Corrupt SD cards

Those of you with Raspberry Pi systems or similar (other small sized computers are available!) will feel my pain…

A few days ago my little web and all-sort-of-other-stuff server fell over. I had no idea why but it seemed to reboot ok. I suspected we’d had a very short power outage but checking the other Pi systems (there are 4 here) all had long uptimes. Anyway, it all came back ok, or so it seemed.

It runs a process every minute to grab data off the weather station and displays this on my private website, which it also serves. The website simply tails a log file and was now showing a Linux error message which looked ominous. Checking the Pi it has gained a nice little file system error and the temp file the weather station grabber creates was corrupt. Rebooting cured this (it runs fsck on boot). That cured the weather station data but the problem persists.

So far there are no other obvious issues except it writes ext4-fs warnings to syslog every time something does anything. No biggie, these are only log files.

So, thought I, I’ll fsck the SD card. Ok, can’t do that running so it needs to be mounted on another system. Where do I have an SD reader? My little Samsung Netbook has a version of Ubuntu on it so I can use that.

This is where things went south. The Netbook takes a while to boot but takes an age for the GUI to settle. And I mean 30+ minutes and still it sits there! Come on, I can do a Windows update faster… Ah, found a USB SD card reader, I can use my desktop instead (the Netbook is destined for eBay I suspect). So, let’s plan this logically. I shut the Pi down (a caveat here is it’s also the NFS server and serves a disk to another Pi that does all the CCTV recording… probably better that one had its own disk!!), pull the SD card, stuff it on the desktop Linux box and fsck the filesystem. There’s a danger it will fsck to death and become useless but everything is backed up or can be reinstalled, all I need is a clean SD card. Um…

Ok… scratch that and order some SD cards first! Ugh.