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lappy aboard
by Phil Thane 09 May '17

09 May '17

This is Linux related, sort of, so I hope ALUG don't mind the apparently random question. (cc'd to my old LUG in Wrexham, they're used to mad questions from me). I have just bought a canal/river boat and want to use my Linux laptop on it. The PSU for it is labelled 19v, 4.7 amps. The boat runs on 12v. The simplest but quite pricy option is to get an inverter to create 220v AC then use the standard PSU but apart from cost it lacks elegance. The boat has 2 completely separate circuits (at present, I'll probably re-wire it next winter). There is a 12v battery charged by the engine that is used for the engine starter and a few ancillaries such as the horn and nav lights. The there is another 12v battery charged by a solar panel on the roof used for cabin lights. If I connect the two in series I should get 24v then I should be able to acquire (or even assemble) a DC-DC voltage regulator to bring it down to 19v. Anyone see any problems with that? -- Phil Thane www.pthane.co.uk phil(a)pthane.co.uk 01767 449759 07582 750607 Twitter @pthane

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Re: [ALUG] lappy aboard
by Noel Galer 08 May '17

08 May '17

>-----Original Message----- >From: main [mailto:main-bounces@lists.alug.org.uk] On Behalf Of Phil Thane >Sent: Monday, May 08, 2017 7:41 PM >To: main(a)lists.alug.org.uk >Cc: relay(a)wrexham-lug.org >Subject: [ALUG] lappy aboard > >This is Linux related, sort of, so I hope ALUG don't mind the apparently >random question. (cc'd to my old LUG in Wrexham, they're used to mad >questions >from me). > >I have just bought a canal/river boat and want to use my Linux laptop on >it. >The PSU for it is labelled 19v, 4.7 amps. The boat runs on 12v. The >simplest >but quite pricy option is to get an inverter to create 220v AC then use the >standard PSU but apart from cost it lacks elegance. > >The boat has 2 completely separate circuits (at present, I'll probably re->wire >it next winter). There is a 12v battery charged by the engine that is used >for >the engine starter and a few ancillaries such as the horn and nav lights. >The >there is another 12v battery charged by a solar panel on the roof used for >cabin lights. > >If I connect the two in series I should get 24v then I should be able to >acquire (or even assemble) a DC-DC voltage regulator to bring it down to >19v. > >Anyone see any problems with that? > >-- >Phil Thane > >www.pthane.co.uk >phil(a)pthane.co.uk >01767 449759 >07582 750607 >Twitter @pthane May I make an alternative suggestion ? There are lots of really inexpensive 'Boost' or 'Step-Up' regulators now available on eBay. These are switch mode and therefore very efficient too. It is a common application to use one of these to provide 24V from a 12V system and 19V would not be a problem as they are mostly adjustable. Here is a link to such an item that might be suitable ( I have no financial or other interest in this item or supplier, it was picked at random ):- http://www.ebay.co.uk/itm/New-DC-Converter-150W-10-32V-to-12-35V-Boost-S tep-up-Power-Supply-Module-/252691490519?hash=item3ad59626d7:g:LxQAAOSw2 41YWsVX This is just an example, there are plenty more, larger and smaller, but this might do the job with a bit more heat sinking as is recommended. There are a few caveats too. Some laptop power supplies, Dell being an example, use an extra wire ( with Dell it's a small signal only pin in the centre ) to provide a power pack identification. If not present, things don't work too well despite supplying the correct voltage and sufficient current. This is supposedly to ensure the correct power rated pack is used, but you and I might just think it is to prevent after market PSUs from being used. If your source battery goes flat ( under 10.5V = zero charge ) a boost regulator will just keep sucking charge out of a lead acid battery and damage it, but then so might any other drain on that battery, e.g. lights. If you connect the two 12V systems in series as you suggest, you will be ok as long as both do not share a common ground line. I have no idea if this might be the case. Also, when one system is depleted, lets face it they are unlikely to have the same capacity, i.e. one goes flat as above ( < 10.5V ) damage could still occur to one system. But if you do, a quick look on eBay for a 'Buck' regulator similar to the link I gave, would do that job. If you decide to use a boost regulator and end up with one that has a Constant Current control, don't be tempted to set this to the current on the laptop power supply. I would set it somewhat higher, in your case 6A or more, or to maximum to handle transients when switching on etc. The laptop will only pull the current it needs. I use these things all over the place including my 'Demonic' WolfLite handlamp that instead of a 3W bulb, now has a 40V 1A LED unit running from 18V of LiPo batteries. Best regards, Noel ( Xorsyst ) _______________________________________________ main(a)lists.alug.org.uk http://www.alug.org.uk/ https://lists.alug.org.uk/mailman/listinfo/main Unsubscribe? See message headers or the web site above!

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USB Backup Disk problems
by steve-ALUG＠hst.me.uk 08 May '17

08 May '17

Hi Geniuses! I have a 2TB Seagate USB disk that is being used with backuppc to store daily backups. However, almost every day the backup is failing, and attempting to ls the drive gives "input/output error". Looking through DMESG shows multiple problems reading sectors on the disk, but I've yet to find a particular cause. If I reboot the machine, the drive immediately starts working again. If I fsck it, it reports no errors. The disk has two partitions on it, and the 2nd partition is used by SimpleBackup, and this seems to work fine. I'm currently backing up the backup before I do some more in-depth testing on it, and possibly reformat it. I forgot to mention that both partitions are encrypted. Do people think the disk is broken (bad sectors or hardware problems), or if not, any idea what's going on? On to the next problem. I bought a different 2TB Seagate USB 3 disk which I was intending to use to replace the problematic disk. I managed to set up encrypted partitions on the new disk, and configure the computer so that they would automatically mount on boot.... so I tried to boot the machine and.... the BIOS screen appeared, then it said detecting devices... The old faulty drive is detected, but then the USB 3 Driver is not detected and the machine hangs. It's simple, with the drive connected at boot, the machine won't boot or detect the drive. Without the USB3 drive connected, the machine boots fine. I'm guessing that the machine, which is quite old, can't cope with something about the new drive, perhaps it's slightly too big (although they're both ~2TB), or because it's USB3, and I think the old one is USB2. The old one has a power supply, but the new one doesn't, but I tried connecting it via a powered hub, and no difference. Is there any way round the machine not booting? I don't think there's a updated bios for this old machine. Any ideas, straws to clutch at? Steve

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[ALUG Announce] ALUG Norwich Pub Meet Thursday 11th May
by Viperfang 08 May '17

08 May '17

ALUG Announce Please send announcements to Announce(a)lists.alug.org.uk Unsub, change settings via https://lists.alug.org.uk/mailman/listinfo/announce ----- Hello Norwich Aluggers, Our monthly ALUG Norwich social meeting will be held this Thursday, 11th May at The Coach and Horses (82 Thorpe Road, Norwich, NR1 1BA). The meeting officially starts at 8pm, although some people may arrive earlier. More information on those people can be found on the list and the IRC channel. If you are unsure if you will recognise us then make yourself and your intent to attend known by either posting on list or visiting us on IRC so we can look out for you rather than hiding in the corner. Optionally you could ask at the bar if they know where the geeky computer weirdos are and they'll point you in the right direction (seriously!). Another possibility is look for heaps of electronics on a table that may possibly look like movie props that would used for detonating explosives. Feel free to bring electronics/laptops/gadgets to the meet, you will by no means be alone. Ben Bewick aka Viperfang NB: This mail is automated, please refer to the usual sources for more information. ALUG Contact Details: Website : http://www.alug.org.uk/ IRC : #alug on irc.alug.org.uk List : http://lists.alug.org.uk/mailman/listinfo Twitter : http://twitter.com/anglianlug Identica: TBA Facebook: http://www.facebook.com/group.php?gid=2381613902 ----- Send discussion replies to main(a)lists.alug.org.uk (Reply-To set) Unsub, change settings via https://lists.alug.org.uk/mailman/listinfo/announce

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HMRC payroll software and zlib
by Jenny Hopkins 02 May '17

02 May '17

Hi all, I'm attempting to set up payroll on debian jessie using the HMRC's payroll software for linux. When I try and run it, however, I get the following error: zipimport.ZipImportError: can't decompress data; zlib not available Fatal Python error: unable to locate initialization module I've installed these packages, but no change. libjzlib-java zlib1g:amd64 zlib1g-dev:amd64 zlibc Following a similar thread for this error, I ran python and got the following info: >>> zlib.__version__ '1.0' Any ideas on what else I need to install, or what the problem could be? Thanks, Jenny

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2600 meeting at 18:00 on Friday the 5th May.
by Viperfang 02 May '17

02 May '17

Quick heads up about this months Norwich 2600 meeting, more info at http://www.norwich2600.co.uk

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DNS lookups with systemd-resolve (Ubuntu 17.04)
by Mark Rogers 24 Apr '17

24 Apr '17

I have a local DNS server, and in it are several hosts, specified both with and without a domain name. Eg: $ dig @192.168.1.5 myhost ... ;; ANSWER SECTION myhost. 0 IN A 192.168.1.123 ... $ dig @192.168.1.5 myhost.mydomain ... ;; ANSWER SECTION myhost.mydomain 0 IN A 192.168.1.123 However, if I don't specify the DNS, the first query (myhost) times out, where the second (myhost.mydomain) still works fine. My PC gets its DNS settings via DHCP. /etc/resolv.conf contains only 127.0.0.53 which as I understand it is systemd-resolve. /run/systemd/resolve/resolv.conf contains only 192.168.1.5 (my DNS). So, in the case of a query for "myhost.mydomain", systemd-resolve is correctly passing the query on to my DNS. But in the case of "myhost" it is not (I don't know what it is doing instead). If I try "ping myhost" I get "Name or service not known". Similarly, if I try ssh mark@myhost. Suggestions? -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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Mesh wireless
by Mark Rogers 24 Apr '17

24 Apr '17

I started looking at a few commercial mesh wireless products, which typically retail at around £300-400 for a typical house. I then Googled and discovered a few Linux mesh wireless projects, such as might suit running on a Pi. Anyone here have any experience of such things? (The biggest obstacle with the Pi is likely to be the slow Ethernet port but there are faster single board computers around that might work better. Regardless, the Pi might be a good place to start playing.) -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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Pub meet + GPG
by Bill Hill 13 Apr '17

13 Apr '17

It has been a while - GPG key signing? -- Red to red, black to black, switch it on, but stand well back.

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Shutdown!
by Michael Goddard 12 Apr '17

12 Apr '17

Using Mint 18.1 on my laptop, when using 'shutdown' it does just that, but then reboots a few seconds afterwards, every time recently! Tia, Michael -- Michael Goddard <emmjee(a)mypostoffice.co.uk>

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