Audio Reset
pulseaudio --kill; sleep 2s; sudo alsa force-reload ; pulseaudio --start
Restart audio application, e.g. Spotify
Author Archives: James
Add Suspend icon to the KDE Application Menu
To add the Suspend icon to the KDE Application Menu
- Click the KDE icon (bottom left hand corner) to bring up the Application Menu
- Click “Power/Session” on right-hand list to bring up list of Shutdown Options
- Right-click Suspend and select Add to Favorites
Similarly you can add or remove other shutdown icons.
HP 7520 WiFi scanning not working in Mac OS High Sierra
If when installing the printer with HP Easy Start you get a warning that the scanner does not support “Bonjour” and continue you’ll end up with a working printer but no scanner!
In most cases this happens because you have a dual band router advertising 2.4GHz and 5GHz on the same SSID networks and the printer latches onto the 5GHz network. Simply put the HP 7420 scanner does not work on the 5GHz network.
The solution is to disable the 5GHz network or rename its SSID and ensure your printer does not use it, i.e. is connected to the 2.4GHz SSID. Once done uninstall the HP printer software using HP Uninstaller. Reinstall the printer using HP Easy Start. This time you get no scanner warning and end up with both printer and scanner working.
Real World WiFi Speeds
Real World Wi-Fi Speeds
| IEEE standard | Wi-Fi Alliance Standard | Theoretical Speed | Real-world Speed |
| 802.11ax | Wi-Fi 6 | 10Gps | 700Mbps |
| 802.11ac | Wi-Fi 5 | 1.3Gps | 200Mbps |
| 802.11n | Wi-Fi 4 | 600Mbps | 150Mbps |
Wireless Broadband Alliance (WBA) real world trials carried out in the “hostile” environment of the Mettis Aerospace facility in the UK West Midlands.
https://www.theregister.co.uk/2019/12/05/wifi6_700mbps_speeds/
Linux Content Search Tool
Use Catfish to find files and file content quickly – note content search only works for text type files. Use Recoll for other file types.
Install using Synaptic Package Manager or from Terminal as follows:
sudo apt install catfish
Run it by selecting it from from Utilities or use the Search function and enter Catfish to locate.
Once running you should see screen below.
To search for content first click the settings cog and check “Search File Contents”. This will then force Catfish to search for the string in the files within the top directory you have selected to the left of the search box. In this example we are searching for the content string “tooltip” within files in the the top folder “scss”. The number of hits (3) and files are displayed that contain “tooltip” in the main window. To open a file double-click it.
To search for file names only uncheck “Search File Contents”
Windows 10 F8 Safe Mode Boot
Follow steps below to enable F8 safe mode boot (applies to Windows 10 and 8.1):
- Boot PC using Windows 10 (8.1) iso USB flash drive or DVD
- Click Next to skip the first screen
- Press Shift + F10 To open advanced Command prompt window
Type the following command to enable F8 Safe Mode boot key:
bcdedit /set {default} bootmenupolicy legacy
Type Exit and press Enter to quit the Command Prompt. Remove your usb flash drive or DVD and turn your computer off. When you start your PC, you can now press F8 to get the Advanced Boot Options menu
Create macOS install usb using Linux
If you don’t have a spare Mac or your Mac is too old to download macOS from the Apple App Store then use the method below.
Create account on hackintosh.download
The download required macOS from https://www.hackintosh.download/category/3-macos/
Insert a usb (16GB+ recommended) into Linux PC usb port and run Terminal
Use fdisk to determine your usb dev name letter, e.g. /dev/sdc. It is very important to note the correct device letter or you may overwrite your own system or data drive!
sudo fdisk -l
Use dm2img to copy macOS (OS X El Capitan in this example) to your usb device (sdc in this example). This completely overwrites whatever is on the usb drive already!
sudo apt install dmg2img # install dmg2img if not installed sudo dmg2img -v -i ./EL_Capitan.dmg -o /dev/sdc Output from dmg2img... dmg2img v1.6.7 (c) vu1tur (to@vu1tur.eu.org) ./EL_Capitan.dmg --> /dev/sdc reading property list, 361779 bytes from address 6237611619 ... partition 0: begin=192, size=430, decoded=284 partition 1: begin=908, size=430, decoded=284 partition 2: begin=1611, size=356137, decoded=239844 decompressing: opening partition 0 ... [2] 100.00% ok opening partition 1 ... [2] 100.00% ok opening partition 2 ... [5991] 100.00% ok
When complete eject the usb to flush IO buffers (important!) by clicking on the usb icon on the desktop and click remove | eject.
Insert usb in your Mac and power-up holding down the Alt | Option key until the Install usb icon is displayed in the middle of the screen.
Select the install usb to install macOS
Once in Recovery mode select Disk Utility to erase disk (if new drive or clean install)
Exit Disk Utility
Select mac OS to install from main menu and install to your main HDD or SSD
Note: the download source above is not Apple approved. To be safe, once your Mac is up and running, download the mac OS again from the Apple Store and re-create the install usb and carry out a clean install.
Useful Linux Terminal Commands
Display details about firmware, cache, memory
$ sudo lshw -C memory
*-firmware
description: BIOS
vendor: FUJITSU // Phoenix Technologies Ltd.
physical id: 0
version: 6.00 R1.06.3012.A1
date: 04/21/2011
size: 110KiB
capacity: 4032KiB
capabilities: pci pnp upgrade shadowing escd cdboot bootselect int13floppynec int13floppytoshiba int13floppy360 int13floppy1200 int13floppy720 int13floppy2880 int5printscreen int9keyboard int14serial int17printer int10video acpi usb ls120boot zipboot biosbootspecification
*-cache:0
description: L1 cache
physical id: 5
slot: L1 Cache
size: 64KiB
capacity: 64KiB
capabilities: burst synchronous internal write-through data
configuration: level=1
...
*-memory
description: System Memory
physical id: 2a
slot: System board or motherboard
size: 16GiB
*-bank:0
description: DIMM DDR3 Synchronous 1067 MHz (0.9 ns)
product: 99U5471-021.A00LF
vendor: Toshiba
physical id: 0
serial: DE131F7C
slot: Slot-1
size: 4GiB
width: 64 bits
clock: 1067MHz (0.9ns)
...
Test and Benchmark 3D Graphics
sudo apt install glmark2 glmark2
Command Prompt
Some less well known Windows 7, 8.1, 10 Terminal (cmd) commands
| Command | Description |
| powercfg /batteryreport | Detailed battery diagnostics > html |
| netsh wlan show wlanreport | WLAN data last 3 days > html |
| Alt+Enter | Full screen mode |
| F7 | List previous commands |
| doskey /history > c:\cmd.txt | Save command history to \cmd.txt to view last saved history session |
| msinfo32 | System Summary > BIOS version amongst others |
| findstr /s dinosaur *.txt | Search inside your files with findstr add /s to search subfolders |
| sfc /scannow |
Fixes corrupted system files by replacing them with fresh ones from the local Windows recovery image |
| dism /online/cleanup-image /checkhealth |
Check the health of the recovery image. If you see a message saying corruption has occurred run command below |
| dism /online /cleanup-image /restorehealth |
Fix recovery image. Only run if you have Checkhealth errors |
| powershell |
Switch to Powershell in same window |
| start powershell | Start Powershell in a new window |
| Get-AppXPackage -AllUsers | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register “$($_.InstallLocation)\AppXManifest.xml”} | Powershell command to reinstall Microsoft Store core Windows 10 apps |
| cipher /e c:\Vault |
Replace “c:Vault” with the Folder or file to encrypt. To unencrypt right-click folder or file, select Properties; Advanced and untick “Encrypt contents to secure data” option. |
| shutdown /r /o |
Boot to Windows 10 advanced options |
| netsh wlan show profile netsh wlan show profile WiFi-name key=clear |
Recover forgotten WiFi password. Replace WiFi-name with the one shown in list of network names (1st command). Scroll through results to see password shown against WiFi-name |
| robocopy c:\users\username\Documents d:\backup\Documents /mir /copyall /dcopy:T /r:0 /w:0 /log:c:\users\username\log.txt /tee |
Copy folders fast – mirror the source to the destination copying all files and folders, including empty ones + all file attributes including NTFS permissions and copy timestamps and retry 0 times and wait 0 secs between retries and logfile and log output to console and logfile |
Create bootable usb using DD
This method depends on the iso file being designed as bootable, e.g Kaspersky Rescue Disk or Bitdefender Rescue CD, etc.
Plug in the USB flash drive and list its device name using fdisk
sudo fdisk -l . . . Disk /dev/sdc: 3.8 GiB, 4009754624 bytes, 7831552 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x052e500d Device Boot Start End Sectors Size Id Type /dev/sdc1 * 2048 7831551 7829504 3.8G c W95 FAT32 (LBA)
Unmount the device partition, e.g. sdc1.
umount /dev/sdc1
Copy the iso. file to the device (sdc) not the partition (sdc1). Note the larger block size (4M, default 512bytes) to speed up the transfer. The usb light will flash during copying. Note this can take a long time depending on iso file size. Be patient. When finished dd displays a summary report of bytes copied.
sudo dd if=filename.iso of=/dev/sdc bs=4M
Finally flush the io buffers and eject
sync sudo eject /dev/sdc
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