If when installing an HP 7520 WiFi printer with HP Easy Start you get a warning that the scanner does not support “Bonjour” then you may 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 SSIDs. In short the HP 7420 only works with the 2.4GHz network.
One solution is to disable the 5GHz network or rename it and only connect the Mac and printer to the 2.4GHz SSID network.
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.
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”.
Follow steps below to enable F8 safe mode boot (applies to Windows 10 and 8.1):
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.
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. double check the target device letter to avoid overwriting the wrong drive.
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)
...
Some less well known Windows 7, 8.1, 10 Terminal (Command prompt) 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 > |
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,
A slip-up of adding an extra ” to a string definition highlights an anomaly in Sass which causes it to flag every line of scss code (including comments) with double quotes as an error including the real error lost in the jungle of errors. See example below with ” added to the end of $fontfamily (not easy to spot) and an excerpt of the Sass compiler error message pointing to valid line of code amongst many more misleading messages.
$fontfamily: "Comic Sans MS",Arial,Helvetica,sans-serif!important"←;
Gibson Research Corp.’s Shields Up port-scanning service at https://www.grc.com/shieldsup will test your router for hundreds of common vulnerabilities, most of which can be mitigated by the router’s administrator.