Adding CUPS server to MacOS 10.7 or later without client.conf

January 5th, 2024 No comments

Since MacOS version 10.7 Lion, it has not been possible to use the ServerName option in the CUPS client.conf configuration to add a remote CUPS and skip the local CUPS server. Instead, printers are expected to be added via the Settings app. However, for some reason, adding the printer there did not work for me. The printer was added successfully and looked fine, but when selecting the printer to print a document, it would display as “Offline” and it would say “Looking for printer” in the Jobs dialog. The fix is easy!

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RT2870/RT3070 ath9k_htc and maximum number of STAs

April 3rd, 2022 No comments

For many years I have been using RT2870/RT3070 USB WiFi dongles and I was happy with them. They have great Linux support thanks to the ath9k_htc driver.

But as number of IoT devices increased, one day one of them couldn’t connect and hostapd was reporting errors like these:

Could not set STA to kernel driver
nl80211: NL80211_CMD_SET_STATION result: -105 (No buffer space available)
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Linux Capabilities in a nutshell

April 24th, 2019 2 comments

Capabilities are being used by many Linux-based software nowadays to limit what a process can do. But I think the documentation is a bit hard to grasp and I found some parts of capabilities implementation confusing so I decided to condense my current knowledge into a shorter article.

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Running x86_64/amd64 executables on PPC64le IBM Power 9 Gentoo

September 23rd, 2018 2 comments

Running android-studio on a Talos II ppc64 machine requires the aapt2 binary. That is currently only a part of the x86_64 build-tools, so I had to learn a way to run x86_64 executables on ppc64 cpu. The first option is full emulation (emulating x86_64 kernel and apps), the other is QEMU’s user mode translation (emulating only user-mode, translating syscalls to a running ppc64 kernel). Let’s have a quick look at the QEMU user-mode translation.

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Missing Android manual

March 11th, 2018 1 comment

We all got Android devices without a proper manual so here are some basics I have learned over time…

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How to boot Windows partition virtually under KVM with UEFI firmware

March 5th, 2018 17 comments

It is actually quite easy to boot Windows virtualized using KVM. But to properly use the UEFI bootloader, suitable QEMU arguments are required. Here is a lightly commented QEMU command I use to boot virtual Windows 10 I have on a separate partition.

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RC5 device addressees and commands are partly “standardized”

March 5th, 2018 6 comments

During my attempt to program an Atmel micro-controller to act as a remote controller sending RC5 commands, the original remote suddenly stopped sending the correct Standby code to the device and I noticed device ID part of the RC5 frame has changed from 0x10 into 0x11. I accidentally switched the original remote to a mode for a different type of appliance! I realized that after I found a nice PDF from Freescale semiconductor showing a table with common device IDs and command IDs.

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Categories: AVR, Electronics, Programming, Uncategorized Tags:

Telegram emoji list with codes and descriptions

February 1st, 2018 19 comments

After almost 2 years of using Telegram, I finally discovered that it is possible to enter emoji using its name after “:” character. Unfortunately I couldn’t find any complete list of available emojis anywhere, so I had to dig deep into the Telegram desktop source code to generate it.

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Samsung printer problem on GNU/Linux (printing black pages)

August 22nd, 2017 3 comments

I’ve been using Samsung ML-2160 printer on Gentoo Linux for some time without problems but then I connected it to a box running Arch Linux and I some problems came up. It was printing almost completely black pages (with a few narrow white strips).

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[cz] Proč je Facebook a Messenger špatný

August 11th, 2017 2 comments

Facebook prý spojuje lidi a umožňuje být neustále s přáteli, aniž bych vystrčil nohu z baráku či postele. Facebook se tváří jako nejlepší kamarád a pomocník, že dělá pro nás to nejlepší. Ale je tomu opravdu tak? Read more…

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