Archive for the ‘Computer Hardware Interfacing’ Category

Just Your Average Linux WiFi Adventure

Sunday, February 1st, 2015

The goal seemed simple enough.  An existing Linux router with a 2.4GHz TP-Link TL-WN822N v2.0 802.11N USB dongle in AP mode was serving a home network consisting of a mix of devices capable of 2.4GHz and 5GHz operation.  Almost two dozen reachable 2.4GHz networks were nearby, a situation that took the blame for a great deal of wireless dropouts and sluggish performance.  Since by comparison only a few 5GHz networks were penetrating the apartment, adding a USB Edimax EW-7822UAC was the goal, to add 5GHz 802.11AC capability to the router in a bridged configuration with the existing connection.  Well, things always sound simple in concept… (more…)

Setup Chromecast With Transcoding UPnP Media Server Located On A Different Network

Saturday, August 30th, 2014

Here are some notes on my configuration that allows the following:

  • Chromecast on wireless subnet to play video
  • Smartphone(s) on wireless subnet using Avia/BubbleUPnP to select video and control Chromecast
  • Mediatomb Linux server, on a different network segment, transcoding any video format to Chromecast format in realtime
  • Linux router at the center with wired and wireless connections


Why does USB lock up my system with the Intel Providence PR440FX motherboard?

Tuesday, December 10th, 2013

In short it’s because the BIOS routes IRQ lines incorrectly in IO-APIC mode.  Disable IO-APIC mode if you want to use the onboard USB on a PR440FX motherboard.

See the following links.


Matrox G200 (SE) in SR2600 server fails to start X server on CentOS 5

Tuesday, December 10th, 2013

On CentOS 5 (and possibly the corresponding RHEL), the Matrox G200 driver fails when using an embedded G200SE on a SR2600 server.  If you run the X server under gdb or look at the last lines of the Xorg.0.log output, you can see that the X server stopped loading due to the driver module producing a segmentation fault.  The segmentation fault is due to incorrect probing of the available memory size.


Using cgminer’s OpenCL interface with ATI HD 4850 video card

Wednesday, November 6th, 2013

The problem:  Older versions of AMD’s APP (Accelerated Parallel Processing) OpenCL SDK are recommended for use with older Radeon chipsets, but produce segmentation faults in string handling code or other inoperability when used with newer Linux distributions.  Version 2.4 through 2.6 exhibit the problem.  However, version 2.8 does not support, probably among others, the RV770 chipset used in the HD 4850.

The solution:  Use version 2.7 of AMD’s APP when using cgminer with an ATI HD 4850 video card on current Linux distributions.

Reflections on Sans Digital TR5UT External USB/eSATA RAID Enclosure

Thursday, November 8th, 2012

After having used this enclosure for about two years, I feel qualified to comment on my experiences with it, and best practices that I would recommend.


Why were Athlon/VIA systems so notoriously flaky back in the day?

Friday, July 31st, 2009

I remember fondly the NASDAQ bubble days, when it seemed like everyone was upgrading their PC every six months to be able to do useful and fun things, like play the newest 3D games (or to take advantage of the emerging high-speed internet without being slowed down by the piles of cable/DSL ISP crapware that came on the modem install CD).

Back then, custom PC shops competed with the big-box system builders by offering cheaper AMD Athlon based systems that frequently outperformed the much more expensive Intel Pentium III based systems, especially when unlocked and overclocked. But a common thread in the day was debating whether a motherboard with an Athlon CPU and a VIA chipset would be stable enough for the customer’s needs, or if his system should be specified with an Intel CPU and a 440BX based motherboard instead.


Hardware choices for my retro-utility/gaming rig

Tuesday, July 7th, 2009

What hardware goes into a machine that exists for the purpose of interfacing with old hardware and software?


Notes on programming Creative Sound Blaster series ISA cards

Monday, July 6th, 2009

In the world of PC hardware, Sound Blaster cards were the market leader in terms of install base. There are three different types of Sound Blaster cards which interest us. The types are derived from the BLASTER environment variable from DOS. We discuss the non-Vibra and non-PCI types only, because compatibility with software written for the standard “classic” Sound Blaster series was really suffering with PCI and Vibra.

Why doesn’t Slackware run on my old 386?

Monday, July 6th, 2009

It might seem like a laughable question. After all, who uses a 386 anymore? Well, one reason might be for integrating legacy industrial hardware with newer technology. Or utilizing legacy PC hardware for which a modern equivalent does not exist.

In any case, it is common knowledge that the Slackware kernels up to and including version 8.1 were compiled as 386 kernels. But in Slackware 9.0 and later, the kernels are compiled as 486 kernels, with the exception of the lowmem.i kernel.