The Testing Blog

Back in 1945, engineers running the Harvard Mark II (an early electromechanical computer at Harvard University) found an actual bug in their hardware – literally, a moth that got stuck in a relay was causing problems. Decades later, we’re still finding “bugs” in our computer hardware and software. Wired has an interesting article on their website talking about History’s Worst Software Bugs, including Intel’s Pentium floating point bug which cost them $475 million to repair. Although the article is a few years old, it’s an interesting read.

And the bugs are still continuing today. Just a few months ago, in 2008, Seagate released their 1.5TB Barracuda hard drives with an error that could hang the hard drive during streaming video or low-speed transfers. When they attempted to release a bug fix, they ended up bricking the 500GB Barracudas for other users!

Just remember these “history lessons” before you release your product to market.

If you’re looking to get any platform, product, etc. ZigBee certified, you probably know that you need to check for 802.15.4 compliance before you move on to the higher layers. However did you know that ZigBee does not mandate the implementation of the full 802.15.4 MAC layer? Some functions of the 802.15.4 MAC are actually even prohibited in ZigBee and their use will cause your platform to be non-compliant. This not only reduces the testing you have to do, but also reduces code size and complexity that is not needed for your stack. Features such as GTS, MAC security, beacon networking, and PAN ID conflict on the MAC layer are just thrown out. In other words, ZigBee will only ask that you test a relatively small portion of the 802.15.4 MAC which should come as good news to all of you out there worrying about fitting all of this code in small memory chips to cut cost!

If you’ve developed several similar USB products, you might be able to get them all USB certified with only one test. Simple changes like product packaging, model numbers, connector vendors/model number, etc. can often be certified with only a few forms filled out. More extensive differences, such as changes to the microcontroller, PCB or RF hardware, may require a retest, but the ultimate decision comes from the USB Compliance Review Board (CRB). More information on what is and is not valid for Qualification by Similarity (QbS) for USB can be found at the USB-IF website.

Just a quick tip for anyone looking to have their Windows hardware WHQL’d (e.g., given a “Certified for Windows Vista” logo, etc.) – Microsoft has made 64-bit drivers MANDATORY. If you’ve designed a hardware product and you want to get it certified, you must also submit an x64 driver. The following text is from the Windows Logo Program Device Requirements Document (pages 86 and 365 as of today – search for “x64″):

All products and drivers (kernel mode or user mode) submitted for Microsoft signature or Logo must support the x64 version of that specific Windows operating system, with certain exceptions described below. This requirement is applicable for Windows Vista and later operating systems. It applies to all logo‘ed and unclassified drivers. x86 driver submissions are optional in all cases. When submitting an x86 driver or device, vendors must also make an x64 bit driver submission.

Just a warning before you get far along the process to get your product tested for WHQL/DTM.

However, Microsoft has been giving a 60 day grace period in which you can submit your x64 bit drivers.

If you’re putting up a new website, it’s common practice to test your website with older versions of popular web browsers and your “required software” (e.g., Flash, Java, etc.) to make sure it is backward compatible. Even if your website is fully compliant to the latest W3C and CSS standards, it still may look very different in different browser/operating system configurations. For example, if you’ve just put up a new website, you may want to try it out using an old version of Internet Explorer or Firefox, maybe Flash 7 or 8, or an old version of Java. Only one problem – where do you find old versions of the software to install?

If you’re looking for older versions of web browser, try the Evolt Browser Archive. Started in 1999, the Evolt Archive has a large variety of older browsers (including little known ones like Cyberdog and iCab) and older versions of many popular browsers (including Internet Explorer all the way back to 1.0).

You can also find older Windows versions of web browsers and other software (including the Microsoft Java VM and Adobe Flash) at OldVersions.com. If you’re trying to find out what most people are using today, you can visit the Browser Statistics from W3C for the latest browsers, operating systems, display depths, etc.

And rather than trashing your current desktop installation of MSIE or Firefox, grab a copy of VirtualBox and create your own virtual machines to test different web browsers.

Welcome everyone to the new blog about quality assurance testing & certification. So, are you looking for help getting your product tested before you go to market? Are you looking to find out how to get through certification testing for USB, MoCA, ZigBee, and a ton of other technologies without hassles? Are you looking for the latest news on technology without having to sort through hundreds of posts & Google Alerts?

You’ve come to the right place. Stop by here and we’ll help you out. And if you’ve any questions about testing or certification, just leave a comment or drop me an email and we’ll see if we can’t help you out!