Every lab needs at least one good variable bench power supply. There are so many important features that few manufacturers get all of them right. I have quite a few bench supplies, but the best moderately priced supply I own is the GPP-3323 from GW Instek.

The key features for me are:

• Dual variable outputs 0-32V, 3A max each
• Third limited output meant for digital logic: 1.8/2.5/3.3/5.0V at up to 5A
• Very low-noise output (<= 350uV)
• Outputs can be paralleled for higher current or put in series for higher voltage
• Over-voltage/current/power/temperature protection
• No overshoot on power on/off or load transients
• Intuitive display/user interface
• Keypad for numeric entry of all values
• Individual output enables and also all-output control
• Minimal fan noise
• Programmable via USB and LAN interfaces
• Can generate configurable output waveforms

However, what really distinguishes this power supply from others is that one of the power supplies can be used as an electronic load (up to 50W). This makes this supply unusually useful for developing DC-DC converters and generally characterizing power supplies.

I bought it from TEquipment which I highly recommend as a vendor.

• Product Page
• Specifications
• User Manual
• Supports TestController software (see forum and here)
• Firmware mod
• A review

My oldest laptop is a Lenovo Thinkpad Carbon X1 (6th-gen Type 20KH). I still use this because it is solid, light, significantly smaller than my standard laptop (LG Gram 16), and I have a couple of handy docks for it. I use the Gram if I’m going to be doing significant writing/development because I need the larger screen, but the 14″ X1 is perfect for non-work travel when I only need light/occasional internet access. So I plan to keep it in service for a while.

Because Windows 10 will be end-of-life next year (October 2025), I wanted to upgrade the X1 to Windows 11. The good news is that it supports Win11 (and is now running it). The bad news is that the instructions for upgrade on the Lenovo website are atrocious. If you follow them, in many cases, your laptop will be rendered temporarily un-bootable.

The underlying problem is that the hard drive on many X1s is formatted using the old MBR (master boot record) partition style which is what’s used by the legacy BIOS mode. Windows 11 security requires secure boot UEFI instead of legacy BIOS. UEFI in turn requires booting from a hard drive formatted with GPT rather than MBR. As long as your X1 is set to boot in legacy BIOS mode from a drive with MBR partition table, Windows Update will indicate that your X1 is not able to run Win11. Microsoft’s PC Health Check program (download here) will tell you why.

The good news is that Microsoft provides tools for converting your MBR formatted drive to GPT in place. The bad news is that the process is tricky and the instructions are scattered across the internet…hopefully this post helps. (Note: even though the conversion preserves all data, back everything up before you start this process just in case). You will want to do the following:

1. If you haven’t already created one (and most folks won’t have), you need to create a local password for your user account on your X1. This password is different from the Microsoft online account you are probably using with Windows 10. The local password will be required in the next step. Unfortunately, I didn’t note exactly how I did this, but some instructions that may be useful are here.
2. Check your hard drive to see whether it uses the MBR partition table and, if so, whether it can be converted to GPT (and then convert it). The instructions for this are here. Note that this will require you to boot to a command prompt in a special mode which will require the local password you created in step 1.
3. If the conversion goes well, you can now reboot your X1, enter the BIOS setup and enable Secure Boot under the Security tab. This will likely enable some other things in your settings like the Trusted Platform Module (TPM) which are required by Windows 11 secure boot.
4. If that has gone well, you should be able to boot into Windows 10 again and PC Health Check should indicate that your X1 is suitable for Windows 11. Unfortunately, the Windows Update screen in Settings will still say your X1 doesn’t support Windows 11 so you can’t use the automatic updates to upgrade to Win11.
5. So the last step is to download the Windows 11 Installation Assistant here. When you run the assistant, it should take care of updating your X1 from Win10 to Win11.

My X1 is now running Windows 11 so I can confirm that this works.

A lot of useful information was found on the Lenovo Community Forum here.

We took our first vacation since the pandemic this month (January 2024) and traveled to Sri Lanka. It was a wonderful trip. After roughly 24 hours of total travel, with a stop in Istanbul, we started in Colombo (the capital).

The impetus for our trip was the wedding. of Sanjiv and Sumudu (Deana’s cousin Janthy and her husband Dehan’s son and new daughter-in-law). The wedding was held on the beach behind The Galle Face Hotel. and the setting was incredibly picturesque. It was my first Buddhist wedding and it was filled with symbolism, and ceremony including Kandyan traditional dancers.

We stayed at the Galle Face which is a venerable and impressive 5-star colonial-era hotel. It has been kept up-to-date; the rooms, hotels, restaurants are modern and classy, but it still conveys the history and gravitas of a hotel that’s been in service since the mid-1800s.

Sri Lanka sits on the equator and can be pretty hot. Although we visited in January, the temperature in Colombo stays in the mid-80s and humid year round. One of the many bizarre legacies of British colonialism is that men in Sri Lanka generally wear western suits. Nothing is more miserable in hot weather than a wool suit, high collar, and tie. Linen is a bit better, but still awful. What makes this even more mysterious is that South Asia has extraordinarily beautiful fashion that is meant for the climate. Deana and I visited an Indian store in Ellicott City (India in Style); they have a huge selection, the owner is wonderful and patient, and for better (Deana’s case) or worse (mine), we bought South Asian formal outfits for the wedding. A Kurta is definitely cooler and more comfortable than a suit although in retrospect I would have preferred linen over silk.

Colombo is a large metropolis with heavy traffic, skyscrapers, and diverse neighborhoods. Like many major metropolises, it is also very fashionable and Deana and I quickly realized our American-tourist clothing needed an upgrade. After several visits to House of Fashion (a popular department store that focuses on clothing) we acquired enough warm-weather, but semi-fashionable clothing (and another suitcase to hold it).

We also realized how essential our driver (Amal) was. Driving in Colombo makes driving in New York City look trivial. Aside from the fact that Sri Lankans drive on the left (UK-style), driving anywhere in Sri Lanka is not for the faint of heart whether in dense urban settings or narrow mountain switchbacks. Even in rural areas, overtaking (passing) is an art-form and there are novel road hazards (like elephants) one may not be accustomed to. If you go to Sri Lanka, get a private driver; it is the single best thing you can do. If you can get Amal, you should do so; he is a gem. You can reach him on WhatsApp (the calling app everyone in Sri Lanka uses) or on his website. I’ll talk more about this later in this post.

While in Colombo, we spent time with Deana’s family members including her cousins Lakshman (who lives in Australia), Lakshme (who lives near us), and Dev (who lives in the UK), her mother’s brother: Uncle Rasa and his wife Jaya, her relatives Somes (Colombo), Subo (UK), and Subo’s brother Ram and his wife Kala (Toronto). Lakshman entertained at his condo where I made my one and only mistake of having a drink with ice – Mr. Montezuma made me pay for that drink for about a week. Really really really don’t drink tap water or use ice in Sri Lanka. Anything you drink must come from a sealed bottle or be boiled. Dev took us to the charming Barefoot Cafe (where by coincidence we again saw Lakshme and Lakshman)

From Colombo, we traveled to Nuwara Eliya which is in the mountainous central region of Sri Lanka. There we stayed at another venerable colonial era 5-star hotel: The Grand (which, true to its name, is spectacular). The rooms are amazing, the grounds are beautiful, and the scenery is stunning. Nuwara Eliya is in tea country: the mountainous central part of Sri Lanka. Unlike Colombo (and much of the island where the climate is tropical), the mountains are delightfully cool and dry – a near perfect environment. The area around The Grand is known as “Little England” and is full of European-style architecture and the culture of the area is unique. We had high tea daily, visited a tea plantation and factory,

By coincidence, Subo was staying at The Grand at the same time and Deana was able to spend some time with her there. Did I mention how spectacular the gardens are?

From Nuwara Eliya, we traveled to Kandy, Sri Lanka’s second city and religious center. At Kandy we visited the Temple of the Tooth (the holiest Buddhist temple) and went to a cultural show with traditional dances including an impressive display of fire dancing and eating. Kandy is spectacularly scenic. We stayed at the Amaya Hills (another 5-star hotel) which sported stunning rooms and incredible views. Coincidentally, Deana’s relative Subo and her husband Ram and his wife Kala whom we had been with at the wedding were also staying at The Grand at the same time so we got to meet with them there again.

While staying in Kandy, we visited two ancient Buddhist temples; one was a UNESCO World Heritage sites: the 1st century BCE Dambulla Cave Temple. Both temples involve some climbing; Dambulla is built atop a 500′ rock so there are a lot of steps involved….but they’re worth it and somehow not nearly as difficult as the climb at Sigiriya (later). There are 5 caves at the top, each filled with massive ancient statues and every inch is intricately painted. Of the historic and religious sites we visited, I found Dambulla by far the most impressive. Note: there are a *lot* of monkeys at Dambulla.

From Kandy, we traveled to Sigiriya. On the way we visited the Sri Muthumariamman Hindu Temple in Matale. This is a very old temple which is incredibly intricate

Once we reached the Sigiriya area, we stayed first at The Heritance Kandalama, an unbelievable eco-hotel located in the midst of a nature preserve. It’s really hard to overstate how amazing the Kandalama hotel is. We started in Colombo at a very impressive 5-star hotel and somehow each hotel kept getting better; the Kandalama was hands-down the best. The hotel was designed by a famous Sri Lankan architect (Geoffrey Bawa) and is simply perfect. It is integrated with its natural surroundings in ways reminiscent of Frank Lloyd Wright. From the moment you arrive at the hotel, it is apparent that it has been built to blend in with its surroundings. The hotel is on a lake deep in a nature preserve; wildlife is everywhere and you truly feel like you’re in the jungle. The first night, monkeys stole Deana’s coffee cup and when it rained, several families of monkeys camped out on our balcony. The night was filled with the sounds of birds, monkeys, elephants, etc.

While at Kandalama, we had a chance meeting with the former chairman of the board of the corporation that built the hotel (and a whole chain of similar hotels): Prema Cooray. We had tea with him and he spent quite a long time with us; he is retired, but sharp as a tack, charming, and regaled us with the stories of how the hotel was built, the obstacles it faced (financial, political,etc.and how they were overcome). While we were at Kandalama, we experienced our only rainy day (and it was a great place to experience it); we enjoyed the hotel and spent a good deal of time talking with a delightful young artist from Bahrain (Abdulla Buhijji).

Our plans changed a bit due to the rain, so from Kandalama, we traveled to a nearby hotel: the Cinnamon Lodge in Habarana. Cinnamon Lodge is another highly rated hotel, and if we hadn’t just come from such incredible hotels, would have been impressive. As it was, the lodge felt a bit dated and even though it was actually very pretty. We took a dip in the pool and chatted with two nice British pensioners and the food was quite good. The rooms were reasonably spacious, but were set up as bungalows some distance from the main hotel; like many more traditional Sri Lankan settings, the rooms were air conditioned, but the bathroom was open to the air and overall, it just couldn’t compete with Kandalama.

From Habarana, we visited Sigiriya, another UNESCO World Heritage Site. This too was spectacular: the site of an ancient palace built atop a massive rock surrounded by water gardens. The gardens around Sigiriya are still being excavated, but they are both beautiful and amazing feats of ancient engineering. The earliest activity at Sigiriya was 3rd century BCE and the palace was built in the 4th century CE. As was recommended, I paid (a very small amount) for a guide who was knowledgeable and explained the detailed history of the site as we traveled through it. He was extraordinarily patient with me as I trudged up the 1200 steps (foolishly having gone around noon when it was pretty warm), having to stop several times. The guide does the climb several times a week and was a cardio-god, not even breaking a sweat. The climb is 590′ (59 stories) pretty much straight up…so it will give you a workout. It’s also not great for anyone with even a slight fear of heights. There are several important sites on the climb that did not permit photography including the famous maiden frescoes and mirror wall.

After Sigiriya, Amal arranged a safari through a nearby nature preserve the objective was to see elephants and it very much delivered.
It’s hard to convey just how beautiful the scenery is in Sri Lanka.

…and I will never again complain about deer in the road; this is what a road hazard looks like in Sri Lanka and it is not uncommon. I think the safari was one of the high points for Deana; we saw a ton of wildlife. Like so many things, the safari was arranged on very short notice by Amal. Having a private driver is like traveling with your own travel agency. Everywhere we went, Amal knew the hotels, sites, people, and could arrange whatever we wanted at a moment’s notice, usually for much less than we would have paid if we booked them ourselves.

From Habanara, we moved on to Anuradhapura, one of the 3 ancient capitals of Sri Lanka (along with Kandy and Polonaruwa). Unfortunately, we didn’t get to Polonaruwa due to rain and concerns that some roads might have been flooded.

In Anuradhapura, we stayed at very different lodging: the Arachchi Heritage. This is a private home with two separate, private guest suites and a staff that makes it effectively a boutique hotel. The house is spectacular, like something out of Architectural Digest. It is on a lake and its design, in many ways, reminded us of Kandalama: tightly integrated with nature. The positioning and design of the house capture a constant breeze so even though many parts of the house are open to the outdoors, they remain cool even on a hot day. The house won a Geoffrey Bawa design award. The owners: Chandrika and Siri were charming and wonderful hosts. The food was outstanding, every bit as good as the 5-star hotels and made to order!

While staying at Arachchi, Deana took a cooking lesson given by Chandrika and the in-house cook. The food was really delicious and I couldn’t believe how many dishes were prepared each meal for just two guests. The food at all of the hotels was just amazing; I had hoppers for breakfast every day, often along with pittu and idli. For lunch and diner I had Sri Lankan roti and all sorts of curries: dal, banana blossom, beet, snake gourd, and more.

We visited the extensive Anuradhapura archeological sites and museum. This was the site of an ancient capital and center of education and monastic knowledge. 5000 monks lived on 500 acres with extensive housing, baths, dining, sanitary systems, and remarkable feats of ancient engineering. Our guide (also arranged by Amal) was a young man named Jagat who was knowledgeable, extremely fluent in English, and very enthusiastic about Sri Lanka and its history. We had lunch with Jagat and Amal at the Aliya Resort Hotel in Sigiriya; their website doesn’t do them justice; it was incredibly beautiful and if we visit again we will try to stay there. In general, although Anuradhapura is worth seeing for its historical significance, I didn’t find it as impressive as sites like Sigiriya or Dambulla.

We returned to Colombo from Anuradhapura a day early because Deana had been making plans with relatives and family friends throughout the trip and we needed more time. We stayed at the Kingsbury hotel for the rest of our time in Sri Lanka. It was another 5-star modern hotel with impressive restaurants and facilities. My only complaint about the Colombo hotels is that they frequently host weddings and other events and the parties go on *late*; it wasn’t uncommon for the music outside to go on until 11:30pm or midnight. Sri Lankans like to party.

We visited with Aunt Amithi (Deanas mother’s closest friend); her husband had been an architect and her house was quite beautiful. I wish I’d taken more photos. Amithi herself was lovely and sharp as a tack.

We met Deana’s grade-school (St. Bridget’s Convent) friend Jaish for tea at the Tintagel, another impressive Colombo hotel. Jaish is now a fashion designer and was delightful.

We spent time with Deana’s cousins Janthy and Vilo and Janthy’s husband Dehan who took us to Nuga Gama; a restaurant in the middle of a swanky cosmopolitan hotel that had been created to give them feel of a rural village. At various times there were dancers and other entertainers such as this traditional comedic “devil-dancer”.

We visited Deana’s cousin Punya, her husband Dil, and their daughter Pulisticka (Puli) Jayathilake and her daughter RIddhi near her old house on Kinsey Road. It was neat that Riddhi represented the 5th generation from her family at St. Bridget’s Convent school in Colombo 7.

Deana’s father’s best friend’s son Dev Devendra and his wife took us to lunch at the beautiful Royal Colombo golf club. They are an awesome couple; their daughter lives in relatively nearby Reston, VA and Deana has already been in touch with her.

We had dinner with Deana’s cousin Prabha and her husband at the very nice Chinese restaurant in the Kingsbury hotel.

There’s a lot more to write, but I’m out of gas on this marathon post. It was an amazing trip and one I hope we’ll do again soon. The people were wonderful, the country is beautiful, and we had the benefit of traveling at a time when the exchange rate worked very much in our favor (1USD = 320 LKR). Tourism is a key business for Sri Lanka and it suffered badly during the pandemic. They really want tourism to return which makes for great synergy: tourism dollars and amazing value for tourists; so it is a *great* time to visit Sri Lanka; I highly recommend it!

The day after we returned home…

Fortunately, Maryland and climate change being what they are, it was 70F the following week…

To help with your next game of six-degrees of separation:

• Subo’s maiden name was Sobodhini Nagesan; she was Miss Sri Lanka 1977
• Dev Devendran knows Ranil Wickremesinghe and his family; we bumped into a nephew at the Royal Golf Club.

I used to like the Kindle platform and between Deana and I, we have purchased quite a few of them. Unfortunately, over the years, Amazon’s greed has ruined it and today, I’m done with the Kindle.

eBooks should be amazing. The zero-power persistence of eInk combined with cheap flash storage, wifi, and powerful microcontrollers should have made it possible to have an entire library in your pocket. The hardware is great, electronic distribution saves natural resources and, by nearly eliminating printing and distribution costs, eBooks should be able to lower book prices and give authors a higher share of sales.

The problem is that Amazon got greedy. Kindle editions now cost as much or even more than a real physical book, but much worse is that you can’t really buy a book for Kindle at all anymore, you can only rent it. I say you’re renting the book because you don’t own it in any meaningful sense: you can’t lend it or gift it to a friend when you’re done with it; amazon retains full control. Would you buy a car or a house that you couldn’t sell when you were done with it?

DRM – Digital Rights Management – is the technology that allows amazon to retain full control of a book that they’ve ostensibly sold to you.The solution might be to only buy books in the .epub format which does not include DRM (so you actually own what you’ve bought). You can read more about that here. Fundamentally, the issue is a legal concept called “first-sale doctrine“; you can read more about the eBook problem in this very good article.

Over time, Amazon has gradually raised prices and limited what you can do with a book you’ve “bought” until Kindle eBooks no longer make sense to me. It’s a great example of how monopolies hurt consumers: amazon owns more than 2/3 of the eBook market. Shame on amazon for ruining a good thing.