The Wednesday Morning Crash Bug

I have a problem with my computer that is stumping me. The first time I start it on Wednesday mornings, it runs about 8 minutes and then it locks up. Screen freezes, no input is capable from the mouse or keyboard. Once I restart the computer it will happily run for another 6 days and 23 hours, then it’s back to lockup.

Last month I started my bug chase in earnest. I scrubbed event logs and can’t really find a source. I get unhelpful responses like this when I look at event viewer:

My assumption is that some process is phoning home on a schedule, then attempting to do something and locking up at that time. My most likely villain is Window Microsoft Defender because I see WMI running around the same time and that seems to be part of how the home version manages it. I looked into changing the time for update checking, but that seems to be restricted to enterprise versions on the MS documentation I have read.

So, it’s at a place where I can live with it. I know it’s going to happen and when, so I can plan for it. It’s just annoying and seems like there should be a way to solve this. Some solutions I have ruled out:

  • I am not switching to Linux or another OS. I have things I need to access that will only run on Windows.
  • I am not switching anti-virus software. I can only imaging that will make it worse, not better.

If you have any thoughts on this, please send me a tweet to @N4BFR on Twitter and help with the conversation.

How Long for Long Pi – Part 4 – Bring out the Raspberries

In the 4th post in this series (find post 3 with Win-tel stats here) I broke out the Raspberry Pi collection to see how this device has changes over the generations. I can say for sure it only gets better.

In 4 generations the Pi performance has improved from almost 19 hours to calculate Pi to 1 Million Places to just under 4 hours. That’s a 80% performance improvement in 8 years. Now the price has gone up, the Pi 4 as I have it was $75 vs the $25 of the Pi 1, but 4 times faster for less 3 times the price over those same 8 years is amazing to me.

I take the Pi 0 W results with a grain of salt because that’s supposed to be a smaller, less powerful board. But it costs $10 new. If you want to compare them by their different SOC’s Wikipedia has a great article that has all the specs.

I’m still a big Raspberry Pi fan and I probably could do more with a single Pi than I do, but I have a dozen in this room and they just crank along like magic. I don’t have one favorite project but one that you might want to read about is my Flip Dot Clock.

Today I have some older Apple machines on the bench. I’ll share those results tomorrow.

How Long for Long Pi – Part 3 – Intel Machines

Following up on my How Long for Long Pi posts from Thursday and Friday I wanted to start quantifying the data a little more. I was able to gather data from 5 Intel computers. They are:

CPU TypeCPU GenerationForm Factor
Intel i712th GenerationHomebuilt Desktop
Intel i710th GenerationLegion Laptop
Intel i78th GenerationYoga Laptop
Intel i77th GenerationAsus ROG Desktop
Intel i77th GenerationYoga Laptop

My testing methodology was to run 3 passes of the test calculating Pi to 100,000 places via a Python 3 script (see Friday’s post) and then to 1,000,000 places. All 5 machines ran native Windows. (The Legion Laptop and 7th Gen Yoga are Win 10, the others Windows 11). On 4 of those machines I could dual boot into Ubuntu 20 Linux from a USB SSD drive.

I was surprised that the Ubuntu versions averaged 13.7% faster calculation time than the Windows machines. I don’t have the details to drill down further to attribute that to the overhead of the operating system or to efficiency of the versions of Python 3.10 or just something else entirely.

When you spend more time calculating, you find an even bigger difference in times. Ubuntu calculations were 28.3% faster at this length of calculation. The other thing that jumped out at me in both calculations was that a 7th Gen Desktop was faster than an 8th Gen Laptop (4.3% on Ubuntu 1 Million) While all these processors are multi-core, it appeared to me that all these were running in a single processor while calculating, using Task Manager on Windows and htop on Ubuntu.

Testing of all 5 versions of Raspberry Pi (0W, 1, 2, 3, 4) are underway. I’ve also got some other devices to test, and I was surprised to see a handheld device outperform one of the 7th Gen Intel machines at a Million places.

Again, please feel free to provide comments on my Twitter – @N4BFR.

How Long for Long Pi – Part 2

In a previous blog post I considered how I might benchmark performance of different computers to understand how they compare across processor generations and maybe in the future across major architectures.

After experimenting with some different Python code, I found a version that is very consistent in it’s performance, seems to run on 1 core of a multi-core processor and can run on Windows and Linux. Here’s the version I am using for calculating Pi to 100K. I sourced it from this Stack Overflow thread.

#-*- coding: utf-8 -*-

# Author:    Fatih Mert Doğancan
# Date:      02.12.2014

# Timer Integration 18-Jun-22 by Jim Reed

# Timer function Start
import time

start = time.time()
print("Dogancan - Machin 100,000 Digits Pi Calculation Start")

#Original Calculation Code goes here

def arccot(x, u):
    sum = ussu = u // x
    n = 3
    sign = -1
    while 1:
        ussu = ussu // (x*x)
        term = ussu // n
        if not term:
        sum += sign * term
        sign = -sign
        n += 2
    return sum

def pi(basamak):
    u = 10**(basamak+10)
    pi = 4 * (4*arccot(5,u) - arccot(239,u))
    return pi // 10**10

if __name__ == "__main__":
    print (pi(100000)) # 100000

# calculation code code ends
# timer reports

end = time.time()
print("Dogancan - Machin 100,000 digits elapsed calculation time")

I expect to share all my raw data as I get it more in shape, but I am definitely getting some good first impressions. Let’s look at a summary of the tests on 5 machines so far, running Pi to 100K places using the code above on Python in a command prompt / terminal shell.

My PC NamePC TypeOSPi to 100K in X Seconds
(Avg 3 Runs)
TelstarRaspberry Pi 3Raspbian148.395
EdisonRaspberry Pi 4 8GBRaspbian111.263
TeslaIntel i7-7th Gen DesktopWin 1112.997
TeslaIntel i7-7th Gen DesktopUbuntu 2010.960
Charlie DukeIntel i7-8th Gen LaptopWin 1113.342
Charlie DukeIntel i7-8th Gen LaptopUbuntu 2011.627
MarconiIntel i7-12th Gen DesktopWin 116.152
MarconiIntel i7-12th Gen DesktopUbuntu 205.352

No surprise here on machine power. The more powerful the machine, the faster it processed. Now, I don’t think I have enough samples or data to draw a strong conclusion, but on the machines where I could run Ubuntu and Windows, Ubuntu outperformed Windows by at least 12% when averaged across the three runs.

Now let’s step it up an order of magnitude. How long will it take these machines to calculate Pi to 1 Million places. I used the same Python script, just changed the variable. Note on this run because of the long run times, I only ran the Raspberry Pi tests ONCE, the 3 other PC’s show an average of 3x runs.

My PC NamePC TypeOSPi to 1 Million in HH:MM:SS
TelstarRaspberry Pi 3 (1 Run)Raspbian5:12:57
EdisonRaspberry Pi 4 8GB (1 Run)Raspbian3:42:01
TeslaIntel i7-7th Gen DesktopWin 110:26:08
TeslaIntel i7-7th Gen DesktopUbuntu 200:18:21
Charlie DukeIntel i7-8th Gen LaptopWin 110:27:44
Charlie DukeIntel i7-8th Gen LaptopUbuntu 200:19:11
MarconiIntel i7-12th Gen DesktopWin 110:12:25
MarconiIntel i7-12th Gen DesktopUbuntu 200:08:57

One of the really cool pieces of data was the difference in the Marconi runs on Ubuntu 20 was 0.14 seconds from high to low.

The difference in the Windows vs Ubuntu really stood out this time. Here’s the 3 machines data individually:
Charlie Duke was 30.46% faster with Ubuntu
Tesla was 29.78% faster with Ubuntu
Marconi was 28.84% faster with Ubuntu

So, ultimately, I don’t know if this will mean anything to anyone but me, however I am enjoying this so far. Next steps:

  • Complete Household Data Gathering – Will run on Pi 1 and Pi 2, a 10th Gen Intel Laptop and a 2105 Mac Mini
  • Publish my complete data set.
  • Understand if I can port this calculation. Ultimately I’d love to try one of the old museum Cray machines to see if I can add those to the scoreboard.

If you have comments or thoughts for me on this, you can tweet me @N4BFR.

How Long for Long Pi?

Note: This is less of a blog post and more of a running commentary on a project I have conceived. I have a long way to go on it but I hope you enjoy the journey.

I’ve been thinking about computers I have seen at places like The National Museum of Computing in the UK or the Computer Museum of America here in Metro-Atlanta. One of the things that has always challenged me is how to benchmark computers against each other. For instance, we know the Cray 1A at the CMoA had 160 Megaflops of computing power, while a Raspberry Pi 4 has 13,500 Megaflops of computing power according to the University of Maine. What can you do with a megaflop of power however? How does that translate in the real world.

I’m considering a calculation matrix that would use one of two metrics. For older computers, how many places of Pi can they calculate in X amount of time. Say 100 seconds? For newer computers, how long does it take for the machine to calculate Pi to 16 Million places. Here are my early examples:

Pi to 10,000 Places on Raspberry Pi

ComputerProcessorRAMElapsed TimeHow Calculated
Raspberry Pi Model 3ARM SomethingSomething6 Min 34 Sec
394 Seconds
BC #1 (Raspbian)
Raspberry Pi Model 3ARM SomethingSomething2 Min 15 Sec
135 Seconds
BC #2
Raspberry Pi
Model 3
ARM Something0 Min 0.1 SecPi command

Pi to 16,000,000 Places

ComputerProcessorRAMPi to 16M Places TimeHow Calculated
Lenovo Yoga 920Intel Core i7-8550U CPU @ 1.8 GHz16 GB9 Min 55 Sec
595 Seconds
SuperPi for Windows Version 1.1
Lenovo Yoga 920Intel Core i7-8550U CPU @ 1.8 GHz16 GB0 Min 23 SecPi command
N4BFR Vision DesktopIntel Core i7-12700K CPU @ 3.6 GHz32 GB3 Min 15 Sec
195 Seconds
SuperPi for Windows Version 1.1
Raspberry Pi Model 3B+ARM 7 Rev 4 (V71)1 GB6 Min 03 Sec
363 Seconds
Pi command

Tools I am considering to use will be an issue because I want consistent performance across operating systems. Efficiency will be an issue because I will want something that computes at roughly the same speed for windows as for Unix.

  • SuperPi for Windows 1.1 was the first I came across and it seemed to be pretty straightforward that would run on many versions of Windows I came across.
  • Moving on to a calculator I could use in Unix, I found this John Cook Consulting Website that had a couple of calculations using the BC program. I found the results inconsistent on the Lenovo Yoga 920
BC Calculation 1: time bc -l <<< "scale=10000;4*a(1)"

BC Calculation 2: time bc -l <<< "scale=10000;16*a(1/5) - 4*a(1/239)"

I then found the Pi command on pi that might be more consistent with what I need.

$ time pi 10000

Pi Calculations on Lenovo Yoga 920
Windows time is reported by SuperPi. BC time is “Real” time reported by process.

Pi Calculated to X Places. X=Windows TimeBC `BC 2Pi Command
10K (Pi Compairison)1 Min 45 Sec0 Min 32 Sec
0 Min 35 Sec
0.09 Sec
20 K3 Min 22 Sec0.
50KIncomplete after 15 minutes
128K0 Min 01 SecIncomplete after 60 Minutes
512K0 Min 08 Sec
1 M0 Min 16 Sec
8 M3 Min 05 Sec
16 M9 Min 55 Sec0 Min 23 Sec

So using BC as a method of calculating does not seem to scale.

Coming back to this a few days later, I may have a partial solution. This will limit the use of this on older machines, but should be fairly consistent with newer ones. I plan to do the calculation with a script in Python 3. This should allow for roughly similar performance on the same machine to make results more comperable.

Python3 Downloads:

Python3 methods for calculating Pi:

I was able to get a rudimentary calculation in Windows using both of the formulas and include a function to time the process consistently. Now I need to compare in Linux and blow out the calculation to allow a material number of places for this to be an effective measure.

I have found a few more options thanks to StackOverflow and I’m testing them now on my 12th Gen Intel machine.

  • 100,000 digits of Pi using the “much faster” method proposed by Alex Harvey: 177.92 seconds for the first pass, 177.83 seconds for the second pass. I like the consistency
  • Guest007 proposed an implementation using the Decimal library. I attempted a 10,000 digit calculation and that took 24.6 seconds, 100,000 places didn’t complete after more than 10 minutes. Interestingly, a peek at the system processing said it was only running 8.1% of CPU time.

Tomorrow I’ll start a new chart comparing these two methods across multiple machines.

Researching Sgt. Clemett Harrison Saint

Sgt. C.H. Saint’s gift from the town of Horden for being awarded the Military Medal during WW1.

I’m enjoying looking more and more into my family history and today I am spending a few minutes on C. H. Saint who hailed at one time from the village of Horden, England in County Durham. Great Granddad Saint was given the Military Medal in 1918.

Here’s what has to say about Sgt. Saint

Born in Marsden Colliery, Durham, England on abt 1890 to John Thomas Richardson and Dora Harrison. Clemett Harrison Saint married Rose A Salmen and had 1 child. He passed away on 21 Mar 1937 in West Hartlepool, Durham, England.


I found this at the UK National Archives site. It appears he fought in Egypt during the war, in the British Army’s Durham Light Infantry.

I’m hoping to visit Hoden in the fall to see what else I might find out.

Telstar and Callsign Curiosity

Note: Initial post of this article was around 5 PM on April 20, 2022. I corrected the post around 6:20 to reflect the proper call sign.

In case you didn’t know, Telstar was the first satellite to do communications between 2 continents. It launched in June 1962 and lasted less than 9 months.

YouTube was nice enough to suggest this Periscope Film called “Behind the Scenes with Telstar.”

This left me with a few questions:

At 27:08 in the video the tech says “sending station identification” and you hear in Morse what appears to be DE KF2XBR.

Correction from initial post: I found a second video where you can hear the Morse Code and it’s clearer now. The call sign is KF2XCK as found in the linked video from AT&T Tech Channel.

I don’t know that satellites to this day that satellites have had their own callsigns, so I’m assuming this is the ground station call sign. That ground station was in Andover, Maine. (An additional Bell Labs Telstar video confirms at least the DE KF portion of the call.)

This raised a couple of questions for me. If it was a communications service, why didn’t it have a XXX#### type call that seems to have been given out at the time?

Why was if KF2*** when Maine is in the 1 call sign area? My guess is that KF2XBR would have been assigned to Bell Labs, and that would have been coordinated out of their New Jersey HQ. I looked at the 1961 and 1963 Call Books, but there are no K*2X* stations listed.

I’ll be doing more research but if I am to believe Wikipedia, all experimental call signs, not just amateur, were in this **#X** format.

I did find a later use of KF2XBR as part of a BellSouth permit granted by the FCC in 1990. These look like cellular telephone frequencies.

From reading through these FCC proceedings, it might say that these experimental calls were given out sequentially instead of by call region, because many of the calls listed were KF2X** calls.

An interesting fact I found when reading was that the US accidentally nuked the satellite after a high altitude nuclear test. Scientific American documented how the Starfish Prime test impacted Telstar, which launched a day later.

Upcycling to make the SpaceX Gate Sign

Back in January found an 80’s vintage airline gate sign in an antique store and decided to upcycle it into something that would fit in my tech center redesign.

Poor sign all unwanted.

I introduce the SpaceX Gate sign.

The sign was supposedly a Piedmont Airlines sign from Newark. It had no power or instructions but I knew I could get past that. Two power bricks later and the LED’s were working great. I reached out to the manufacturer but no luck on getting a manual. I powered along.

I reached out to AlphaGraphics in Dunwoody where one of my former co-workers had set up shop. They were great in going back and forth with me to get the sign elements just the way I wanted.

There are 4 possible “vehicle” inserts. Crew Dragon, Falcon 9, Falcon Heavy and Starship. There are 4 possible “gate” inserts, 39A at KSC, Pad 40 at CCSFS, Pad 4 at Vandenberg and Starbase, Texas. Here’s an example:

Prepared for the future!

I plan on updating this with the latest manned mission info, which is currently NASA Crew 4 as shown. The LED’s are updated with a slide out keyboard on the right.

You can see this in action and the entire build in a video on my N4BFR Vision You Tube page:

What do you think? Leave feedback on YouTube or tweet me @N4BFR.

Catching up on my YouTube Channel

I’ve been loading up YouTube lately with videos I have shot on the road. Here’s the latest:

I love this 4K time lapse with the natural sound of a sunrise in the park. There’s also a longer version for nature lovers.

I was lucky enough to be one of the operators for the W5B ham radio special event. Here’s what it looked like at the studio building.

I decided to spend some time fixing up a clock I got a great deal on. Here’s the first of 3 videos showing the fixup.

There are also a bunch of new shorts and some ham radio operating videos when you go to N4BFR Vision on YouTube.

Xiegu X108G HF Transceiver as a Shortwave Receiver

I purchased a Xiegu X108G HF Transceiver at the Dalton Hamfest from an estate seller. The radio appeared to be lightly used and in it’s original foam shipping container. I connected it to my LiPo battery and my dipole HF antenna to check reception. This video shows WWV on 10, 15 and 20 Mhz. All three frequencies were coming in to my location nicely on this Sunday morning.

My goal is to build this into a small kit with a battery and end fed antenna that I can keep in my car for when the POTA bug strikes me on road trips.

First impressions:

Sounded fairly good when warmed up. On first power up, I was picking up RFI bleeding in at 15 Mhz from a local broadcaster, whose transmitter is 6 miles away as the crown flies on 680 Mhz. That seemed to fade out as I switched around between the bands. I also toggled the preamp on and off, so I can’t isolate what the culprit is.

The best control of the radio seems to be from the Icom like microphone. I could switch bands, directly enter frequencies and try different modes like AM vs USB. I wasn’t impressed that USB was set to a 2.3 Mhz bandwidth by default, I prefer 2.7 so this was a little narrow.

The power on screen listed firmware from 2017 so I will be looking for options to upgrade that. It did not remember the frequency I was on when I turned it off and on, instead defaulting to 14.270 Mhz and LSB.