Saturday, February 17, 2024

My COVID-19 experience

I am seeing some improvement.  My experience with COVID-19 has been like a mild cold changing to a moderate cold, then to a severe cold, and finally back to a mild cold on the 5th day.  It appears that the Paxlovid has helped.  I am told that without it this can drag on for much longer.


Wednesday, February 14, 2024


I was trying to be careful and not catch COVID-19.  I was still practicing social distancing when possible, but I caught it anyway.  I don't understand how I got it, but it was either at a chess club or from going to Walmart.  I use the curbside pickup at Walmart, but sometimes I also go into the store.

I thought I would be immune because I am fully vaccinated, but the dominant JN-1 variant has a slightly different spike protein, sometimes bypassing vaccine immunity.  The latest vaccine was supposed to offer some protection from this variant.

Yesterday, I had trouble getting Paxlovid because my pharmacy was sold out.  I had to go to three different pharmacies to get it.  I took my first dose last night and my second dose this morning.  I have eight more doses to go.

Paxlovid is supposed to stop the virus from replicating, which would be very nice.  Any virus will grow exponentially until your immune system kicks in and starts destroying the virus.  The Paxlovid might help the immune system to win the war.

Yesterday, on my second day of COVID-19, I felt like I had a bad cold and could not get anything productive done.  I went to sleep at 10:30 which is early for me.  I woke at 5:00 AM feeling fully rested but wishing I had gotten more sleep.  I got up for a couple of hours, but when I started to feel tired I went back to bed.  I didn't think that I would be able to go back to sleep, but I got just enough of a nap to make me feel better.

I can tell that there is a battle going on in my body.  Either the immune system will win, or the virus will.  So far, I feel better today than yesterday, so maybe my immune system is working.

Best wishes,

John Coffey

Friday, February 2, 2024

Diamond Mike 1985 by JRC Software Played on Real NTSC Timex Sinclair 2068 Computer

I'm the author.  I thought the game was lost forever, but David Anderson found a copy.  I still have the Atari ST version I wrote in 1986, but I gave away all my Sinclair stuff (to my cousin who is no longer with us) when I moved to Utah in 1993 to work for the video game developer Sculptured Software.

The way you get through the 4th screen is to move right picking up diamonds while avoiding enemies.  Then you do the same thing on the lower level moving left.  The early levels are designed to be simple to teach the user how to play the game.  I think that some of the higher levels are more interesting.

There are no bonus screens.

Most of the time you don't have to hold the button to grab diamonds, but run through them.

I had better results playing the game with the keyboard.  

I also have trouble running the game under emulation.  I plan to try to find a workaround if one exists.  I think that it has something to do with reading the keyboard not working correctly under emulation.

"Compass" was a compiler-assembler that I wrote.  GGS was "The Great Game and Graphics Show" which was more of a demo of graphics and simple games.  In hindsight, I shouldn't have sold this as a product but offered it as a free demo.

Yes, the game uses the sound chip on the 2068 that wasn't available on the original Spectrum.

The multiple explosions at the end are technically a bug.  I expected the user to hit 'N' to advance to the next screen.  I should have made that automatic.

Friday, January 26, 2024

Push to 3000 on puzzle rating

The puzzle ratings on don't correspond in any way to USCF ratings.  I complained about this to, but they responded that their puzzle ratings are where they want to them to be.  (BTW, the upper limit on puzzle ratings is ridiculously high at around 32768.  Some people have actually reached this limit.  For computer nerds like me, this matches the upper limit on a 16-bit signed number.  This tells me that they are using 16 bits to store ratings in their database.)

I wanted to see if I could push my puzzle rating up to 3000.  I've been there before, but it is a hard rating to maintain.  

My puzzle rating averaged around 2935.  At this level, I am almost as likely to fail to solve a puzzle as I am to succeed.

I had a theory that if I did enough puzzles I could reach 3000 through a "random walk".   The idea was that if I bounced up and down enough I would eventually hit 3000 through random variation.  This wouldn't mean that I deserve to be at 3000, but got lucky.

It appears to me that will present puzzles with a sizeable range of difficulty.  This is where luck plays a factor.  However, every time my rating would creep up, I would face problems that seemed too difficult.  This definitely took me out of my comfort zone.

It took me about 2.5 hours to reach 3000.  However, to get there I had to analyze at a deeper level than I am used to.  Whereas the simple chess problems on my website are designed to build pattern recognition, it seems to me that the puzzles on are more of a measure of how well a person can analyze.  However, pattern recognition is still a factor.


Tuesday, January 16, 2024

Fwd: Pitfall of Extrapolation


On Mon, Jan 15, 2024 at 12:14 AM Albert wrote:
Hi John,

Sometimes you run into something that's interesting but you realize that most of your friends either don't care or don't get it. Well, this YouTube video was one of those interesting things. You're the only person I could think of who would find it interesting. I have to start looking for some more smart friends or at least curious friends. lol

On Tue, Jan 16, 2024 at 7:53 AM John Coffey <> wrote:
I saw this one.

I am pretty mathematical.  I found it interesting, but not enough to figure out the reason.

---------- Forwarded message ---------
From: John Coffey <>
Date: Tue, Jan 16, 2024 at 8:11 AM
Subject: Re: Pitfall of Extrapolation
To: Albert 

I was dumb enough to watch the full video here:

This involves math slightly above my level and lacks relevance to my life.  

Sometimes math goes so far down the rabbit hole that it feels like naval gazing.

I often thought that I should have been a math major.  It would have been more interesting to me than my biology major and fits in well with computer programming.

Wednesday, January 10, 2024

Why did Kids Stop Walking to School?

For most of my school years, I walked to school.  During High School, I had to take a bus, but if the weather was pleasant, on rare occasions I would walk the mile and a half home just because I liked to walk in good weather.

Tuesday, January 2, 2024

Early Internet

Around the year 2000, I was serving on the board of directors for the Utah Chess Association. We were considering abolishing our state chess newsletter and making a website instead. I pointed out that most people didn't have Internet access yet, but we expected that to change. (In fact, someone had set up a chess hotline with an answering machine, where you could call the phone number to get the latest state chess news.)

It was roughly 20 years ago that I switched from using dial-up Internet to the long-anticipated cable Internet. Getting 3 Mbps was a significant improvement over the roughly 100Kbps I had.

In the early days using slow dial-up modems, like 1200 bps, you would sometimes try to load a web page and get up and do something while the page was loading. I did this all the time.  It was so bad that there were optional programs that would download pages ahead of time so that you didn't have to wait for them to load.

Twenty years ago, just a few websites had video, but because of the limited bandwidth, those videos would occupy only a tiny part of the screen and be very low resolution. Apple's video format, Quicktime, was invented to help deal with low bandwidth.

YouTube was created in 2005. The first videos were at best "Standard Definition", which means that they were low resolution. I don't remember for sure, but the first videos might have had a resolution half that of Standard Definition, or roughly 240 lines. It would take years for Internet speeds to improve so that YouTube could offer higher-resolution videos.

Wednesday, December 20, 2023

Randy Linden Interview (THE MAN BEHIND DOOM SNES)

1:14:31   I am grateful that Randy keeps bringing up my name in these interviews.  My role was minor since I worked on many projects.  I don't remember specifically editing levels, but it was so long ago that I don't recall.  I know that we were trying to reduce the size of the game to fit on a cartridge.  I believe that I was involved in massaging the data, which is something I did on multiple games, especially Dirt Trax FX.

Sunday, November 5, 2023

Friday, November 3, 2023

Family Affair - Johnny Whitaker

I grew up watching this show. Brian Keith Sebastian Cabot, and Johnny Whitaker also appeared in other shows and movies. I was a fan of Johnny Whitaker who was roughly the same age as me. He played the titular character Tom Sawyer in a 1973 movie that got good reviews.

I assumed that people would be aware of these actors, but two of my friends who were both born in 1971 never heard of the show or the actors. It was before their time.

I was a fan of many shows from the late 60s and early 70s.

Best wishes,

John Coffey

Wednesday, November 1, 2023

Black Friday

The last time I tried to go to a Black Friday sale, it was so crowded that I couldn't navigate inside the store. Then I went home and just ordered what I wanted online. This is what everyone should do.

Best wishes,

John Coffey

Saturday, October 28, 2023

Minisforum UM790 Pro 7940HS Mini PC

My new (mini) computer has impressed me so far. On paper, it runs five times faster than my 2017 iMac. Although certain apps, like chess-playing programs, don't run five times faster (because adding more cores does not produce a linear improvement), the computer is a multitasking beast. Not only does it have 8 processor cores, but hyperthreading gives it 16 logical cores. I have tried to slow it down by having 14 cores doing computationally intensive tasks, and the computer handles it with no problem.

This is a different experience than my 2017 iMac which would slow to a crawl if I tried to do something computationally intensive on all four cores. (I'm not sure if some of this improvement is due to Windows 11. I noticed that Windows 10 uses a lot of CPU power just for the Operating System and so far that is not the case with Windows 11.)

I've seen some evidence of thermal throttling if I push the processor, but it is not bad. The fan can get a little noisy. Hypothetically, if the same processor were in a bigger case it could have a better cooling system and maybe be overclocked.

It might be a different experience if I were gaming which is one of the features of the Ryzen 9 7940hs processor, because it has the graphics cores built into it. There is no need for a separate graphics card, which makes the computer cheaper, but it will not be as good as a $1200 to $1500 gaming computer.

I saved $60 by ordering it from Ali Express (in China), but then I had to wait five weeks for it to get here. Now the manufacturer has a Halloween sale with $60 off, but the company is also in China. However, Amazon also has it listed for $60 off.

Monday, October 23, 2023

Slow Windows 10/Minisforum UM790 Pro

Has Windows 10 gotten slower lately? I noticed the same thing with Mac OS. This could be due to security updates, which put more burden on the computer. In addition, Windows Defender sometimes runs in the background making the computer slower.

In late May I had problems with my 2017 iMac and had to reinstall MacOS and Windows 10. During the repair process, I used my somewhat slow laptop as my main computer, but I was impressed at how well it ran Windows. However, I tried the laptop the other day, and it seemed sluggish. I also noticed that the iMac was sluggish.

Fortunately, I recently bought a new mini-computer. It uses the recently released 4-nanometer AMD 7940hs processor with a whopping 8 cores and 16 threads. Compared to my other computers, it is ridiculously fast. This is also my first computer that uses SSD for storage. SSDs are very fast and have been around for a while, but they became much more affordable this year.

I waited for the computer to go on sale and ordered it from China to save money. However, I had to wait 5 weeks for it to ship from China. I just noticed that it is on sale on Amazon.


Sunday, October 22, 2023


Although it is hard to know for sure, I think that my long-term memory is extremely good. I remember details from decades ago. I am astonished by the passage of time because events from the 60s, 70s, and 80s don't seem that long ago to me.

My mother passed away a week ago. I have a ton of good memories of her, and this comforts me a little.

Best wishes,

John Coffey

My mother's funeral was Saturday

I tried to send this email from my phone yesterday, but neither the phone nor Gmail has a record of it.  It is like the phone had a glitch and deleted the email.

My mother's funeral was on Saturday.  It went well.  

It was a fitting service for someone as nice as her.  She was a kind and caring person who I loved deeply.  I hated to see this happen to her.  

I'm coping with the loss.  Almost everyone has to deal with the death of their parents.

Best wishes,

John Coffey

Tuesday, October 3, 2023

Monday, September 25, 2023

Diamond Mike – Timex/Sinclair Computers

This is a videogame I wrote in 1985.  I thought that it was lost forever.  I had given away my Timex Sinclair stuff to my cousin when I moved to Utah in 1993.  I wish that I had kept it.  She said that eventually the computer died.

I contacted the website manager and asked him to look out for the game. He not only found a copy but sent me the tape from 38 years ago!

He made a downloadable online version.  I tried to run it using an emulator.  With the emulator, I was having trouble getting the controls to work.

The Atari ST version I wrote in 1986 looks better but is essentially the same game.  I have a copy of this, but no hardware to run it on.

I made money on this stuff in the mid-1980s but eventually had to get a real job.

Saturday, September 23, 2023

DF Retro: The Making of Doom on Super NES - The Original 'Impossible Port'...?

34 minutes ago 
19:07 "More Romero, less Coffey." 

Randy said that I edited levels and did game testing, but it was so long ago that I literally don't remember any of the details. I have since worked on many projects and for different companies. Video game companies have a habit of going out of business, so I ended up working for a major military contractor and eventually retired from there.  In my retirement, I'm trying to learn app programming. 

If we edited Doom levels, I don't remember how we did that. I do remember being a Doom fanatic. I still love the game. 

What I think I remember is that we were trying to edit the levels to save space to fit on a 2 MB cartridge, but ID shot this down. I could be wrong. 

I was impressed that Randy was able to port the game to the SNES. 

The company we worked for was tight on space.  My office was a former supply closet, which didn't bother me.  All I needed was a table and a computer.

Wednesday, September 20, 2023

My 7940hs computer order

The problem with trying to order from Ali Express to save money is that they can slow to deliver the products. My past purchases took between 2.5 to 5 weeks to arrive.

I ordered this computer four weeks ago today. They claimed that they were offering a guaranteed on time delivery of a week ago.

Friday, September 15, 2023

My computer order is delayed (due to COVID?)

This is what I get for ordering from China.  I ordered from Ali Express to save some money. 

However, the manufacturer is in China anyway.  I could have ordered from the manufacturer and still faced the same delays.

I ordered this computer 23 days ago. The estimated delivery day was September 12th. There has been no tracking information, although the Ali Express app claims that the computer is still in China and that there are delays.
Do you have any information about if the computer has left China or when it will be delivered?
This was advertised as "Guaranteed On Time Delivery." This led me to believe that the delivery would take 3 weeks.
发货提醒客户好评: Hi Dear, We send your order out earlier and update tracking number already. Due to serious COVID-19 epidemic in Shenzhen and Hongkong, transit and tracking info updating will be delayed. Thanks for your patience and cooperation. Hope you can give us 5 stars feedback with pictures if you are happy with our product. Please contact us if you have any problems before leaving negative feedback. We will serve you to satisfaction. Thanks. Best regards

Tuesday, August 22, 2023

Computer Ordered

Ali Express has a sale that started last night.  This computer usually sells for $700.

I am buying another computer because this new model has a new 4-nanometer chip that is five times faster than my 2017 iMac.  For some tasks like compiling code, my iMac seems slow.  The new computer uses an AMD APU that has the graphics built into the CPU.  This makes it just good enough for playing games without having to buy a graphics card costing hundreds of dollars.

I already bought a 27-inch 1440P monitor to use with this computer, which I got off of Facebook Marketplace for $50.  I had to drive all the way to Noblesville to get the monitor.

I have been wanting a powerful AMD APU ever since new video game systems came out in 2019 featuring powerful custom AMD APUs.  It took them this long to come out with a powerful AMD APU for home computers.

Saturday, August 5, 2023

When I Landed In America I Understood That We Never Had A Chance

I found the story of this German POW very compelling.   I was so caught up in his story that I listened to the end, which had a nice finish.  That's about 6 hours of audio. 

This starts as the 11th video of a 16-video playlist.  However, parts 13, 14, and 15 drag on a bit as they talk about his life as a POW.

Sunday, July 30, 2023

Re: The tale of four displays

BTW, it only took me about 5 hours to sell the unwanted monitor on Facebook Marketplace.

Saturday, July 29, 2023

The tale of four displays

I bought both used computer monitors with the intention of comparing them and selling one.

The 4K monitor appears to have more washed out colors. Faces are more pale. The Star Wars crawl is yellow orange on the 1440p monitor, but pure yellow on the 4K monitor.

The color on the 1440P is closer to my 5K iMac display, which is reportedly a high quality display, and has a slightly better viewing angle than the 4K monitor.

I had all three displays playing the same movie at the same time.

So I just compared the cheap 40 inch TV that I originally purchased for my Mom and stepdad, but I am now using as my TV. It appears to have the same washed out color range as the 4K monitor.

I would have never known the difference had I not compared these side by side.

This makes my idea of using a cheap TV as a computer monitor look bad. The color quality might not matter as much for watching television, but depending upon what you do with it, I think that it matters more for a computer monitor.

Best wishes,

John Coffey

Friday, July 28, 2023

Missed Amazon Prime Day TV deal

During Prime Days, Amazon had this special deal that was invitation only. You had to sign up to be invited. The deal was for a 43 inch Amazon Fire smart 4K TV at $99. Of course, quantities were limited.

I'm kicking myself for not getting the deal.

According to the specs and reviews, the latency and color accuracy of the TV was a little less than ideal for use as a monitor, but I felt that it was good enough. I don't think that something like a 20 millisecond latency is going to be much of a problem.

I like the idea of having a 43 inch 4K monitor that is also a TV.

It would have saved me much trouble that I recently went to in order to buy a couple of used (high-quality) monitors. The 4K 28-inch Samsung monitor I bought only has 1-millisecond latency.

During Prime Days I was not feeling the best, although I've been feeling better lately.

Best wishes,

John Coffey