Peter's Blog

Just commenting on things that interest me

Category: Technology (page 1 of 2)

One Small Step for a Man

On this day 50 years ago, man set foot on the moon.

It still seems incredible to me that in 1969 it was possible for three men to take off from the earth, navigate to the moon, land on the moon, take off again, and return to earth successfully!

If we had not done that 50 years ago, and we were setting out to do it today, I would still be impressed!

But I guess the thing that astonishes me most, given all of my years in computing, was the “Apollo Guidance Computer (AGC)”. This computer had 36k words of ROM and 2k words of RAM, weighed about 70 pounds(about 31kg ), was accessed using a calculator-style keyboard and display (called a “DSKY”), and “flew most of Project Apollo except briefly during lunar landings”!

That is amazing to me. The astronauts gave it instructions using a 2 digit verb and a 2 digit noun!

Apparently the power of the computer was comparable to an Apple II (which I had about 8 years later).

And apparently the “software development on the project comprised 1400 person-years of effort, with a peak workforce of 350 people”. At its peak, the Apollo program employed 400,000 people apparently!

In 2009, a DSKY (just the interface, not the whole computer) was sold in a public auction for $50,788 (about €45k)

It’s no wonder some people believe that the Apollo moon landing was faked. It’s an amazing achievement.

I was 7 when the mission took place. I remember looking at the fuzzy pictures on a TV. I’d like to say it was in black-and-white but we were on holidays at the time and I think the TV we were looking at had some kind of green filter!

Here is a link to the Wikipedia page for the AGC:

And here is the photo from the Apollo 11 mission with which I am most familiar (it was in the volume of encyclopedias we had at home when I was growing up!)

Hilarious Robot Video

A company called “Boston Dynamics” has built a very impressive robot called “Atlas” and has made the following video to demonstrate some of its capabilities:

Then some genius came along and added a new soundtrack to make this completely hilarious video. Funniest thing I have seen in ages. Enjoy!

Another Big Apple (Steve Jobs) Mistake

In my last post, I mentioned a small mistake made by Apple/Steve Jobs.

Here is a much bigger one, and one which has never been rectified properly.

The reason I don’t have an iPhone, and don’t ever plan to but one, is that it is too “closed”.

I have an Android phone and I can program it using “MIT App Inventor“. This simple tool (which I teach kids in CoderDojo) allows you to create apps, to transfer them to an Android phone, to debug them interactively, and to create apps which can be uploaded to the Google Store.

App Inventor is not available for iOS because Apple (and I believe this to be a Steve Job legacy) doesn’t want people developing code any way but the “right” way. And the right way involves Xcode, Objective-C or Swift, a Mac, possibly other tools, and registering as (and paying to be) an iOS Developer. And for the longest time they didn’t want you to do any kind of coding on an iPhone/iPad (this restriction has been eased more recently with things like Codea, ScratchJr, Pyonkee and “Swift Playgrounds“).

I mentioned this restriction previously in my old blog when I spoke about “Cargo-Bot“.

So until this is addressed, I’ll be sticking with Android.

Another Apple (Steve Jobs) Mistake

Here is another (very small) mistake which Jobs made: He thought a mouse should have one button (so as not to confuse users, apparently). He did not want users to have to “right click”.

So Lisa, IIGS, Mac, etc. all came out with a single button.

To me, this was just wrong.

Over time, Windows mice had two or three buttons and maybe a “wheel”. This obviously gives the user more power.

And then he endorsed the idea of a mouse with no buttons! This article claims that this came about through a misunderstanding.

I guess the problem was addressed eventuality with the multi-touch “magic mouse”. But I don’t know for sure as I have never used one.

Here is a picture of original Macintosh mice:

Mac Mouse

Apple’s Biggest Mistake

I mentioned the Apple IIGS in my last post.

I came across an interesting video on YouTube entitled “Apple and Steve Jobs’ Biggest Mistakes Ep 1 – The Macintosh”.

This interesting video claims that the original Mac was a mistake. I don’t think anyone would disagree with that. The YouTuber (“The 8-Bit Guy“) goes on to make a compelling argument that Apple should have promoted the Apple IIGS and dropped the Mac.

Here’s the argument:

  1. The IIGS was superior to the Mac in a number of areas (e.g. better sound and graphics)
  2. It was more extendable (slots for cards)
  3. It was a lot cheaper

And the amazing (and cool) thing about the IIGS was that it was able to run most of the Apple II software. So there were hundreds upon hundreds of software products available for it! (Compare this with the Mac which suffered from a horrible lack of software).

He argues (and I agree) that Apple should have been pushing the IIGS rather than the Mac (he blames Steve Jobs for this decision which, based on everything we know about how Jobs was behaving at that time, seems reasonable). But instead they reduced the CPU speed of the IIGS on purpose to make sure that GUI (which was very similar to the Mac’s but in colour!) was sluggish and unable to match the Mac!

Wikipedia tells us that ” The machine outsold all other Apple products, including the Macintosh, during its first year in production”.

We are left to wonder how things would have turned out if Apple had not crippled the machine and has pushed it instead of the Mac. They might have been able to avoid all of those years in the wilderness. Maybe it could even have given the IBM PC a run for its money! Imagine if we were all running machines now which were descended from the Apple II rather than from the IBM PC!

The video includes “Ep 1” in the title and “The 8-Bit Guy” says that he plans to talk about other mistakes which Jobs made but I can’t see any sign of such videos.

You can see the video here:

Steve Wozniak – Genius

In my last post, I spoke of my admiration for a man who build a computer because he did both the hardware and the software.

I cannot leave this without mentioning my undying admiration for Steve Wozniak.

“Woz” designed and built both the Apple I and the Apple II (the first computer I every owned). As if that wasn’t enough, when you look at the “Apple II Reference Manual”, you can see from the listings that he also wrote the following programs in assembler:

  • The operating system (“System Monitor”) with Allen Baum
  • The Mini Assembler again with Allen Baum
  • Integer BASIC
  • The Floating Point Routines
  • The “Sweet16 Interpreter”

He also wrote some of the BASIC games such as Breakout (which he didn’t put his name on) and Mastermind (which he did).

He went on, of course, to design printer interfaces, serial interfaces, the floppy drive and later contributed to the Apple IIGS.

I found his book iWoz in the local library some time ago. It is a very enjoyable read. I found myself very jealous of the place and time where he grew up.

There are lots of views featuring Woz in YouTube. Here is his appearance on Conan in 2016:


Building a REAL Computer from Scratch

In my last blog I spoke of my admiration for a man who built a simple working computer using TTL chips. This computer is fantastic for teaching/learning how computers work.

Imagine, therefore, my admiration for a man who built a REAL computer using TTL chips. By “real”, I mean that it:

  • Runs a port of the MINIX operating system
  • Is multi-user and multi-tasking
  • Is connected to the Internet
  • Has a front panel with loads of LEDs and switches (like me, Bill believes that this is crucial)
  • Users can Telnet on to it over the Internet!

The creator, Bill Buzbee, is a genius. He did both the hardware AND the software. He says that he did it because he wanted to learn more about hardware. He certainly did that, including learning how to “wire wrap”.

The software includes:

  • C compiler, Assembler, Linker
  • TCP/IP stack
  • A set of utilities
  • A set of games

Bill had to do EVERYTHING – even creating his own instruction set! It’s an amazing accomplishment.

Only one user can Telnet onto the computer at a time, but I managed to do so the other day. It’s incredible to think that that I was running a game on a computer which someone has built and programmed all on his own!

Here is a video of the computer “coming alive” (as Bill puts it) in 2004.

And here is a link to his YouTube channel.

And here is a long (almost an hour) video where Bill explains everything about the computer, which he calls “Magic-1”:

Building a Computer from Scratch

I have huge admiration for people who build their own microcomputer using a microprocessor. So imagine the admiration I have for people who build a computer WITHOUT using a microprocessor!

One such guy is Ben Eater.

He has a series of videos on YouTube which show how to build an 8-bit computer on breadboards using TTL logic! The videos cover everything from building the clock, to registers, to the Program Counter, to RAM, to the ALU, etc.

It is really cool and he explains it all very clearly. So if you want to understand how computers work at a very low level, I can’t think of a better resource.

Here is a link to his YouTube channel.

He also has videos which explain lower-level concepts, such as how diodes and transistors work, and how they can be used to build “gates”, etc. work. He explains everything very slowly and calmly. Here is a link to his video on “How Semiconductors Work“. I can honestly say that nothing has helped me to understand this topic as well as this video did.

My hat is off to you, Mr Eater!

And here is a video where the man himself is interviewed:

Cosmac ELF

I mentioned in my old blog how taken I was by a very simple microprocessor-based microcomputer called the Cosmac ELF, dating back to 1976.

The microprocessor in question was the RCA 1802.

The microcomputer was really just for learning about computers. You could enter short programs via switches and then run them. To blink LEDs or whatever.

I have been thinking about this again recently and I have been amazed how much interesting stuff there is about this device on YouTube.

Here are some short videos showing people using their ELFs:

Entering a short program with commentary by DevilishDesign

Entering a short program by hvman

The ELF in this short video has some enhancements including the video interface from a subsequent “Popular Electronics” magazine:

With a display by Les Wright

There are other videos on the “Cosmac ELF 2000” and the “Cosmac ELF Membership Card”.

Then this is this long (46 mins!) video by youtuuba where he discusses exactly how he built his ELF:

Unexplained Music

For some time now I have been experiencing a strange phenomenon on my laptop: at odd times it has suddenly started playing music. It would always be the same music – some kind of instrumental which I could not place. The strange thing was that it was playing more than one copy of the musics at the same time, generating a strange cacophony.

I worked out that it would only happen when Firefox was open – something which I was able to verify by using the Volume Mixer when it was happening.

I searched on the web thinking that it must have happened to someone else but no luck.

I finally worked out what was causing it and I thought I would share it.

I stalled a Firefox extension called “Distil Web Monitor” and I configured it to watch a particular web page for changes (I was waiting for their 2016 price-list to be released).

I was monitoring 3 versions of the page (in 3 different languages).

Each version of the page includes a video. This video is normally muted by default. Here is the HTML which is used to embed the video:

<video autoplay="autoplay" muted="muted" loop="loop" poster="videohome/COMMERCIAL_SHORT-G.jpg" style="width:100%" title="">
		<source src="videohome/COMMERCIAL_SHORT-G.m4v" type="video/mp4" />
		<source src="videohome/COMMERCIAL_SHORT-G.webm" type="video/webm" />
		<object type="application/x-shockwave-flash" data="videohome/flashfox.swf" width="164" height="92" style="position:relative;">
		<param name="movie" value="videohome/flashfox.swf" />
		<param name="allowFullScreen" value="true" />
		<param name="flashVars" value="autoplay=true&amp;controls=true&amp;fullScreenEnabled=true&amp;posterOnEnd=true&amp;loop=false&amp;poster=videohome/COMMERCIAL_SHORT-G.jpg&amp;src=COMMERCIAL_SHORT-G.m4v" />
		 <embed src="videohome/flashfox.swf" width="164" height="92" style="position:relative;"  flashVars="autoplay=true&amp;controls=true&amp;fullScreenEnabled=true&amp;posterOnEnd=true&amp;loop=false&amp;poster=videohome/COMMERCIAL_SHORT-G.jpg&amp;src=COMMERCIAL_SHORT-G.m4v"	allowFullScreen="true" wmode="transparent" type="application/x-shockwave-flash" pluginspage="" />
		<img alt="COMMERCIAL SHORT-G" src="videohome/COMMERCIAL_SHORT-G.jpg" style="position:absolute;left:0;" width="100%" title="Video playback is not supported by your browser" />

So what must have been happening was that, at regular (but seemingly mysterious) intervals, the extension was going out to fetch the 3 pages to look for changes and, when this happened, all three versions of the video started to play but they were not muted!

So I removed the 3 pages from my Distill extension (the new price-list is out now) and the problem has gone away.

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