Categories
Science

Rebooting the Apollo Guidance Computer

If you can’t get enough of the Apollo missions after my last post watch as the Apollo Guidance Computer (AGC) is booted up. See inside the machine at the ropes used to store information and marvel at all the little wires that made the landing on the Moon possible.

For more check out this playlist on Youtube.

If that’s not enough I highly recommend listening to episode 220 of The Oribital Podcast. It has an excellent interview with Ron Burkey that will have you enthralled (well, maybe, if you’re like me and find the archaeology of old software interesting!)

The episode show notes link to scans of the original source code and transcribed copies of the code on Github!

Find scans of the source code above on archive.org and the same code is on Github too!

Categories
WordPress

WP Super Cache 1.6.9: security update

WP Super Cache is a full page caching plugin for WordPress.

Version 1.6.9 has just been released and is a required upgrade for all users as it resolves a security issue in the debug log. The issue can only be exploited if debugging is enabled in the plugin which will not be the case for almost all users.

The debug log is usually only enabled temporarily if a site owner is debugging a caching problem and isn’t something that should be left on permanently as it will slow down a site.

If there is an existing debug log it will be deleted after updating the plugin.

This release also improves the debug log by hiding sensitive data such as the ABSPATH directory of the WordPress install and login cookies. Unfortunately in the past users have copied the log file data into forum posts. A warning message has been added asking the site owner not to publish the debug log.

Details of the security issue will be added to this post in time to allow sites to update their plugin.

Categories
C64

Scrollwars

Yes, yes, another C64 demo. This is Scrollwars, released in 2013. How, just how?

Categories
Games

Dune Legacy: a modern Dune II game

Dune II, a real-time strategy game released in 1992, was as you may guess based on Frank Herbert’s second book in the Dune series. I didn’t play it at the time as I still owned a C64 at the time but I did play it before the decade was out.

In the game the player must harvest spice, return it to a refinery to convert to credits which are then used to build more harvesters or military units. Your military units are used to defend your harvesters and buildings and also attack your opponents. You control one of three opposing houses with the ultimate aim of conquering the other two.

Dune Legacy is a modern Dune engine that will allow you to play the original game with modern controls and higher resolution graphics. As well as Dune Legacy there’s also Dune Dynasty based on OpenDUNE.

They all require the original game to run but if you search carefully you’ll be able to find it online.

I haven’t played much of the game yet but it plays much the same way I remember in the past. Go get it if you’re a fan of RTS games. When you’re finished with that have a look at OpenRA, an open source implementation of Command and Conquer: Red Alert.

Categories
C64

An Intro to 6502 Assembler

In the bad old days of the 80s and 90s computers weren’t as fast as they are now. You had to fill ’em up with leaded fuel and they were noisy and hot and you had to keep the windows open to let the fumes out.

Well, maybe not. They weren’t as fast as the handheld machines in our pockets now but I’ll bet that a larger percentage of users back then at least tried to code something. People had to because it wasn’t always easy to get games. You had to go down the shops and get out of the house to buy any new software! You had to open the manual to find out how to load anything!

So it was that I figured out that I’d rather be coding than playing games, and with the purchase of a book on assembly (that has sadly gone missing in the last year) I got busy and created a bunch of demos on the C64.

I wish I’d had this video to watch when I was starting out! If you’ve done any sort of assembly programming it won’t be anything new but it’s presented in an easy to understand manner and is worth watching if you’re at all curious about how computers work because a lot of the terminology is going to apply to other systems too.

I’m really looking forward to seeing the rest of this series. I want to get back to doing some assembly programming. There’s plenty of documentation out there but it’s a matter of finding the time and energy to do it.

Categories
Podcasts

If you love “13 Minutes to the Moon”

13 Minutes to the Moon is a BBC podcast telling the story of the first Moon landing and all that led up to it and it’s gripping listening featuring recordings from the time, great music and great story telling.

However, if you want to dig deeper into the Apollo missions I would recommend the Omega Tau podcast episodes about the Apollo missions. I already blogged about them but it’s worth repeating since there’s probably a whole new audience that will want to hear more!

Episode 83 is an interview with W. David Woods about his book How Apollo Flew to the Moon:

… where he describes in great length all the detail a geek wants to know about how the Apollo spacecraft and the flights to the Moon worked. In the episode, we basically go through an Apollo mission and discuss aspects such as the mission structure, the workshare between the crew and mission control, communication and telemetry, guidance and navigation, approach, landing and re-launch on the Moon as well as re-entry and landing on earth.

In episode 97 he returned to talk about exploring the Moon!

This is the long-awaited follow-up to the first Apollo episode, once again with W. David Woods, author of How Apollo Flew to the Moon. In this episode we cover that part that we omitted in the first episode: the time on the moon. We talk about life support, the various scientific instruments and experiments as well as the technology and use of the lunar rover (about which David is actually writing another book).

If you’re really interested in the Apollo Guidance Computer you’ll love episode 167.

This episode is a mix between computer architecture, programming and (historic) space flight. We cover the ins and outs of the Apollo Guidance Computer. Our guest is Frank O’Brien, who wrote an incredibly detailed book about this machine. In the episode we cover the hardware architecture, the instruction set, the various layers (native, executive and interpreter) as well as some mission programs.

Follow those interviews up with episode 218, A Life in Apollo where Markus interviews George Knudsen about the Saturn 5 launch vehicle and Apollo.

George Knudsen started working in 1958 on the Redstone missile, and moved on to working on the Atlas ICBM. Later he worked on the Saturn 5 launch vehicle, where he was responsible for the fuel tanks. He was on the launch team at Cape Canaveral for various Apollo missions. In this episode with talk with George about his work in this fascinating period of science and engineering history.

The Omega Tau podcast has been going for many years and they have episodes on all sorts of engineering and scientific topics. For other episodes related to Apollo have a look at this search on his blog listing many more episodes.

Categories
C64

Tunnel Vision by OMG

Tunnel Vision, C64 demo

So, apparently this is the first demo by this developer and it’s amazing. Hell of a fire effect.

I discovered this while testing the SD2IEC on my C64. Assembly64 has a “One File Top 200” directory that I was working on because the disk images have characters the filebrowser has trouble with. This small bit of bash shell script will sanitise it before viewing on a C64:

for i in *
do
  mv -v "$i" "echo $i|cut -c13-|tr '[:upper:]' '[:lower:]'|tr -cd ' a-z0-9'"
done

It changes the filenames to lowercase and then removes anything but a-z, 0-9 and space and also cuts out the first 13 characters . There are still a few shortened filenames but it looks much better now.

Edit on July 8th, 2019: The SD2IEC is slow when there are lots of files in a directory, plus the directory contained other directories so I decided to move everything into directories named after the first letter of each directory with this code:

for i in *
do
    new_dir=echo "$i"|cut -b 1
    mkdir -p ../1/$new_dir
    cp -v "$i"/* ../1/$new_dir/
done

Everything’s in sub directories of a new directory called “1”. There are multiple demos in each directory but not enough that it’s too slow. 🙂

Categories
C64

Sam’s Journey with two fire buttons

I figured out how to play Sam’s Journey on the Commodore 64 using two fire buttons! One as a normal fire button and another for jumping.

C64 joysticks only have one fire button so jumping up in platform games requires you press up on the joystick. Back in the day we knew no better and did our best using the directional movements. It’s not very precise as it’s easy to slip into left and right too. Pressing a second button to jump was a luxury NES owners had! C64GS owners had a joystick with 2 separate fire buttons but I think there was only ever one game that took advantage of that feature.

Unfortunately you’ll have to use the Vice C64 emulator, Virtual C64, or another C64 emulator that allows you to map keys to joystick actions.

First of all, open the joystick settings in Vice. Here’s the one from version 3.1.

Assign a keyset to joystick 2. I used the keys T, G, “,” and “.” and the right CTRL to fire. Sam’s Journey actually plays reasonably well using those keys if you don’t want to go any further.

However, if you want to use a controller you’ll need another program to map those keys to controller actions. On MacOS I found Enjoyable, a free application that allows you to map controller buttons and other inputs to keyboard keys or mouse movements.

I simply assigned left, right and down on the d-pad to the correct keys, and then two fire buttons to CTRL (fire) and T (up) respectively and it worked!

The game is definitely more enjoyable but it’s just as hard as before. I could have sworn I ran out of lives in the past to be thrown back to the start of the level. Now I kept getting put back at the last checkpoint, which is an improvement I have to admit as I died quite often. 🙂

Categories
C64

We Come in Peace Demo

This is just amazing. All done on a lowly C64 by Censor Design and Fairlight. Grab the demo from csdb. Unfortunately it doesn’t work in the SD2IEC because it has a fastloader. I should buy an Ultimate II+ or Ultimate 64 shouldn’t I?

Categories
C64

C64 Spotted in Cash Connectors

In Cash Connectors, North Main Street Cork. €119.99 for a C64, datasette and I think 4 games. No mention of whether it’s working or not or even if it comes with a power supply.

First time I’ve seen a C64 in a shop here in years. Last time might have been in Maddens on Princes Street some time in the early nineties.