@markmoxon.bsky.social - Mark Moxon

01 May 2026 16:23 +0000

My favourite game: Elite (picture 1) My latest purchase: Twin joysticks (picture 2) My plan: Squish ’em together to see what happens (picture 3) This should be a fun project! Note: Picture 3 is a genuine in-game work-in-progress screenshot, but it’s VERY early days… #retrocomputing #BBCMicro

30 Apr 2026 11:24 +0000

As promised, I've created a flicker-free version of the Elite Demonstration Disc for the #BBCMicro. It contains both flicker-free ships and planets. Play in browser: bbc.xania.org?autoboot&dis... Download disc image: https://elite.bbcelite.com/hacks/flicker-free_elite_downloads.html More info: elite.bbcelite.com/demo/ Enjoy! https://elite.bbcelite.com/demo/

29 Apr 2026 17:41 +0000

How cool is this? It's the #BBCMicro Elite Demonstration Disc, converted to run on the #Atari 8-bit machines. https://youtu.be/WHVVO3sUvFw?si=FiOnM7T3Ur-ET4vU Great work from Atari guru Wrathchild, who inspired me to look at the demo code in the first place! More details on AtariAge: https://forums.atariage.com/topic/389923-elite-bbc-self-playing-rolling-demonstration-port/

28 Apr 2026 15:02 +0000

I've just published a deep dive into the Elite Demonstration Disc, Acornsoft's self-playing #BBCMicro Elite demo from 1984 This links to a second deep dive that analyses every code difference that makes the demo the demo I'll make it flicker-free next, because why not! 😀 #retrocomputing https://elite.bbcelite.com/deep_dives/the_elite_demonstration_disc.html

26 Apr 2026 18:47 +0000

We have a new addition to the 6502 Elite Source Code Family Tree! Turns out the Elite Demonstration Disc is a fork of the cassette version, but incorporates the docking computer routines from the disc version for the self-flying combat AI. Welcome to the tree, demo. 🫡 #bbcmicro #c64 #nes #apple2

24 Apr 2026 16:07 +0000

I've just released a web version of the documented source code for the Elite Demonstration Disc, the 1984 self-playing demo from Acornsoft. elite.bbcelite.com/demo It's got syntax colouring, hyperlinked labels, code maps, indexes, stats and more. Deep dive coming soon. #bbcmicro #retrocomputing https://elite.bbcelite.com/demo

23 Apr 2026 21:43 +0000

This game is absolutely amazing. Take the 8-bit classic Chuckie Egg and wrap it around a tower like Nebulus- and the result is Chuckulus. It's a bit of genius, beautifully coded by @snuggsy187.bsky.social Seriously, take a look. It’s that good. 🫡 #BBCMicro [contains quote post or other embedded content]

23 Apr 2026 20:49 +0000

I've finished adding comments to my #BBCMicro Elite Demonstration Disc disassembly: https://github.com/markmoxon/elite-demo-source-code-bbc-micro Turns out the AI code is essentially the docking computer routines, which might explain why the ship in the demo is so rubbish at hitting things. :-) Web version & deep dive coming soon.

21 Apr 2026 15:33 +0000

Here's a new repository for the Acornsoft Elite Demonstration Disc. I haven't documented all the changes yet, but I have marked them up. Search the main source file for "Mod:" to see what Bell and Braben changed to turn the #BBCMicro cassette version into the demo... https://github.com/markmoxon/elite-demo-source-code-bbc-micro

19 Apr 2026 16:34 +0000

I've started disassembling the #BBCMicro Elite Demonstration Disc. Acornsoft sent this out to shops in 1984. It flies itself and contains rudimentary pilot AI. Did anyone see this back in the day? It’s fun to watch! You can run it in your browser: bbc.xania.org?autoboot&dis... #retrocomputing

17 Apr 2026 18:31 +0000

This is pretty amazing. Draw accurate landscapes from The Sentinel on a pen plotter? And animate them? I'm definitely in! https://newsletter.revdancatt.com/p/085-the-sentinel-adventures-in-animation I do my projects for a lot of reasons, but seeing what people do with them? Yeah, that's a big one. 😀 #bbcmicro #c64 #retrocomputing

12 Apr 2026 16:11 +0000

It's finished! The Sentinel, Geoff Crammond's epic game, is now fully documented. * 41,902 lines of lovingly annotated source code * 51 deep dives (116,240 words) * Buildable repository * 100% handcrafted AI-free content * 7 months’ work thesentinel.bbcelite.com #retrocomputing #C64 #BBCMicro

11 Apr 2026 15:23 +0000

Time for my last batch of deep dives into The Sentinel, Geoff Crammond's epic #BBCMicro game. This one's a mixed bunch of miscellaneous topics, from anti-cracker code to hidden snippets of original source code. Short and sweet! thesentinel.bbcelite.com/deep_dives Enjoy… #retrocomputing #c64 https://thesentinel.bbcelite.com/deep_dives

10 Apr 2026 15:44 +0000

What links The Sentinel with "Every Breath You Take"? Why, it’s the minor added 9th chord, of course! And the fact that they’re both 1980s classics Find out more in batch #10 of my deep dives: thesentinel.bbcelite.com/deep_dives Batch #11 (last one!) soon Enjoy! #retrocomputing #c64 #bbcmicro

08 Apr 2026 17:43 +0000

Find out how the Sentinel thinks with my latest deep dives Batch #9 covers enemy tactics, and following the gaze vector to work out what the player and enemies can see in the 3D world thesentinel.bbcelite.com/deep_dives Batch #10 (sound & music) coming soon Enjoy! #retrocomputing #c64 #bbcmicro https://thesentinel.bbcelite.com/deep_dives

06 Apr 2026 20:38 +0000

I just wrote word number 100,000 of my deep dives into the epic game The Sentinel. I know quantity <> quality, but milestones are important in projects this long. I started this project in September! Seems like a lifetime ago. Here's my progress chart. Nearly there… #retrocomputing #c64 #bbcmicro

02 Apr 2026 16:18 +0000

New release: deep dives #37 to #40 for The Sentinel, Geoff Crammond's epic #BBCMicro game This batch (#8) is a small release, covering the title screens, energy icons and scanner thesentinel.bbcelite.com/deep_dives Batch #9 is still in the oven, coming soon Enjoy! #retrocomputing #c64 #8bit https://thesentinel.bbcelite.com/deep_dives

26 Mar 2026 16:57 +0000

I've just completed 70% of my planned 50+ deep dives into The Sentinel, Geoff Crammond's epic #BBCMicro game Batch #7 is now ready: 4 new articles about drawing the 3D landscape, ray-casting and quadrants thesentinel.bbcelite.com/deep_dives Batch #8 coming soon Enjoy! #retrocomputing #c64 #8bit https://thesentinel.bbcelite.com/deep_dives

24 Mar 2026 16:20 +0000

Left: The Sentinel and four sentries, from the landscape preview in the classic game. Astonishingly, these are not sprites. They are fully rendered 3D objects, using the same code as the game. Right: a robot, drawn by the same routine. Micro *and* macro excellence! #retrocomputing #c64 #bbcmicro

21 Mar 2026 21:30 +0000

This is my first time using a memory heatmap to analyse #BBCMicro code Here's The Sentinel calculating landscape visibility (b-em emulator) Look: ray-casting radar patterns matching the landscape layout, right there in memory! The algorithm revealed! I love this #retrocomputing meta-level stuff 🤯

20 Mar 2026 19:39 +0000

Documenting The Sentinel is really growing my collection of disassemblies at bbcelite.com Five projects: Elite, Aviator, Revs, Lander, The Sentinel 1,038,891 words of source code commentary 507,016 words of deep dives All Shakespeare's plays? 835,997 words #retrocomputing #bbcmicro #c64 #8bit https://bbcelite.com

18 Mar 2026 16:55 +0000

Time for some more deep dives into The Sentinel, Geoff Crammond's epic #BBCMicro game! Batch #6 is now ready: 3 new articles about screen buffers, panning, scrolling and dithering thesentinel.bbcelite.com/deep_dives Batch #7 (drawing the landscape) coming soon Enjoy! #retrocomputing #c64 #8bit https://thesentinel.bbcelite.com/deep_dives

13 Mar 2026 16:12 +0000

Brand new weekend reading: even more deep dives into The Sentinel, Geoff Crammond's #BBCMicro epic Batch #5 covers the unique equirectangular projection system, drawing filled polygons, the screen mode and more thesentinel.bbcelite.com/deep_dives Batch #6 soon… Enjoy! #retrocomputing #c64 #8bit https://thesentinel.bbcelite.com/deep_dives

11 Mar 2026 16:55 +0000

I'm (slowly!) releasing 50+ deep dives into The Sentinel, Geoff Crammond's epic #BBCMicro game Batch #4 is now ready: 5 new articles about 3D objects (defining, drawing, managing) thesentinel.bbcelite.com/deep_dives Batch #5 (drawing polygons) coming on Friday Enjoy! #retrocomputing #c64 #8bit https://thesentinel.bbcelite.com/deep_dives

05 Mar 2026 16:50 +0000

Just released: 6 brand new deep dives into The Sentinel on the #BBCMicro and #C64 This is where it gets interesting! Generating 10,000 3D landscapes; tile data and shapes; enemies and trees; secret codes thesentinel.bbcelite.com/deep_dives#latest Batch #4 coming soon Enjoy! #retrocomputing https://thesentinel.bbcelite.com/deep_dives#latest

27 Feb 2026 21:20 +0000

This is pretty cool. It's a visualisation of the internals of The Sentinel on the #BBCMicro. This is it generating the game landscape for the first level from 256 pseudo-random numbers. Next week I'll be releasing a deep dive into exactly how this works. #retrocomputing #retrogaming #c64 #8bit

25 Feb 2026 16:46 +0000

I'm (slowly!) releasing 50+ deep dives into The Sentinel, Geoff Crammond's epic #BBCMicro game Batch #2 is now ready: 7 new articles about maths, geometry, trigonometry… and Revs thesentinel.bbcelite.com/deep_dives Batch #3 (landscape) coming soon Enjoy! #retrocomputing #retrogaming #c64 #8bit https://thesentinel.bbcelite.com/deep_dives

19 Feb 2026 16:28 +0000

I'm releasing over 50 deep dives into The Sentinel, Geoff Crammond's epic #BBCMicro game. Batch #1 is now ready: 6 new articles about memory maps, program flow and interrupts, all at thesentinel.bbcelite.com/deep_dives Batch #2 (maths!) coming soon. Enjoy! #retrocomputing #retrogaming #c64 #8bit https://thesentinel.bbcelite.com/deep_dives

31 Jan 2026 15:56 +0000

I've started writing a series of deep dives into Geoff Crammond's epic #BBCMicro game The Sentinel. Here's the to-do list. I will post a link here whenever I add a new one to thesentinel.bbcelite.com It's going to take a while! But it should be worth it... #retrocomputing #retrogaming #c64 #8bit

13 Jan 2026 11:42 +0000

You didn't know you needed this in your life, but you do. Marine Beaufils is a French artist who creates beautiful embroideries of... The Sentinel (amongst others). It's inspired and quite beautiful. Enjoy! https://www.marine.st/en/pages/sentinel #bbcmicro #zxspectrum #c64 #retrogaming #retrocomputing