Mark Moxon
@markmoxon.bsky.social
Writer, walker, software archaeologist. Back in the day: Editor of Acorn User, Editor of h2g2.
I love analysing old code, and my aim is to create the best code disassemblies you have ever seen.
Purveyor of Elite/Lander/Revs hacks.
www.markmoxon.com
I love analysing old code, and my aim is to create the best code disassemblies you have ever seen.
Purveyor of Elite/Lander/Revs hacks.
www.markmoxon.com
Glad you like it - that full view is quite something!
January 12, 2026 at 12:01 PM
Glad you like it - that full view is quite something!
Oh yeah, I see what you mean. Interesting, I guess that must be a typo in the MAME comment, because the ARM5 definitely isn’t a thing.
It’s nothing to do with the subject of your blog post, though, so I’ll shut up and go back to reading the good stuff. 🫡
It’s nothing to do with the subject of your blog post, though, so I’ll shut up and go back to reading the good stuff. 🫡
January 11, 2026 at 9:25 PM
Oh yeah, I see what you mean. Interesting, I guess that must be a typo in the MAME comment, because the ARM5 definitely isn’t a thing.
It’s nothing to do with the subject of your blog post, though, so I’ll shut up and go back to reading the good stuff. 🫡
It’s nothing to do with the subject of your blog post, though, so I’ll shut up and go back to reading the good stuff. 🫡
Great article! You’re one of the few bloggers whose stuff I always read, no regrets.
One thing: “the DECO 156 was apparently a custom encrypted ARM5 CPU”.
I don’t think there’s such a thing as an ARM5? Could it be ARM3, ARM6 or possibly ARM7, given the timeline?
en.wikipedia.org/wiki/List_of...
One thing: “the DECO 156 was apparently a custom encrypted ARM5 CPU”.
I don’t think there’s such a thing as an ARM5? Could it be ARM3, ARM6 or possibly ARM7, given the timeline?
en.wikipedia.org/wiki/List_of...
List of ARM processors - Wikipedia
en.wikipedia.org
January 11, 2026 at 8:59 PM
Great article! You’re one of the few bloggers whose stuff I always read, no regrets.
One thing: “the DECO 156 was apparently a custom encrypted ARM5 CPU”.
I don’t think there’s such a thing as an ARM5? Could it be ARM3, ARM6 or possibly ARM7, given the timeline?
en.wikipedia.org/wiki/List_of...
One thing: “the DECO 156 was apparently a custom encrypted ARM5 CPU”.
I don’t think there’s such a thing as an ARM5? Could it be ARM3, ARM6 or possibly ARM7, given the timeline?
en.wikipedia.org/wiki/List_of...
Take away the slow panning and the tiny POV and it isn't really the same game. The faster versions are OK, as the strategy of the game is still great, but I do feel they miss out on the magic of the original.
Sometimes faster gameplay and bigger POVs aren’t better - they’re just different, I guess!
Sometimes faster gameplay and bigger POVs aren’t better - they’re just different, I guess!
January 11, 2026 at 8:42 PM
Take away the slow panning and the tiny POV and it isn't really the same game. The faster versions are OK, as the strategy of the game is still great, but I do feel they miss out on the magic of the original.
Sometimes faster gameplay and bigger POVs aren’t better - they’re just different, I guess!
Sometimes faster gameplay and bigger POVs aren’t better - they’re just different, I guess!
It would be a different game, I suspect! The genius of the original is in the claustophobia of the small POV and the feeling of being trapped.
You know those dreams where you're desperate to run away but your feet are stuck to the floor?
That's the original version of The Sentinel.
You know those dreams where you're desperate to run away but your feet are stuck to the floor?
That's the original version of The Sentinel.
January 11, 2026 at 8:42 PM
It would be a different game, I suspect! The genius of the original is in the claustophobia of the small POV and the feeling of being trapped.
You know those dreams where you're desperate to run away but your feet are stuck to the floor?
That's the original version of The Sentinel.
You know those dreams where you're desperate to run away but your feet are stuck to the floor?
That's the original version of The Sentinel.
And here’s the thread on Stardot about it. It’s been around for a while now!
stardot.org.uk/forums/viewt...
stardot.org.uk/forums/viewt...
Atomic Elite
Hi guys, I want to share information about my latest conversion project for the Acorn Atom: ........ Atomic Elite. The source files are taking from the
stardot.org.uk
January 11, 2026 at 7:22 PM
And here’s the thread on Stardot about it. It’s been around for a while now!
stardot.org.uk/forums/viewt...
stardot.org.uk/forums/viewt...
It’s already been done! Atomic Elite is a real thing. 😀
I don’t know a lot about the Atom so I’m not sure if it needs an upgraded machine, but it definitely exists.
github.com/oss003/Elite
I don’t know a lot about the Atom so I’m not sure if it needs an upgraded machine, but it definitely exists.
github.com/oss003/Elite
GitHub - oss003/Elite: An Acorn Electron conversion of Elite for the Acorn Atom
An Acorn Electron conversion of Elite for the Acorn Atom - oss003/Elite
github.com
January 11, 2026 at 7:20 PM
It’s already been done! Atomic Elite is a real thing. 😀
I don’t know a lot about the Atom so I’m not sure if it needs an upgraded machine, but it definitely exists.
github.com/oss003/Elite
I don’t know a lot about the Atom so I’m not sure if it needs an upgraded machine, but it definitely exists.
github.com/oss003/Elite
The modern remakes, though? I bet they could do it no problem!
January 11, 2026 at 6:23 PM
The modern remakes, though? I bet they could do it no problem!
Also, the game uses the equirectangular projection, and that won’t change, so all you’d get would be more of the existing view squished into each screen, rather than the perspective shift in Minecraft.
Not sure Quake Pro real is a concept within the equirectangular world, outside of zooming… 🤔
Not sure Quake Pro real is a concept within the equirectangular world, outside of zooming… 🤔
January 11, 2026 at 6:21 PM
Also, the game uses the equirectangular projection, and that won’t change, so all you’d get would be more of the existing view squished into each screen, rather than the perspective shift in Minecraft.
Not sure Quake Pro real is a concept within the equirectangular world, outside of zooming… 🤔
Not sure Quake Pro real is a concept within the equirectangular world, outside of zooming… 🤔
Ah, OK found it - in Minecraft, WTF!
Yes, I think it would be possible to squeeze more angles into a single screen view, but the Beeb just doesn’t have the resolution for this to look good, and it would require a fair amount of recoding.
So that’s probably a technical “yes”only!
Yes, I think it would be possible to squeeze more angles into a single screen view, but the Beeb just doesn’t have the resolution for this to look good, and it would require a fair amount of recoding.
So that’s probably a technical “yes”only!
January 11, 2026 at 6:16 PM
Ah, OK found it - in Minecraft, WTF!
Yes, I think it would be possible to squeeze more angles into a single screen view, but the Beeb just doesn’t have the resolution for this to look good, and it would require a fair amount of recoding.
So that’s probably a technical “yes”only!
Yes, I think it would be possible to squeeze more angles into a single screen view, but the Beeb just doesn’t have the resolution for this to look good, and it would require a fair amount of recoding.
So that’s probably a technical “yes”only!
What’s Quake Pro field of view?
January 11, 2026 at 5:56 PM
What’s Quake Pro field of view?
I might do a proper one-to-one at some point, but this took ages - loads of individual screenshots, each one cropped from the b2 export and then stitched together (the starting screen image in this thread is an example of a b2 export).
I wrote an ImageMagick script, but still, it took forever!
I wrote an ImageMagick script, but still, it took forever!
January 11, 2026 at 5:22 PM
I might do a proper one-to-one at some point, but this took ages - loads of individual screenshots, each one cropped from the b2 export and then stitched together (the starting screen image in this thread is an example of a b2 export).
I wrote an ImageMagick script, but still, it took forever!
I wrote an ImageMagick script, but still, it took forever!
Also, they don’t match mode 5 pixels anyway, as they are rectangular, so that’s another mismatch!
They’re just a bit of fun, not exact matches - I probably should have been explicit in saying this, but things always get missed out in these tiny messages!
They’re just a bit of fun, not exact matches - I probably should have been explicit in saying this, but things always get missed out in these tiny messages!
January 11, 2026 at 5:11 PM
Also, they don’t match mode 5 pixels anyway, as they are rectangular, so that’s another mismatch!
They’re just a bit of fun, not exact matches - I probably should have been explicit in saying this, but things always get missed out in these tiny messages!
They’re just a bit of fun, not exact matches - I probably should have been explicit in saying this, but things always get missed out in these tiny messages!
That’s because I exported these from the b2 emulator, which applies a horizontal correction that can’t be disabled (that’s the aliasing you’re seeing).
I didn’t say these were one-to-one pixel screenshots directly from the BBC screen, as they aren’t. They just show the full landscape in one go.
I didn’t say these were one-to-one pixel screenshots directly from the BBC screen, as they aren’t. They just show the full landscape in one go.
January 11, 2026 at 5:11 PM
That’s because I exported these from the b2 emulator, which applies a horizontal correction that can’t be disabled (that’s the aliasing you’re seeing).
I didn’t say these were one-to-one pixel screenshots directly from the BBC screen, as they aren’t. They just show the full landscape in one go.
I didn’t say these were one-to-one pixel screenshots directly from the BBC screen, as they aren’t. They just show the full landscape in one go.
All three of which were born on the BBC Micro. 😀
You have good taste!
You have good taste!
January 10, 2026 at 5:59 PM
All three of which were born on the BBC Micro. 😀
You have good taste!
You have good taste!
Well put! This game is a work of art and so atmospheric.
Scary too. And eerie at times. It’s so clever…
Scary too. And eerie at times. It’s so clever…
January 10, 2026 at 5:42 PM
Well put! This game is a work of art and so atmospheric.
Scary too. And eerie at times. It’s so clever…
Scary too. And eerie at times. It’s so clever…
And here's the game's opening screen, for reference.
January 10, 2026 at 5:20 PM
And here's the game's opening screen, for reference.
To see the landscape images in their full glory (i.e. without social media trying to be helpful), here are links to the full images:
Plain landscape: thesentinel.bbcelite.com/images/panor...
Landscape with grid points: thesentinel.bbcelite.com/images/panor...
Zoom in to see the detail...
Plain landscape: thesentinel.bbcelite.com/images/panor...
Landscape with grid points: thesentinel.bbcelite.com/images/panor...
Zoom in to see the detail...
January 10, 2026 at 5:12 PM
To see the landscape images in their full glory (i.e. without social media trying to be helpful), here are links to the full images:
Plain landscape: thesentinel.bbcelite.com/images/panor...
Landscape with grid points: thesentinel.bbcelite.com/images/panor...
Zoom in to see the detail...
Plain landscape: thesentinel.bbcelite.com/images/panor...
Landscape with grid points: thesentinel.bbcelite.com/images/panor...
Zoom in to see the detail...
For those who don't know, The Sentinel is a classic game from 1986, written by Geoff Crammond and published by Firebird.
It was originally released on the BBC Micro, and was converted to lots of other home computers, including the Commodore 64, ZX Spectrum.
See thesentinel.bbcelite.com for more.
It was originally released on the BBC Micro, and was converted to lots of other home computers, including the Commodore 64, ZX Spectrum.
See thesentinel.bbcelite.com for more.
Fully documented source code for The Sentinel on the BBC Micro
Fully documented source code disassembly for The Sentinel on the BBC Micro, with lots of deep dive articles explaining how every aspect of the game works.
thesentinel.bbcelite.com
January 10, 2026 at 5:10 PM
For those who don't know, The Sentinel is a classic game from 1986, written by Geoff Crammond and published by Firebird.
It was originally released on the BBC Micro, and was converted to lots of other home computers, including the Commodore 64, ZX Spectrum.
See thesentinel.bbcelite.com for more.
It was originally released on the BBC Micro, and was converted to lots of other home computers, including the Commodore 64, ZX Spectrum.
See thesentinel.bbcelite.com for more.
So the game screen shows shows 1/9.7 of the full height and 1/12.8 of the full width of the landscape.
The weird figures are because the screen is a different shape to the full view.
Also visible is the point carée equirectangular projection used in the game. This is taken straight from Revs.
The weird figures are because the screen is a different shape to the full view.
Also visible is the point carée equirectangular projection used in the game. This is taken straight from Revs.
January 10, 2026 at 5:10 PM
So the game screen shows shows 1/9.7 of the full height and 1/12.8 of the full width of the landscape.
The weird figures are because the screen is a different shape to the full view.
Also visible is the point carée equirectangular projection used in the game. This is taken straight from Revs.
The weird figures are because the screen is a different shape to the full view.
Also visible is the point carée equirectangular projection used in the game. This is taken straight from Revs.
Yes, you can look up a surprisingly long way, though in the early levels things are relatively flat so all you see is screen after screen of sky. When you look down you can see your own tile, so that’s a bit easier to fathom.
I’ve been making panorama shots, so I might make a post on this topic!
I’ve been making panorama shots, so I might make a post on this topic!
January 10, 2026 at 11:25 AM
Yes, you can look up a surprisingly long way, though in the early levels things are relatively flat so all you see is screen after screen of sky. When you look down you can see your own tile, so that’s a bit easier to fathom.
I’ve been making panorama shots, so I might make a post on this topic!
I’ve been making panorama shots, so I might make a post on this topic!
In mode 5 pixels, the full landscape view is 1856 pixels high and 2048 pixels wide.
The game screen shows shows 192 by 160 pixels, so that's 1/9.7 of the full height and 1/12.8 of the full width.
The weird figures are because the screen is a different shape to the full view.
There you go!
(2/2)
The game screen shows shows 192 by 160 pixels, so that's 1/9.7 of the full height and 1/12.8 of the full width.
The weird figures are because the screen is a different shape to the full view.
There you go!
(2/2)
January 9, 2026 at 11:19 PM
In mode 5 pixels, the full landscape view is 1856 pixels high and 2048 pixels wide.
The game screen shows shows 192 by 160 pixels, so that's 1/9.7 of the full height and 1/12.8 of the full width.
The weird figures are because the screen is a different shape to the full view.
There you go!
(2/2)
The game screen shows shows 192 by 160 pixels, so that's 1/9.7 of the full height and 1/12.8 of the full width.
The weird figures are because the screen is a different shape to the full view.
There you go!
(2/2)