Masters of Doom is a great book on the history of id software, which includes the origins of the development of smooth scrolling by Carmack and Romero, which was groundbreaking at the time on PC.
The underlying mechanics of Carmack's technique is very similar to the full screen smooth scrolling effect on C64 at any speed and distance. It is nowadays referred to as DMA delay.
ELIF: You trick the CPU to display screen data at a different starting point than as designed by the hardware. This is tricky and need to be executed cycle exact.
Here is the explanation in detail together with all major top notch effects. The article is a legend and kind of the bible of doing the most sophisticated effects on C64. Some effects have since then even more and better explained and exploited due to cross platform development possibilities and better tooling, but understanding all mechanics here is a necessity to play a role in the Champions League of C64 demos, besides and also being able to implement the techniques mentioned here:
https://www.zimmers.net/cbmpics/cbm/c64/vic-ii.txt
It should be noted that John Romero released his own book, Doom Guy, a few years ago which contradicts some of the accounts in Masters of Doom. MoD is probably the more thrilling read and I enjoyed both books, but some of the stories need to be taken with a grain of salt.
I also think Doom Guy is worth a read because it gives a lot more insight into what happened at Ion Storm and how the Daikatana project fell apart. And some important context about the infamous "John Romero's about to make you his bitch" ad (mainly that he really didn't want to publish it at all). But I digress.
Yeah that's confirmed in Masters of Doom as well - sounds like Romero was a bit hesitant about it but Mike Wilson, the marketing guy, pushed him into it.
Lovely book. Skimming through it. One thing that might help contextualize it is a brief discussion of the how contemporary hardware like the SNES rendered sprites so efficiently compared to the PC hardware at the time. It's not obvious to modern readers why a PC with significantly more powerful compute capabilities would struggle to keep up with significantly slower Nintendo hardware at the time for sprite rendering.
>It's not obvious to modern readers why a PC with significantly more powerful compute capabilities would struggle to keep up with significantly slower Nintendo hardware at the time for sprite rendering.
To put it briefly, 4th generation and earlier games consoles saved on expensive RAM by not having frame buffers [0]. The CPU wrote a description of how to construct the scene using tiles and sprites to a smaller video ram, then dedicated video hardware converted this to the video signal one line at a time. The whole frame gets rendered from scratch every video refresh, so there's no need for tricks like Commander Keen's adaptive tile refresh. Scrolling at 60 fps (or 50 fps for PAL hardware) is as cheap as changing a single value in video memory. It's like the famous "racing the beam" of the Atari 2600, except less flexible and done by dedicated hardware so you don't tie up the CPU.
On the PC, the CPU writes the actual graphics to a frame buffer, then the graphics card outputs the contents of the frame buffer as the video signal. The naive approach to scrolling requires rewriting the entire frame buffer, so tricks to avoid redundant writes are highly beneficial.
[0] Except for the Atari Lynx, which was a portable system with a screen resolution of only 160×102. I can't think of any other exceptions, but maybe there are more.
I get what you're saying, but the comparison to "racing the beam" is maybe a little misleading, because the point is that you aren't "racing" the beam. Rather, the system is operating in perfect lockstep with the beam. From the software perspective, you set the scene up and then sit back while it draws. And then in the abstract and from the hardware's perspective it's not even one line at a time, it's one dot at a time.
It appears the author is leveraging Fabien's branding by copying not only the style of post but more importantly the formatting and style of Fabien's books. Even structurally the book appears quite similar.
If you didn't double check the author while skimming this Keen book, you may well be mistaken that it was written by Fabien.
I took a quick skim of the content, it looks great - tempted to purchase a copy to support the author for their efforts (and have it sit on the bookshelf next to two other very similar looking books...) but need to sit on this for a while.
Maybe I'm overthinking this. Would like to hear Fabien's take on the situation.
"...I discovered Fabien Sanglard’s website and began reading his Game Engine Black Books on Wolfenstein 3D and Doom. Inspired by those works, I wondered whether I could do something similar for Commander Keen: open up the source code, explore the files, and piece together a picture of the overall architecture and the clever tricks used. The style, dimensions, and structure of this book are intentionally similar to Fabien’s Game Engine Black Books, as an homage to those masterpieces. To give it a personal twist, I inverted the title and cover to white."
I can understand the feeling of loyalty to a widely admired figure (and deservedly so!) but this isn't a great way to respond to someone else's work. Unless there's some evidence of ill intent, why not just classify it as an homage?
"Please don't post shallow dismissals, especially of other people's work. A good critical comment teaches us something."
"Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith."
Fabien's site is an invaluable resource, but I think I've read it all over the years and he one has post specifically on Commander Keen, and that's focused on just the adaptive tile refresh (https://fabiensanglard.net/ega/). This book is 211 pages on the entire game.
On the first page this author credits Fabian's excellent analysis of Doom and Wolfenstein as the inspiration to attempt the same for Commander Keen.
> "Fast forward to 2021, I discovered Fabien Sanglard’s website and began reading his Game
Engine Black Books on Wolfenstein 3D and Doom. Inspired by those works, I wondered
whether I could do something similar for Commander Keen: open up the source code, ex
plore the files, and piece together a picture of the overall architecture and the clever tricks
used. The style, dimensions, and structure of this book are intentionally similar to Fabien’s
Game Engine Black Books, as an homage to those masterpieces."
Just skimming so far, but this book looks like a valuable contribution to the genre of retro game code analysis. Obviously, it will build on the work of others who've done adjacent research. In a page 87 footnote the author refers readers to Fabien's site for detailed instructions on installing a DOSBox and Borland C++ dev environment.
From the preface:
> Fast forward to 2021, I discovered Fabien Sanglard’s website and began reading his Game Engine Black Books on Wolfenstein 3D and Doom. Inspired by those works, I wondered whether I could do something similar for Commander Keen: open up the source code, explore the files, and piece together a picture of the overall architecture and the clever tricks used. The style, dimensions, and structure of this book are intentionally similar to Fabien’s Game Engine Black Books, as an homage to those masterpieces. To give it a personal twist, I inverted the title and cover to white.
Yeesh, until I saw your comment I thought this was Fabien. I'm sure it's not intentional but this goes beyond "homage" and into "deceptive". The replies to this claiming to not see what the issue is are inexplicable to me.
The work on the book itself looks fantastic, so it's a shame about the site design.
First, shallow dismissals are against HN guidelines, for a good reason.
And I fail to make the connection. This content-heavy but minimal design is not unique.
Text inside a centered element, text-heavy but also packed with images, exists from the times of formatinng websites with `<table>` tags in DreamWeaver or Microsoft Frontpage 98.
If you're talking about the highly detailed article, can we not gatekeep this? I want more of that on the internet, not less.
Masters of Doom is a great book on the history of id software, which includes the origins of the development of smooth scrolling by Carmack and Romero, which was groundbreaking at the time on PC.
Fun fact for C64 guys:
The underlying mechanics of Carmack's technique is very similar to the full screen smooth scrolling effect on C64 at any speed and distance. It is nowadays referred to as DMA delay.
ELIF: You trick the CPU to display screen data at a different starting point than as designed by the hardware. This is tricky and need to be executed cycle exact.
Here is the explanation in detail together with all major top notch effects. The article is a legend and kind of the bible of doing the most sophisticated effects on C64. Some effects have since then even more and better explained and exploited due to cross platform development possibilities and better tooling, but understanding all mechanics here is a necessity to play a role in the Champions League of C64 demos, besides and also being able to implement the techniques mentioned here: https://www.zimmers.net/cbmpics/cbm/c64/vic-ii.txt
It should be noted that John Romero released his own book, Doom Guy, a few years ago which contradicts some of the accounts in Masters of Doom. MoD is probably the more thrilling read and I enjoyed both books, but some of the stories need to be taken with a grain of salt.
I also think Doom Guy is worth a read because it gives a lot more insight into what happened at Ion Storm and how the Daikatana project fell apart. And some important context about the infamous "John Romero's about to make you his bitch" ad (mainly that he really didn't want to publish it at all). But I digress.
Yeah that's confirmed in Masters of Doom as well - sounds like Romero was a bit hesitant about it but Mike Wilson, the marketing guy, pushed him into it.
Ah I couldn't remember if that was only confirmed in Doom Guy. Regardless, it's still worth a read.
If you want to play it you can do that here: https://www.playdosgames.com/play/commander-keen-4
Sorry for the "asking for more"-style comment, but it would be amazing if this came in epub and not just PDF.
Would love to hear about the other Apogee and Epic games, like Epic Pinball, Tyrain, Halloween Harry, Jill of the Jungle, Duke Nukem...
Lovely book. Skimming through it. One thing that might help contextualize it is a brief discussion of the how contemporary hardware like the SNES rendered sprites so efficiently compared to the PC hardware at the time. It's not obvious to modern readers why a PC with significantly more powerful compute capabilities would struggle to keep up with significantly slower Nintendo hardware at the time for sprite rendering.
>It's not obvious to modern readers why a PC with significantly more powerful compute capabilities would struggle to keep up with significantly slower Nintendo hardware at the time for sprite rendering.
To put it briefly, 4th generation and earlier games consoles saved on expensive RAM by not having frame buffers [0]. The CPU wrote a description of how to construct the scene using tiles and sprites to a smaller video ram, then dedicated video hardware converted this to the video signal one line at a time. The whole frame gets rendered from scratch every video refresh, so there's no need for tricks like Commander Keen's adaptive tile refresh. Scrolling at 60 fps (or 50 fps for PAL hardware) is as cheap as changing a single value in video memory. It's like the famous "racing the beam" of the Atari 2600, except less flexible and done by dedicated hardware so you don't tie up the CPU.
On the PC, the CPU writes the actual graphics to a frame buffer, then the graphics card outputs the contents of the frame buffer as the video signal. The naive approach to scrolling requires rewriting the entire frame buffer, so tricks to avoid redundant writes are highly beneficial.
[0] Except for the Atari Lynx, which was a portable system with a screen resolution of only 160×102. I can't think of any other exceptions, but maybe there are more.
I get what you're saying, but the comparison to "racing the beam" is maybe a little misleading, because the point is that you aren't "racing" the beam. Rather, the system is operating in perfect lockstep with the beam. From the software perspective, you set the scene up and then sit back while it draws. And then in the abstract and from the hardware's perspective it's not even one line at a time, it's one dot at a time.
Someone ping Fabien Sanglard! Looks so much like his site!
And his site looks like another thousand, as I'm sure he knows.
We consume his site for the content, not for the minimalistic design that exist since the inception of the universe.
It appears the author is leveraging Fabien's branding by copying not only the style of post but more importantly the formatting and style of Fabien's books. Even structurally the book appears quite similar.
If you didn't double check the author while skimming this Keen book, you may well be mistaken that it was written by Fabien.
I took a quick skim of the content, it looks great - tempted to purchase a copy to support the author for their efforts (and have it sit on the bookshelf next to two other very similar looking books...) but need to sit on this for a while.
Maybe I'm overthinking this. Would like to hear Fabien's take on the situation.
Author's note from the book:
"...I discovered Fabien Sanglard’s website and began reading his Game Engine Black Books on Wolfenstein 3D and Doom. Inspired by those works, I wondered whether I could do something similar for Commander Keen: open up the source code, explore the files, and piece together a picture of the overall architecture and the clever tricks used. The style, dimensions, and structure of this book are intentionally similar to Fabien’s Game Engine Black Books, as an homage to those masterpieces. To give it a personal twist, I inverted the title and cover to white."
> To give it a personal twist, I inverted the title and cover to white.
That is a great idea.
How do you feel about this book mirroring your prior art in both format and structure? Were you consulted beforehand ?
Great write up. Reminds me of Cosmodoc, which is similar source but analyzes Cosmo’s Cosmic Adventure instead of Commander Keen.
https://cosmodoc.org
Of related interest:
Reconstructed Commander Keen 1-3 Source Code
https://pckf.com/viewtopic.php?t=18248 (https://news.ycombinator.com/item?id=46321982)
Have LLMs made all arcana about games engineering meaningless?
Another game from the same era: https://cosmodoc.org/
this looks like a copy of fabien's site, plus the topic is very related and likely trampolining on his brand :/
I can understand the feeling of loyalty to a widely admired figure (and deservedly so!) but this isn't a great way to respond to someone else's work. Unless there's some evidence of ill intent, why not just classify it as an homage?
"Please don't post shallow dismissals, especially of other people's work. A good critical comment teaches us something."
"Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith."
https://news.ycombinator.com/newsguidelines.html
Fabien's site is an invaluable resource, but I think I've read it all over the years and he one has post specifically on Commander Keen, and that's focused on just the adaptive tile refresh (https://fabiensanglard.net/ega/). This book is 211 pages on the entire game.
On the first page this author credits Fabian's excellent analysis of Doom and Wolfenstein as the inspiration to attempt the same for Commander Keen.
> "Fast forward to 2021, I discovered Fabien Sanglard’s website and began reading his Game Engine Black Books on Wolfenstein 3D and Doom. Inspired by those works, I wondered whether I could do something similar for Commander Keen: open up the source code, ex plore the files, and piece together a picture of the overall architecture and the clever tricks used. The style, dimensions, and structure of this book are intentionally similar to Fabien’s Game Engine Black Books, as an homage to those masterpieces."
Just skimming so far, but this book looks like a valuable contribution to the genre of retro game code analysis. Obviously, it will build on the work of others who've done adjacent research. In a page 87 footnote the author refers readers to Fabien's site for detailed instructions on installing a DOSBox and Borland C++ dev environment.
57 lines of CSS and the only distinguishing characteristic, the use of Deja Vu Sans Mono, isn't present.
This is trampolining on his "brand" as much as my text editor is
From the preface: > Fast forward to 2021, I discovered Fabien Sanglard’s website and began reading his Game Engine Black Books on Wolfenstein 3D and Doom. Inspired by those works, I wondered whether I could do something similar for Commander Keen: open up the source code, explore the files, and piece together a picture of the overall architecture and the clever tricks used. The style, dimensions, and structure of this book are intentionally similar to Fabien’s Game Engine Black Books, as an homage to those masterpieces. To give it a personal twist, I inverted the title and cover to white.
Yeesh, until I saw your comment I thought this was Fabien. I'm sure it's not intentional but this goes beyond "homage" and into "deceptive". The replies to this claiming to not see what the issue is are inexplicable to me.
The work on the book itself looks fantastic, so it's a shame about the site design.
First, shallow dismissals are against HN guidelines, for a good reason.
And I fail to make the connection. This content-heavy but minimal design is not unique.
Text inside a centered element, text-heavy but also packed with images, exists from the times of formatinng websites with `<table>` tags in DreamWeaver or Microsoft Frontpage 98.
If you're talking about the highly detailed article, can we not gatekeep this? I want more of that on the internet, not less.