A couple of friends at university in the nineties had to write a boot sector software. (They had to measure tracer density in water in a cavern that was dropped into water on the surface.) They only had some old PC (XT or 286) and no hard-drive, so the boot sector approach was an obvious choice (also more resilient in a cavern than a HDD). They gave the project to a developer company. After a month or so, they asked for some status. The company said that they are making good progress, they have already shrunk the software to some 520 kB or so. Then, they were told that there must have been some misunderstanding. The constraint was 512 bytes and no 512 kB. So, it came back to the university where they wrote it in 514 bytes in two days. Then spent another two weeks to remove further 2 bytes.
@@amineabdz Just as with hardware, languages are being abstracted farther and farther away from "the computer". This has loads of benefits. My issue is that people who can do low level programming (C and below) are disappearing because most well-paying jobs are for languages like for example Python, and new generations usually aim for the top 5 best paying languages. While for example starting with a sound C foundation, learning OO languages is not particularly difficult, someone who has only done high level programming will struggle to ever go the other way.
there's times where 1 does not equal 1. First experience with this made me very frustrated. I wrote a debug message after each line showing the value and the expected value and whether they match. So confused when it got to where it said "1,1,false" meaning 1 = 1 returns false aka 1 does not equal 1. So what i did was just take the value multiplied by 1 and all of a sudden it showed "1,1,true" My guess is somehow the value was converted to a string and multiplying it would either force it into a number or throw an error.
@@TheZoltan-42 "people who can do low level programming (C and below) are disappearing" laughs in printf. (but seriously though yeah i absolutely hate python for how slow and clunky it feels to use.
@KoivuTheHab I've never done a physical release of the game, but there are several solutions for transferring files from modern computers to the C64. Zoom Floppy lets you hook a 1541 drive up to a PC/Mac via USB, SD2IEC or uIEC lets you load files from SD cards on your C64, and if you want the best (and can afford it), there's the 1541 Ultimate.
The game actually has to fit into 510 bytes, because it contains a signature at the end to make the bios recognize the disk properly. Not that big of a difference but interesting to point out.
@saultube44 Yes, but you can re-use it as variable RAM once the BIOS has JMPed to your code. And also, there's a little descriptor struct at the beginning of a floppy boot sector, but I don't know if the BIOS actually checks it. If it does, then you've only got ~450 bytes. I've once written an "OS" in Assembly that fit in the bootsector. I wrote OS in quotes, because all it could do was echo, reboot and shutdown. I also added a help command, but there was not enough space for the help text (the final binary was exactly 512B), so it just printed "No one can help you..." :P
I guess there's 2 in the bios. One when no disk is inserted and two when the inserted disk's boot sector cannot be read. Anyway I thought the same, that all of the msgs are located in the bios.
Imagine someone *modded/hacked* a system disk message and put a message that says "No keyboard detected, press any key to continue", that will be a perfect prank on incoming April Fools.
Frenz Vargas and that wasnt even a prank back when we ad AT keyboards - the bios message literally said: “Keyboard not found or keyboard error. Press F1 to continue” i mean obviously this depends on the BIOS you had on your motherboard... but still... :)
I remember the magic of the early demo scene. Put a floppy into my Amiga, it reads for a second, and then some unbelievable high class graphics stuff and awesome music pops up. Good times.
"Today's fish is trout a la creme" - haha! ...almost spilled my tea. I used to have a PC (a very long time ago when they were only just able to play actual audio files for the first time) that started up with that snippet of audio. "I will!" was neatly followed by the windows 3.1 startup screen as I recall. (it also had a period of asking me if I wanted any toast, and another when it announced that it's name was Eddie and it was feeling just great, guys) oh yeah :o) happy days, thanks for the memory, David!
David, your guess is right regarding the pixels that are probably being used as variable space (5:47). According to Oscar Toledo's explanation in his book, he made this decision to take advantage of the BIOS video-mode setup routine clearing the entire screen memory; this way, his variables are automatically initialized to zero, saving the few bytes of code required to perform this necessary initialization - talk about extreme optimization!
@@jeremypeters-fransen1901 I'm not sure that really makes sense. There are multiple data registers in x86, so there's no reason you should need any code to switch to a data storage segment and back to the video memory or anything like that. I suppose it would save setting the extra segment register, saving a mov instruction. EDIT: actually thinking about it more, you could be right. Not in terms of switching segments, but in potentially saving on segment overrides in instructions. Though it might be doable using the string registers since they default to the es segment. My first guess was that it was a debug feature. Having variables in video ram so you could track them.
@@ashcrimp yes, there are at least four segment registers (CS, DS, ES, and SS). However, using a non-default segment register for the operation at hand costs an extra byte for the "segment override" instruction prefix. It's much cheaper to set DS and ES to the same value (along with SS and CS, if you can get away with it) and live with the fact you can only access 64KiB of memory.
@@techgeeknzl yep, you're right, I was wrong. I thought that di and si indexing defaulted to the es segment. But testing it on qemu it looks like that may only be the case for string instructions. The stack is another option because it definitely doesn't use the data segment for memory access, but some quick tests with my disassembler makes me doubt that'd be any more optimized unless maybe you're only holding a tiny amount of data in memory.
@@ashcrimp "I thought that di and si indexing defaulted to the es segment. But testing it on qemu it looks like that may only be the case for string instructions." ds:si/es:di for lods/stos
Efficiency in coding is still there and will always remain at some level. It’s just that there are many more use cases when there is no need to push devices to their limit. But there are still people fighting bits and cycles just so that higher level coder could afford using JavaScript to control a kettle.
@@lillyanneserrelio2187 I though drag and drop programming languages were mostly for learning (like Scratch), are you saying that Microsoft uses something like Scratch for development?
@@Hacks4AllVideos youtube round-down the numbers, so if you have 1,000,102 subscribers it will show as 1,000,000 (1 million) and if you have 999,928 subscribers it will show as 999,900 or 999K - i'm unsure how youtube actually round the numbers but they're definitely rounded down in a way to not over compensate for nothing.
David, Thank you for all of your videos about the 70s and 80s business and gaming computers. I was born in 1990 and missed all of the computers you review, restore, and demo on your channel. My memory starts at about the SNES and Windows 95 so its really interesting to hear about tech before my time. I'm sure future generations will appreciate your willingness to share your knowledge. Thanks so much and keep up the great work.
When I first discovered AVG antivirus (in the Windows XP days), the documentation had a section explaining boot sector viruses. As a young person just getting into computers in a meaningful way, documentation like this was fascinating (and informative). I miss software documentation that actually explains the concepts behind what it's doing and not just how to make the program work.
Compare the C64 manual (which teaches you about BASIC programming, programming the music and graphics chips using hardware registers) to the silly little leaflet you get with a modern laptop that tells you how to plug in the power and headphones...
@@aleksanderbudzynowski3625 That's the difference between documentation and references written by computer engineers than some Asian kid writing an instruction booklet in vague broken English with poorly drawn visual graphics...
@@CopperheadGarage But you have the amazing library called the Internet. When I was learning to program in the early 1980's it was a huge problem to find and own technical documentation beyond the simple Basic language of the computer. I learned to read English, German, Swedish, French, Dutch to get best tips to program MSX 8 bit computers.
@@foersom5928 school was was easier when you guys were in school teachers weren't just there for the money the usa school system is fucked the whole country is fucked right now
I love it! This brings back memories of a very simple Tron game I wrote in ASM back in the 90s. I used debug to write it to the boot sector of a 3.5" floppy disk and called it "TronOS".
"Toledo" actually wrote a book on how to write boot sector game. He also wrote some very tiny chess program and one might be a boot sector chess. Familia Toledo is their company in Mexico that build sell distribute and support their own kind of computer. A few links to Oscar Toledo Gutierrez book, books would be welcome. But any search engine will bring you that too. More investigation on this amazing man and family might make a story for another videos too...
Wow, Dave, your explanation of what a boot sector is, how it works, and what it's used for seems just as efficient as one of these bits of software that all fits onto one! Nicely done!
This kind of pursuit of efficiency really needs to become a thing again... Just because we've got all the memory in the world doesn't mean that programs should gobble it all up. Very impressive work by the developers that made the featured games!
@@PatRiot- Alley Cat, Castle Wolfenstein, and original version of King's Quest are some of my favorites. Booter games weren't uncommon back in the day, and there are plenty of classics released that way. Tapper, BC's Quest for Tires, Lode Runner, Ghostbusters, Zork, etc.
@@dosnostalgic Those self-booting games are not the same thing as referred to here; the games in this video fit entirely into just the boot sector which is very impressive. I do remember playing Alley Cat (in monochrome CGA) in the 80s!
@@fredjones100 Yes, that is impressive that they are 512 bytes, but is it not impressive when all these other games also loaded and occasionally saved data without having to rely on DOS or a standard file allocation? ;) The principle is the same, so they are very much the same kinds of games to me, just very very small.
I don't think it's possible. The DOOM IWAD is about 10MB in size. At least what you would need to look at is creating a custom IWAD and perhaps customising a DOS sourceport like DOSDoom to be able to launch from the new IWAD.
An IWAD file? When you are working within the confines of 512 bytes, you don’t have the luxury of creating the layer of abstraction required for organizing data into files.
happy one million. I've been watching your videos for 6 years. ever since "How much memory do you need? - Part 1" I've learned a lot about old gaming, old laptops, computer codes, game consoles. thanks David.
@0:17 Thank you. Now I know where these particular set of sounds came from. I've always heard them used in other media to depict people who play video games and always thought they were just random sounds that weren't tied to anything.
me too... and i was reminded of Druglord classicreload.com/druglord.html and i wondered how big might that have been .. in its most basic form. that game was so basic and yet it really made me take up reading and studying investing, equities.
Makes me remember when I was doing a project on the then new IBM PC back in late 1981 or early 1982. Things were new and undocumented and there were three OS's for it (CPM/86, UCSD P-System, and PCDOS) that were available but none had anything beyond simple terminal support and we needed to interact more intimately with the hardware to do everything that we wanted. We spent months going through the BIOS and probing with a logic analyzer to find what was where and how to make it do the things we wanted. At the time only the green Monochrome Display Adapter card and display were available and mass storage was limited to floppies. It turns out that that video hardware required a bit to be set on a port during boot to start the horizontal sync on the video card. Also, the floppy lead screw on the steppers did not have a stop at the end of the screw. I remember putting together a floppy with a short machine language program in the boot sector that would, in just a couple of seconds after starting the boot, turn the video sync off which literally caused the monitor to howl loudly and burn out with smoke coming out of the case while at the same time stepping the heads off the ends on the floppies (making very satisfying clunks inside the main box as the heads fell off) and finally loading up a really loud noise into the shift register feeding the speaker, setting it to free run, disabling interrupts, and halting the CPU. All you could do was turn the power off to stop it but it could not be started again. It was a hoot but we only booted on that disk once - it was a several hundred dollar repair bill to fix things - but kept a copy under glass in a box on the wall with the sign to break open in emergency. I think the whole program took up only two or three dozen bytes on the boot sector.
@Seremix: most of the COD update is troll faces and another such garbage which is just filling up space that way you will buy a new hard drive if you don't then cod is just going to DDOS your computer and maybe even your smartphone and your tablet and your refrigerator and basically anything that is connected to your Wi-Fi will be f*****because that's how they're going to make money.
@@damienhartley1832 Activision don't sell hard drives, so they have absolutely no interest in forcing you to by a new one. They don't make any money at all by doing that. The reason their files are so huge is simply because the available bandwidth and disk capacity is now so enormous that they don't _have_ to bother with optimisation. It would take weeks of paid employee time to actually optimise the code and graphics to decrease file sizes and from the business perspective that's an unnecessary waste of time and money.
@@mklzer0 Nah, I have too much of a conscience and too low of a pay grade to be any kind of major company executive. If I was in charge of anything at Activision they'd be DRM free for starters.
Liked and subscribed. I have great admiration for programmers back in the day. Pioneer 10 (launched in May 1972) had only 48k of memory and Voyager 2 (August 1977) had about 68k. My first computer - an MEK6800D2 came with a whopping 1k (expandable to 4k) in 1978.
You know what Pac stands for? PAC. Program and Control. He’s Program and Control Man. The whole thing’s a metaphor. All he can do is consume. He’s pursued by demons that are probably just in his own head. And even if he does manage to escape by slipping out one side of the maze, what happens? He comes right back in the other side. People think it’s a happy game. It’s not a happy game. It’s a fucking nightmare world. And the worst thing is? It’s real and we live in it.
*squee* a red dwarf reference cat: FISH computer: today's fish is trout a la creme, enjoy your meal cat: *stares at 5 or 6 containers previously ordered* i will
Oo, I once made a bootloader pong game that has a very basic, follow the ball ai to play against. I was very proud of that thing ^^ I did it in x86 assembly and man not hitting the 512 mark was hard, it's realistically 510 due to the boot signature as well
As always, very nice info. I have owned numerous floppy disk computers and, I have never thought that the boot error message came from the disk itself! Awesome!
Hey David. Just want to say awesome job on all the content. I watched one of your videos for the first time last month and I'm hooked . Keep up the great work.
I agree with you. I'm part of the "Free BSD" movement, advocating for the talented people working on FreeBSD to devote that talent to working on something either substantially different and useful or on a more widely adopted base. FREE BSD! FREE BSD! :) Does that make me a troll?
@@brent8783 TrueOS... I find it to be a perfectly usable alternative to Windows... The moment Steam is ported to FreeBSD I will never touch another MS product in my life!!! Apache Open Office, Steam, Kodi, etc... MS has lost...
@@timfalardeau9753 Why do you like FreeBSD more than Linux? I don't know much about this but I thought of it as a slightly worse version of Linux used by some companies like Apple because of the license.
Is incredible how assemby language can save so much space in programs. For instance one of my favorite games Carrier is a game with 130 Kb that is a lot but game is incredible for the time was programmed. Love your channel David!
@coolkid The end user simply isn't willing to pay for miracles, particularly at the salary of modern programmers. The end user isn't willing to pay for anything in most cases; you're probably reading this on a free web browser with free ad-supported e-mail.
I always set the hard disk as the primary boot device. I don‘t want the system to look for a bootable floppy disk, CD/DVD or a network boot option before starting the OS. That‘s a waste of time. And if I actually want to boot from another device... Most BIOSes have a Fast Boot Menu, at least from 2000 onwards.
I am truly amazed with the programming skills of whoever wrote these games. The smallest program I was ever able to write was a serial port file transfer program for MS-DOS that was 766 bytes in size. I can't imagine how they could fit all this in less than 512 bytes...
You pointing out the variables being stored in display memory reminded me of something that happened to me once.. Back in the PC-XT with monochrome adapter days.. A friend of mine and i were programming a television captioning program, and we were given a half-done project in ADA, which we didn't fully understand. We didn't understand how to properly pass and return variables between functions, and we had stumbled upon the fact that the monochrome video adapter had 2k (2048 bytes) of RAM, but the screen, being only 80x25 only used 2000 of those bytes for display, leaving a REAL 48 bytes of RAM unused.. We used these 48 bytes for storing and passing data between functions in our code. It worked great, UNTIL we had a big demo scheduled, and the boss decided to buy a spiffy new "Paper white VGA" literally on the way to the airport to take our system to demonstrate for a customer. He thought it would look more impressive on this new expensive monitor. We set up in the hotel room to install the new adapter, and found that the whole program failed to work on the VGA adapter.. It had been months since we did it, so it took us a while to remember that we had used those "spare bytes" but we finally did remember, and we re-installed the monochrome adapter, just to use it as RAM, and then the system worked great on the VGA adapter, and the demo went on the next day as planned! The 8 bit (and in this case, early 16 bit! days) were certainly fun for stuff like this!!!
The second game should be named floppy-bird, what a missed opportunity :D
That was too big for the available space.
@@TWX1138 or maybe because f-bird kinda sounds like f-word?
There's one that's called Floppy Bird as well. Available as both a booter and a proper DOS program.
@@memes_gbc674 Or flip-bird as in flip the bird.
@@kblake5466 I doubt that doug would care. He deleted the original game.
A couple of friends at university in the nineties had to write a boot sector software. (They had to measure tracer density in water in a cavern that was dropped into water on the surface.) They only had some old PC (XT or 286) and no hard-drive, so the boot sector approach was an obvious choice (also more resilient in a cavern than a HDD). They gave the project to a developer company. After a month or so, they asked for some status. The company said that they are making good progress, they have already shrunk the software to some 520 kB or so. Then, they were told that there must have been some misunderstanding. The constraint was 512 bytes and no 512 kB. So, it came back to the university where they wrote it in 514 bytes in two days. Then spent another two weeks to remove further 2 bytes.
Dang, 1 byte a week
Meanwhile i'm struggling to queue threads on Python.
@@amineabdz Just as with hardware, languages are being abstracted farther and farther away from "the computer". This has loads of benefits. My issue is that people who can do low level programming (C and below) are disappearing because most well-paying jobs are for languages like for example Python, and new generations usually aim for the top 5 best paying languages. While for example starting with a sound C foundation, learning OO languages is not particularly difficult, someone who has only done high level programming will struggle to ever go the other way.
there's times where 1 does not equal 1.
First experience with this made me very frustrated. I wrote a debug message after each line showing the value and the expected value and whether they match. So confused when it got to where it said "1,1,false" meaning 1 = 1 returns false aka 1 does not equal 1. So what i did was just take the value multiplied by 1 and all of a sudden it showed "1,1,true"
My guess is somehow the value was converted to a string and multiplying it would either force it into a number or throw an error.
@@TheZoltan-42 "people who can do low level programming (C and below) are disappearing" laughs in printf. (but seriously though yeah i absolutely hate python for how slow and clunky it feels to use.
Funny how Tetris is the game analogy for this because it’s also about fitting as much as possible into a confined space
@@DanLoudShirts lmao Tetris is the #1 best selling game, the #2nd is Minecraft
tristan 123455 actually, Minecraft is #1 and Tetris is #2 now
dylan10182000 aycktuallyyyy
mambo bruh
Meanwhile in Google: Hey boss we made an on-screen keyboard app and it is only 300MB
Google's full of spyware
@@xtcrider8270 Use Bing then. oh wait...
Hey! It has gif support! And voice detector. And dictionary. 🤣🤣🤣
Duckduckgo or startpage
Android is infamous for having large application sizes.
"With all those ghosts chasing him, I hope they're xanax"
best line of the year.
took my comment lol
Benadryl pills - the pills ARE the reason he sees ghosts
@@StasConstantine lmaoo few people will get that
@@atartup Which could apply to Brian Mangan's comment. xanax -- wtf??
remove the last x and you have a code lyoko reference
HAHHAHAH SO FUNNY BRO
The system disk message part blew my mind.
Me too, all these years and I've probably never registered a difference
Same, I had always assumed it was part of the BIOS and not the boot sector itself...
Yeah, it was a similar "wait what" as with Playstation 2 logo during game boot. The actual playstation 2 logo animation is stored on game disc
@@zanfr123 yeah i guess every time we format it sneaks in there ha
huh never thought i would have heard that from a computer
Thanks for mentioning my games Minima and Splatform! :)
I love your channel, will you cover these in it? BTW I read your comment with your voice in my head :)
@@hqqns Thanks, I should do that sometime. Gotta dig up the source code for them!
The fact that this has a heart is the first evidence I've ever seen of The 8-Bit Guy reading comments.
@KoivuTheHab It's a Commodore 64 game. If you search csdb.dk for "Minima Reloaded" you'll find a good crack of it from 2017 you can download.
@KoivuTheHab I've never done a physical release of the game, but there are several solutions for transferring files from modern computers to the C64. Zoom Floppy lets you hook a 1541 drive up to a PC/Mac via USB, SD2IEC or uIEC lets you load files from SD cards on your C64, and if you want the best (and can afford it), there's the 1541 Ultimate.
The game actually has to fit into 510 bytes, because it contains a signature at the end to make the bios recognize the disk properly.
Not that big of a difference but interesting to point out.
Neh 2 bytes can be a big difference when you've only got 510 to play with.
could those 2 bytes be used as some sort of random variables maybe?
@@MattiasRehn yah that's a valid code golfing strategy. also, treating code as data, data as code
@saultube44 Yes, but you can re-use it as variable RAM once the BIOS has JMPed to your code.
And also, there's a little descriptor struct at the beginning of a floppy boot sector, but I don't know if the BIOS actually checks it. If it does, then you've only got ~450 bytes.
I've once written an "OS" in Assembly that fit in the bootsector. I wrote OS in quotes, because all it could do was echo, reboot and shutdown. I also added a help command, but there was not enough space for the help text (the final binary was exactly 512B), so it just printed "No one can help you..." :P
@saultube44 Some BIOS designs added various checks that were only tested with Microsoft boot sectors.
"Boot Sector Games" sounds like it could be the name of an indie developer.
I may or may not stea.. i mean use your idea
Thank bro
Game dev branch of Normsl Boots
That track on the floppy disk would be a cool logo
Edit: can I be a part of your company? My state just issued a shelter in place order..
Cough lion studios cough
2019: Hey look we made this game only 99 GB in size, so you don't have to download too much.
fun fact: they dont care how big the game is
i think you mean 2029
@@ivyflow3r im downloading with 15Mbits a game that is 81GB
LOL
Modern warfare is 150 GB... My rtx 2080 and i7 sometimes struggle to run that absolute madness of a game
I always though “Invalid system disk” was part of the BIOS!!
same! I am shocked! and amused! and I find it cute in a way, all the workarounds involved in making stuff work... I dunno
I guess there's 2 in the bios. One when no disk is inserted and two when the inserted disk's boot sector cannot be read. Anyway I thought the same, that all of the msgs are located in the bios.
me too , but you got the similar massage with unformulated diskette, or no IBM compatible one ,how?
If I remember right (it's been years) the BIOS will output something like, "sector not found," if there's no usable information in the boot sector.
i learned this when backing up boot sectors with dd in case of lilo messing up, it is indeed an obscure piece of trivia
"With all those ghost chasing him I hope it's xanax."
Oh jeez I didn't expect that kinda joke.
Biggest oof 🤣
too real
8 bit guy poppin xans and coding
Boot sector pac man is suicidal 😰
It's fine, don't worry about it
Imagine someone *modded/hacked* a system disk message and put a message that says "No keyboard detected, press any key to continue", that will be a perfect prank on incoming April Fools.
Frenz Vargas and that wasnt even a prank back when we ad AT keyboards - the bios message literally said:
“Keyboard not found or keyboard error. Press F1 to continue”
i mean obviously this depends on the BIOS you had on your motherboard... but still... :)
@@mityaboy4639 Microsoft did the same, when Mouse on Windows did not worked, the Troubleshoot said click on Start...
@@Xonasa1 But Start menu can be operated by keyboard. May be they should say push "Windows" bottom on key board then use arrow keys.
@@Xonasa1 And who can forget the Windows can not find drivers for your modem. Would you like to connect to the internet to download them.
@@mityaboy4639 This lasted into at least the late 1990s... My Win98 Gateway box does this, and the BIOS is dated 8/1999!
"FISH!" - "Today's fish is trout a la creme. Enjoy your meal."
A reference to an early episode of Red Dwarf, love it!
I remember the magic of the early demo scene. Put a floppy into my Amiga, it reads for a second, and then some unbelievable high class graphics stuff and awesome music pops up. Good times.
7:07 Love the Red Dwarf reference
I looked in the comments to find this specifically
@@kinderbueno9018 me too
@@sircompo Me Three...
I've been fished to death! 🐟😭
You gotta love KAT.
"Today's fish is trout a la creme" - haha! ...almost spilled my tea. I used to have a PC (a very long time ago when they were only just able to play actual audio files for the first time) that started up with that snippet of audio. "I will!" was neatly followed by the windows 3.1 startup screen as I recall. (it also had a period of asking me if I wanted any toast, and another when it announced that it's name was Eddie and it was feeling just great, guys) oh yeah :o) happy days, thanks for the memory, David!
I recall the entire thing as being from Red Dwarf.
It totally was from the first season of Red Dwarf. What a wonderful and random reference.
David, your guess is right regarding the pixels that are probably being used as variable space (5:47). According to Oscar Toledo's explanation in his book, he made this decision to take advantage of the BIOS video-mode setup routine clearing the entire screen memory; this way, his variables are automatically initialized to zero, saving the few bytes of code required to perform this necessary initialization - talk about extreme optimization!
I figured for sure it was so that data only had to sent to one sector of the memory. Which would actually save even fewer bytes.
@@jeremypeters-fransen1901 I'm not sure that really makes sense. There are multiple data registers in x86, so there's no reason you should need any code to switch to a data storage segment and back to the video memory or anything like that.
I suppose it would save setting the extra segment register, saving a mov instruction.
EDIT: actually thinking about it more, you could be right. Not in terms of switching segments, but in potentially saving on segment overrides in instructions. Though it might be doable using the string registers since they default to the es segment.
My first guess was that it was a debug feature. Having variables in video ram so you could track them.
@@ashcrimp yes, there are at least four segment registers (CS, DS, ES, and SS). However, using a non-default segment register for the operation at hand costs an extra byte for the "segment override" instruction prefix. It's much cheaper to set DS and ES to the same value (along with SS and CS, if you can get away with it) and live with the fact you can only access 64KiB of memory.
@@techgeeknzl yep, you're right, I was wrong. I thought that di and si indexing defaulted to the es segment. But testing it on qemu it looks like that may only be the case for string instructions.
The stack is another option because it definitely doesn't use the data segment for memory access, but some quick tests with my disassembler makes me doubt that'd be any more optimized unless maybe you're only holding a tiny amount of data in memory.
@@ashcrimp "I thought that di and si indexing defaulted to the es segment. But testing it on qemu it looks like that may only be the case for string instructions." ds:si/es:di for lods/stos
Efficiency in coding: a lost art
Efficiency in coding is still there and will always remain at some level. It’s just that there are many more use cases when there is no need to push devices to their limit.
But there are still people fighting bits and cycles just so that higher level coder could afford using JavaScript to control a kettle.
@@ulysses4536 Windows coders need to watch this. Every Windows edition grew in size. I remember the entire Win3.1 OS took barely 40MB
@Too Wun If the Windows OS bloated growth is the fault of *drag & drop coders, they should be drawn & quartered* And/Or tarred & feathered 😆
@@lillyanneserrelio2187 I though drag and drop programming languages were mostly for learning (like Scratch), are you saying that Microsoft uses something like Scratch for development?
It's still there and called optimization
UA-camr: MattKC actually made a snake game that is small enough to fit on one single QR code label. It's quite impressive.
Year but this was 512 bytes. His was 2.9k
His was 1k ish
@@canaDavid1 Still, he programmed a .exe, not a bootloader.
@@computer_dude Tru, it does still make his accomplishment impressive because of that.
@@20blog28 bootloaders are harder, as you have to write all i/o routines yourself, where an exe can use syscalls.
Congrats on 1 million subs
Woah. Yeah!
I hope it's legit and not UA-cam rounding up the numbers , but congrats!!! Still a lot of people!! :)
@@Hacks4AllVideos youtube round-down the numbers, so if you have 1,000,102 subscribers it will show as 1,000,000 (1 million) and if you have 999,928 subscribers it will show as 999,900 or 999K - i'm unsure how youtube actually round the numbers but they're definitely rounded down in a way to not over compensate for nothing.
About time! Should’ve got this more than a year ago
Many fellow nerds exist on the internet, yay!
"you can change this message to anything."
I called the cops and reported you for sorcery.
"I'm Sorry Dave, I can't boot from that."
"Excuse me sir, what seems to be the problem?"
*"Harry Potter deleted my boot sector."*
“Tetros”
“Oh, you mean Tetris”
“Shhh, you wanna get sued, boy?”
USSR: We own it. Clearly.
Does anybody own tetris' rights btw?
@@tralphstreet Yeah, I think most of the rights now belong to a few of the original creators who emigrated to the west.
No, it's clearly TetrisOS. 😎
not to try and bring u down or anything but its TetrOS cause its in place of an os / bios
I did not expect that Red Dwarf reference in Basic.
ua-cam.com/video/dkjbMoj0JY4/v-deo.html
FISH!
@@khatharrmalkavian3306 Today's fish is trout a la creme.
Enjoy your meal
"I'm gonna eat you little fishies.... "
David, Thank you for all of your videos about the 70s and 80s business and gaming computers. I was born in 1990 and missed all of the computers you review, restore, and demo on your channel. My memory starts at about the SNES and Windows 95 so its really interesting to hear about tech before my time. I'm sure future generations will appreciate your willingness to share your knowledge. Thanks so much and keep up the great work.
This was a classic 8 bit guy episode! Loved it!!!!!!! Love this style, simple interesting topics!
When I first discovered AVG antivirus (in the Windows XP days), the documentation had a section explaining boot sector viruses. As a young person just getting into computers in a meaningful way, documentation like this was fascinating (and informative). I miss software documentation that actually explains the concepts behind what it's doing and not just how to make the program work.
The vic 20
Compare the C64 manual (which teaches you about BASIC programming, programming the music and graphics chips using hardware registers) to the silly little leaflet you get with a modern laptop that tells you how to plug in the power and headphones...
@@aleksanderbudzynowski3625 That's the difference between documentation and references written by computer engineers than some Asian kid writing an instruction booklet in vague broken English with poorly drawn visual graphics...
@@CopperheadGarage But you have the amazing library called the Internet. When I was learning to program in the early 1980's it was a huge problem to find and own technical documentation beyond the simple Basic language of the computer. I learned to read English, German, Swedish, French, Dutch to get best tips to program MSX 8 bit computers.
@@foersom5928 school was was easier when you guys were in school teachers weren't just there for the money the usa school system is fucked the whole country is fucked right now
That's so fun! I never even registered what a boot sector was before this video, so thanks for explaining it
Now after you have registered this data into your storage banks you can interface with humans on the subject
This channel never ceases to amaze me. That's why I love it. The8bitguy and techmoan, my top two faves.
I love it! This brings back memories of a very simple Tron game I wrote in ASM back in the 90s. I used debug to write it to the boot sector of a 3.5" floppy disk and called it "TronOS".
I would love to see more tech demos, they always fascinate me.
Check out pouet.net for really cool demos in different size categories all the way down to 64 bytes!
@@bradcavanagh3092 down to 32 bytes, I've got one on there.
@@Stonemonkie1 Mad props!
OMG, I love the Red Dwarf reference in your basic program!
"Toledo" actually wrote a book on how to write boot sector game.
He also wrote some very tiny chess program and one might be a boot sector chess.
Familia Toledo is their company in Mexico that build sell distribute and support their own kind of computer.
A few links to Oscar Toledo Gutierrez book, books would be welcome.
But any search engine will bring you that too.
More investigation on this amazing man and family might make a story for another videos too...
The fact that a boot sector actually isn't a boot position of the disk but a program is really a new knowledge for me.
Wow, Dave, your explanation of what a boot sector is, how it works, and what it's used for seems just as efficient as one of these bits of software that all fits onto one! Nicely done!
That's cool. The Packman and Space Invaders were really impressive.
This kind of pursuit of efficiency really needs to become a thing again... Just because we've got all the memory in the world doesn't mean that programs should gobble it all up. Very impressive work by the developers that made the featured games!
I believe Tetris is the most enjoyable game out of all boot sector games
Have you played Alley Cat?
DOS Nostalgia I have not- nor have I heard of it.
Feel free to name a few boot games worth playing
@@PatRiot- Alley Cat, Castle Wolfenstein, and original version of King's Quest are some of my favorites. Booter games weren't uncommon back in the day, and there are plenty of classics released that way. Tapper, BC's Quest for Tires, Lode Runner, Ghostbusters, Zork, etc.
@@dosnostalgic Those self-booting games are not the same thing as referred to here; the games in this video fit entirely into just the boot sector which is very impressive. I do remember playing Alley Cat (in monochrome CGA) in the 80s!
@@fredjones100 Yes, that is impressive that they are 512 bytes, but is it not impressive when all these other games also loaded and occasionally saved data without having to rely on DOS or a standard file allocation? ;)
The principle is the same, so they are very much the same kinds of games to me, just very very small.
When the programmers had more fun making them than playing them brought a tear to my eye. Miss those days.
3:45 "The viruses were just small programs living in the boot sector." Sounds like a start of a great story. So curious to hear what happens next.
They evolve by spreading from machine to machine.... lol
@@brentfisher902 No I was joking about them evolving as they spread and gaining sentience
They break out of the computer and mutate into COVID19
Yup go see @danooct1
Junkie.mbr has entered the chat
It's always impressive when you see a game that is really efficient with it's code. These are pretty cool.
Someday they'll fit Doom in there. You'll see...
Yeah some guy will get Doom running on a toothbrush or something like that
I don't think it's possible. The DOOM IWAD is about 10MB in size. At least what you would need to look at is creating a custom IWAD and perhaps customising a DOS sourceport like DOSDoom to be able to launch from the new IWAD.
An IWAD file? When you are working within the confines of 512 bytes, you don’t have the luxury of creating the layer of abstraction required for organizing data into files.
You could make a doom style game with a top down view.
Well it is on the Commodore VIC=20 from what I remember...... So who is up for making the Sinclair ZX81 1K version! :-D
WE NEED A 1 MILLION SUBS SPECIAL RIGHT NOW, David
Congratulations on reaching 1 million subscribers, David! 🎉🎈🎂🎁😲😃👍🏼
happy one million. I've been watching your videos for 6 years. ever since "How much memory do you need? - Part 1" I've learned a lot about old gaming, old laptops, computer codes, game consoles. thanks David.
3:38 Aye, you forgot a
there!
NEVER forget the n-word!
@@Tychosvideos
Oh, right. Goddamn carriage returns!
@Kernels 0x means hexadecimal
7:07 Love the Red Dwarf reference!
Like the myth goes, “who would ever need more than 512 bytes of RAM?” ;-)
Lol. Nice
What's that from?
Evonix Bill Gates - however it was „640k of memory ought to be enough for anyone“
Well y'kno, if you want a scoreboard for space invaders I guess.
Pawel Hener yes, it’s a play on the original
Just had to say I love this channel and look forward fo every video. Thanks for all the great content!
@0:17 Thank you. Now I know where these particular set of sounds came from. I've always heard them used in other media to depict people who play video games and always thought they were just random sounds that weren't tied to anything.
Me who cant even make snake: Wow so talented!
I saw the title and thought this was about "loading games" (or "load in games" for our UK friends).
Still, you learn something new every day.
me too... and i was reminded of Druglord classicreload.com/druglord.html and i wondered how big might that have been .. in its most basic form.
that game was so basic and yet it really made me take up reading and studying investing, equities.
Sean Taft And how Namco got a patent for “inventing” them in the mid 90s.
This is so so cool. Love this about the NES as well. Nothing like resourceful game design
Makes me remember when I was doing a project on the then new IBM PC back in late 1981 or early 1982. Things were new and undocumented and there were three OS's for it (CPM/86, UCSD P-System, and PCDOS) that were available but none had anything beyond simple terminal support and we needed to interact more intimately with the hardware to do everything that we wanted. We spent months going through the BIOS and probing with a logic analyzer to find what was where and how to make it do the things we wanted. At the time only the green Monochrome Display Adapter card and display were available and mass storage was limited to floppies. It turns out that that video hardware required a bit to be set on a port during boot to start the horizontal sync on the video card. Also, the floppy lead screw on the steppers did not have a stop at the end of the screw. I remember putting together a floppy with a short machine language program in the boot sector that would, in just a couple of seconds after starting the boot, turn the video sync off which literally caused the monitor to howl loudly and burn out with smoke coming out of the case while at the same time stepping the heads off the ends on the floppies (making very satisfying clunks inside the main box as the heads fell off) and finally loading up a really loud noise into the shift register feeding the speaker, setting it to free run, disabling interrupts, and halting the CPU. All you could do was turn the power off to stop it but it could not be started again. It was a hoot but we only booted on that disk once - it was a several hundred dollar repair bill to fix things - but kept a copy under glass in a box on the wall with the sign to break open in emergency. I think the whole program took up only two or three dozen bytes on the boot sector.
Man, not only you automatically made me come back to my childhood but you actually taught that boy something!
This man snuck a Red Dwarf joke in. This is the best thing I've seen all day.
Meanwhile in Activision: * updates in Call of Duty now costs 300gb of free disk space *
@Seremix: most of the COD update is troll faces and another such garbage which is just filling up space that way you will buy a new hard drive if you don't then cod is just going to DDOS your computer and maybe even your smartphone and your tablet and your refrigerator and basically anything that is connected to your Wi-Fi will be f*****because that's how they're going to make money.
@@damienhartley1832 Activision don't sell hard drives, so they have absolutely no interest in forcing you to by a new one. They don't make any money at all by doing that. The reason their files are so huge is simply because the available bandwidth and disk capacity is now so enormous that they don't _have_ to bother with optimisation. It would take weeks of paid employee time to actually optimise the code and graphics to decrease file sizes and from the business perspective that's an unnecessary waste of time and money.
As a pirate I can relate
@@Anonymous551656 found the Activision executive
@@mklzer0 Nah, I have too much of a conscience and too low of a pay grade to be any kind of major company executive.
If I was in charge of anything at Activision they'd be DRM free for starters.
Wow, I never new that boot error message actually came off the boot sector. So cool!
Congrats on 1 million subs ur vids are amazing and you deserve it keep up the good work!
Liked and subscribed. I have great admiration for programmers back in the day. Pioneer 10 (launched in May 1972) had only 48k of memory and Voyager 2 (August 1977) had about 68k. My first computer - an MEK6800D2 came with a whopping 1k (expandable to 4k) in 1978.
“with all those ghosts chasing him, I hope they're xanax" - I lol'd
Probably ecstasy if our poor friend is seeing ghosts
@@lemius6154 LSD is a hell of a drug ...
They are 1mg klonopin
You know what Pac stands for? PAC. Program and Control. He’s Program and Control Man. The whole thing’s a metaphor. All he can do is consume. He’s pursued by demons that are probably just in his own head. And even if he does manage to escape by slipping out one side of the maze, what happens? He comes right back in the other side. People think it’s a happy game. It’s not a happy game. It’s a fucking nightmare world. And the worst thing is? It’s real and we live in it.
@@LaikaLycanthrope not a drug it’s a sacrament
*squee* a red dwarf reference
cat: FISH
computer: today's fish is trout a la creme, enjoy your meal
cat: *stares at 5 or 6 containers previously ordered* i will
Smeghead.
Nice Red Dwarf reference.
“help! Food escape”
Congrats on a million subs! Your channel definitely deserves that Gold Play Button.
Congrats on 1 Million Subscribes Its a big milestone keep going on!
1k Chess on the Sinclair ZX81 was remarkable.
Oo, I once made a bootloader pong game that has a very basic, follow the ball ai to play against. I was very proud of that thing ^^
I did it in x86 assembly and man not hitting the 512 mark was hard, it's realistically 510 due to the boot signature as well
I've watched this channel for years to understand everything I did as a kid.
As always, very nice info. I have owned numerous floppy disk computers and, I have never thought that the boot error message came from the disk itself! Awesome!
I have never been to this channel but I like what I see. Very nice intro and informative content. You have yourself a new subscriber and an upvote!
"I've been fished to death!" "Look out....Food escape!"
"Today's fish is trout a la creme. Enjoy your meal!"
Awesome reference.
"Fish!"
Oh smeg
I'm gonna eat you little fishie...
What reference ?
@@yeal_takian the British comedy scifi show Red Dwarf
Had no idea boot sector games existed. This is one of coolest videos I have seen in awhile!
Hey David. Just want to say awesome job on all the content. I watched one of your videos for the first time last month and I'm hooked . Keep up the great work.
Now this takes "512 games in one" to a whole new level
One game in 512
I like the Red Dwarf's Cat reference in DOS Basic
Loving your work, always informative and entertaining.
Congratulations on 1,000,000 subscribers!!!🎊🎉🍾🎈
You thought I wouldn't notice that Red Dwarf reference? That scene is from Red Dwarf, Season 1, Episode 3: Balance of Power. I'm onto you........
A chef? A white-hatted Ponce?
"It outranks you smeg for brains"
"Dos, Windows, and Linux."
The FreeBSD crowd NEVER gets any love!
I agree with you. I'm part of the "Free BSD" movement, advocating for the talented people working on FreeBSD to devote that talent to working on something either substantially different and useful or on a more widely adopted base. FREE BSD! FREE BSD! :) Does that make me a troll?
What is Free BSD?
@@brent8783 TrueOS... I find it to be a perfectly usable alternative to Windows... The moment Steam is ported to FreeBSD I will never touch another MS product in my life!!! Apache Open Office, Steam, Kodi, etc... MS has lost...
@@quaternarytetrad4039 FreeBSD is what Linux is trying to be, only much better...
@@timfalardeau9753 Why do you like FreeBSD more than Linux? I don't know much about this but I thought of it as a slightly worse version of Linux used by some companies like Apple because of the license.
0:59 - When your eyes instantly explode.
That's really cool! I also remember a fad of WIndows games that ran within their own 16x16 taskbar icons.
Is incredible how assemby language can save so much space in programs.
For instance one of my favorite games Carrier is a game with 130 Kb that is a lot but game is incredible for the time was programmed.
Love your channel David!
Meanwhile, half the modern games have 30-70% of their code being just layers of resource consuming clutter ... *Cough cough* bethesda *cough*
@coolkid I read that in Jerry Seinfeld's voice!
@coolkid The end user simply isn't willing to pay for miracles, particularly at the salary of modern programmers. The end user isn't willing to pay for anything in most cases; you're probably reading this on a free web browser with free ad-supported e-mail.
@@straightpipediesel no, the end user doesn't have a choice. Neither do most of programmers.
*cough* fortnite is 70gb per update on pc *cough*
How else you would need to buy a new computer because the one you bought last month can't run games no more?
Like the Red Dwarf reference!
2:53 I wonder how many people can actually relate to that!
I always set the hard disk as the primary boot device. I don‘t want the system to look for a bootable floppy disk, CD/DVD or a network boot option before starting the OS. That‘s a waste of time.
And if I actually want to boot from another device... Most BIOSes have a Fast Boot Menu, at least from 2000 onwards.
@@lonewretch Haha...that's ridiculous. Tried everything
I've been watching your vids for a good few years. I've only just noticed the red dwarf reference!!
Love it
I am truly amazed with the programming skills of whoever wrote these games. The smallest program I was ever able to write was a serial port file transfer program for MS-DOS that was 766 bytes in size. I can't imagine how they could fit all this in less than 512 bytes...
watchin' it on my laptop running "damn small linux" os
Why damn small though, when there are simpler to use, still powerful distributions?
Back in 8bit days, I remember participating in challenges for 2 line basic programs. We managed to do a lot.
5:02 "all the aliens look the same."
nice one
1 Million!! Congrats! Been here since 570k
i love your videos. Brings me back to my childhood. :)
Did i spot a red dwarf reference in there .......... ( !!!!!!! )
Who cares
@@Iliek Yo mama
@@genderbender307 what you know about my momma?
FISH!
@@DannyBeans Today's fish is trout a la creme. Enjoy your meal.
Wow .. and here I was going on about the days when we could "do anything" with 8K.
"Pill-Man" appears to be "Pac-Man" without the Power Pellets.
I almost feel that's a metaphor of some kind…
Maybe "don't do steroids"
he's taking all those pills to drown out the thought that the things that give him meaning and allow him to win are nowhere to be found
Great video, keep them coming. The boot sector virus talk: Pure nostalgia
You pointing out the variables being stored in display memory reminded me of something that happened to me once.. Back in the PC-XT with monochrome adapter days.. A friend of mine and i were programming a television captioning program, and we were given a half-done project in ADA, which we didn't fully understand. We didn't understand how to properly pass and return variables between functions, and we had stumbled upon the fact that the monochrome video adapter had 2k (2048 bytes) of RAM, but the screen, being only 80x25 only used 2000 of those bytes for display, leaving a REAL 48 bytes of RAM unused.. We used these 48 bytes for storing and passing data between functions in our code. It worked great, UNTIL we had a big demo scheduled, and the boss decided to buy a spiffy new "Paper white VGA" literally on the way to the airport to take our system to demonstrate for a customer. He thought it would look more impressive on this new expensive monitor. We set up in the hotel room to install the new adapter, and found that the whole program failed to work on the VGA adapter.. It had been months since we did it, so it took us a while to remember that we had used those "spare bytes" but we finally did remember, and we re-installed the monochrome adapter, just to use it as RAM, and then the system worked great on the VGA adapter, and the demo went on the next day as planned! The 8 bit (and in this case, early 16 bit! days) were certainly fun for stuff like this!!!
"with so many ghosts chasing him, i hope they're Xanax" 😂
"With all those ghosts chasing him. Hope there xannax"😂