Hi Robin! Thanks for your interest in my little "Easter egg". I'm glad to see it's still getting noticed all these years, and I enjoyed your video exposé. :)

*at least microsoft back then wasn't begging to make microsoft account.*

Back in high school in 82 the gazette magazine had a cool word processor program that seeded the random number generator with a code word, and would encode your messages. You could save and send messages to a friend with the same computer with the seed word, and they could read it... I was amazed back in the day.

Using the pseudorandom number generator to hide a string in integers reminds me a bit of Tupper's self-referential formula (a formula that, when graphed, displays the formula itself).

I could tell that wasn't an Easter egg xD It made me think of a story of a kid who thought that he was unlocking secret hidden games by typing in "really long cheat codes" into his c64.

It's been decades since I used a Commodore but I learned way back then that the best way to generate a TRUE random number is to use RND(-TI) with TI being the always-changing time value.

I learned to code (basic) on that model of PET in junior high school. I'm pretty sure I remember learning that the RND function wasn't that random :-) Good times!

Fascinating. Slightly related story: In the April 1985 edition of an all formats computer magazine published here in Britain (can't recall the name), there was a type in program that purported to seed the RNG with values likely to produce "art" while PLOTting pixels at random co-ordinates. The screen would slowly fill with what initially looked like random dots but would slowly resolve into a message. The message? The month is a clue! It was "APRIL FOOLS!" A quick practical lesson on the vastness of the number space of even 2 colour low resolution microcomputer screens! The ASCII values where obfuscated in a similar way. Having an Acorn Electron at that time (the little brother of the BBC Micro) was a great challenge. Eking more from the limited RAM (32K but around 12K-22K depending on screen mode) was always desired. Similar to how Elite packed data for several galaxies of 256 star systems each into even the Electron's tiny memory.

It's not that the RND(0) generates bad numbers, it's that it always takes the seed value from the CIA timer (or system time clock). It's possible to ask for a RND(0) value twice in a row before the system clock has "ticked" (about 30 times per second). This means the seed value will be exactly the same in both cases. There's also a problem that RND(0) will skip numbers in a given sequence; INT(RND(0)*300), if looped will *always* skip something like every fifth number from 1 to 300 - the number or pattern of skip depends on the range multiplier. *500 skips every other number and *1024 skips five numbers in a row. I had figured out once why this happens but now I can't remember. A rounding error when converting the clock seems most likely. The Ideal way to use RND in C-64 BASIC is to: 10 X=RND(0) 15 X=RND(1)* what-ever Line ten seeds the RNG with the CIA timer which has an extremely low probability of ever being the same number twice from one session to the next and does not require the user to input a seed value. Line 15 uses the previously generated number to seed the next value and does not suffer from sequence skip. If this is used every time (or even just periodically) that a random number is needed, it also prevents sequence cycle repetition. A truly random number comes from reading or PEEKing (54299) with voice 3 of the SID chip producing a high frequency noise wave form (voice 3 does not need to be "turned on" or outputting to the speakers to read this random number, but the voice three parameters for wave form and frequency do have to be set) . The SID used a non-biased NPN (internal) transistor to produce a true analog random wave form - collector current noise - like static on a radio or T.V.. The number retrieved is limited to 255 but by adding or multiplying several PEEKS and a bit of creative math you can get what ever range you need.This is also the fastest and easiest way to generate random numbers in ML. Try this for proof: 10 ?"[shift home]" 20 POKE 1024 + INT(RND(0)*300),1: GOTO 20 (the effect is the same without INT()) This will fill the first 7 and a half screen lines with the letter 'A'. You will see the pattern of skips and it will change by changing the multiplier.*400, *500, *1000, etc (don't go over 1024 or you start overwriting the program and it will crash)

I’ve subscribed. I like that you went to the effort to reverse his program. Funny to think that a true random number generator would contain the works of Shakespeare given the right seed. And would also contain every possible program including the number generator itself. Super weird.

Random Number Generation & its quirks is always fascinating, love the last message!

You had me until you started changing the number to get the RULES output. Well played!

Thanks 8BS&T, I enjoy your videos tremendously. 👏🏻👍 I'll soon try reminiscing my old assembly skills too... 🤪

Easter eggs should be relatively simple to trigger, not with such an elaborate program -- the moment I saw the listing I knew it was a fake. It is comparable to searching the ROMs for certain bytes in an arbitrary string, and then writing a program to print the bytes at those addresses and saying it is a hidden message in the KERNAL. But it is a good joke the author pulled on so many people. :) It basically demonstrates that you can decode random bytes to anything you want with the right "decoder", and why trying to decrypt strong encryption without keys is futile.

Just want to say that I really enjoy your channel. I used to own a C64 and later a C128 in the 80's and early 90's, but then parted with them for later machines. I am now going retro and have ordered the parts to make a new old C64 by using an Ultimate64. I know it's not exactly the same as an original machine, but possibly has a little more future proofing. Anyway, after such a long time away from my C64 world I will be returning to it and rekindling some of that early excitement. Your videos are always interesting and very informative and encourage my yearning for these older but still interesting computers.

As soon as I heard "hidden in the random number generator" i already knew that rng manipulation was gonna happen next

Very cool! I love these EasterEggs. I was unaware of the C16 one, so thanks for sharing that!

Super cool video! Very informative and entertaining. Thank you.

Another very interesting video. your videos blow my mind very in depth. Keep them coming

Really a top 8-bit channel, if not "the". Great job! cheers, M

Thanks again for this. I finally applied the RND trick on my Radio Shack Color Computer and have ben having fun with that.

did you seriously get out a PET 2001 for the camera and go out of your way to *mime* the keypresses?! I am so impressed by your dedication to the art :)

Just like on the CoCo, a variant of "WAIT6502" is present in Applesoft for the Apple II (at least the 9-digit versions shipped on ROM for the II+ and later, and most likely for the LASER 128). The FAC-sized constants are present, but just encoded slightly differently to the CBM ones. It's slightly more work, but all one needs is to write a short machine language program to print the 10 bytes at $F094 (you have to exclusive-or with $87 then set the high bit of each byte).

The BBC Micro has the names of the developers at the end of its ROM. I discovered this by accident back in the 90's when I did an electronics YTS scheme. We were using EPROM programmers to read and write code and me and a mate decided to lift the ROM from the BBC and bung it in the reader to see what would happen. We noticed the names in its HIMEM portion. I dont know if this was accessible with a POKE or whatever BBC BASIC used but I remember we got a proper bo###cking for 'deliberate mis-use' of equipment lol, well, I was only 16 at the time ha ha

This is funny... I had a C128 when I was a kid. KZfaq videos are listened to mostly while I am driving to and from work.. (so they only get half listened to...) My mind was wondering and I was thinking that I don't remember rnd being really random.. Wait - did someone find random sequences for the text they wanted?... Wait - did someone do a prank? Then I listened more intently and found out I was right! Great job!

Fantastic. I shouldn’t have shared this with my Color Computer friends... I would have loved to have tried this trick ;)

Hi Robin, I finally subscribed to your channel as I'm adding Commodores to my collection. I saw your number of subscribers sitting at 49.9K and hoped y single subscription would push you to 50K...no such luck.

That was fun. It's been a long time since I wrote RND(-TI) in a program. In Pascal on my x86 dos box, that RND(-TI) invocation changed to Randomize() which did a timestamp based init as well.

Having programmed BASIC games in the mid 80s, I suspected foul play when I saw that "simple four line program". Easter eggs were nearly unheard of in the 80s due to memory constraints and I understand the fury of CBM when they found out that valuable ROM space had been wasted. Programmers today have no idea of the anguish experienced in trying to shave off a few bytes just to squeeze a game into the memory of these early micros.

Thank you for the videos abou C64 Easter Eggs, they're amazing! I really am not an expert: I was a little child when a Commodre 64 appeared at home, and we have been using it for ages, above all for videogames. Once I tried to copy some program lines, from amagazine or a manual, to create a sound, and you can imagine a little girl what could do (the best things had been: I discovered colors, shapes, how change fonts from big to small, how to draw with them). But once we recieved this weird "not an egg" message. Just once. I am Italian and that time we did not know anything about Easter Eggs. So, when we read this message, we translated it literally, and we were really perplexed. What was this egg about? The sentence was lacking of too many parts to translate it properly, so we thought we got a bad gate or almost broke something; we knew pretty well how C64 worked when it got crazy, with all those @s and #'s; this time it gave us a proper sentence, but we still found it weird. It should be "Sorry, there are not hidden surprises here; please, try elsewhere". I think we could get it only with this super-long sentence. You made me remind of this singular and unique episode. - I also want to thank you about the Easter Eggs on vinyl discs: I noticed there were these weird handcarvings on brand new records, and I was really puzzled. Now, finally, I got why. And I could recognise the digital sound of Commodore 64 programs, as, once (again, only one time) I tried to listen a C64 videogame cassette on a common cassette recorder. I could hear it again! Thank you :-)

It was definitely much easier to seed the Random Number Generator on the original classic TRS-80 Computers (Model 1 - 4), you could simply type the command, "RANDOM", and all the work was done for you It was a little bit more involved on the TRS-80 Color Computer, and was achieved using the inbuilt timer module, (which was a constantly changing value), and then seed the RAM against that, and, you could set this, in two very different ways The first was very similar to the Commodore command, as it required a negative number, and was X=RND(-TIMER) The second way, was by using a POKE, to seed the RND command against the Timer module, and was POKE 280, PEEK(275) By typing in PEEK(275) on it's own, you can see the current value of the Timer module, which is a constantly changing number, between 0 - 255, before it resets back to zero

WOW that's some interesting stuff!

MOVE your hand! Stop talking! Hey Robin! keep kicking ass!

My favorite easter egg is definitely 4:48 :-) Greetings, Doc64!

Nice one! I remember the 8-bit guy reporting about an easter egg in MS BASIC in the C64 ROM.

:D , nice video! I remember that in the past, I and my friends put an easter egg in a tachograph build here in Brasil. But no one finds this. The Tachograph is SV-2001, built in 2001 from Seva Engenharia. I Don't remember the right version that applies.

Wow. Funny how there is still interest in these old computers. I remember Rainbow magazine! Now I’m inspired to dig out my TRS-80 Color Computer! My daughter had been begging me to show her the old TRS-80 and the BASIC programs I wrote back in the day! Guess it’s time to pull it out and plug it in! 😉

I seem to recall an easter egg in the coco3 where if you held a certain key combo while pressing the reset it would display a picture of the Microsoft team.

Hi.... what connector you do have plugged to get the video signal out? (I see a kind of board in blue). Thanks

Do you know why the default colours in a C64 were blue on blue? From a readability standpoint it doesn’t seem optimal. Although it feels great to see the old C64 again.

Thanks for bringing back my childhood. My very first computer was the Commodore 16.

Compiling that with PetSpeed and then running in the VICE x64 emulator with Warp mode enabled will make your search algorithm run dramatically faster. (Thanks for a great video, as this brought back plenty of fond childhood memories for me.)

enjoyable as always! btw - Commodore 16?!?!??? I don't recall ever hearing of that before

Good job ! Very interesting ! Thank you. I'm long time Sinclair 128K user and yes, it remainds me of "pseudo randoming" RANDOMIZE USR 15616 - TR-DOS call :)

Reminds me of those "Bible Code" books whereby with enough brute force, you could find any hidden message you wanted to 'secretly hidden' in the old-testament.

I ran the Bill Gates one up on a new Retrogames C64 Maxi and it almost runs properly, you get a bunch of randomish characters and then GATES SUCKS or RULES, looks like the emulators implementation of the random number generator is different enough to mess with things, interesting though.

how did you find it ?

I must have picked the wrong day to quit sniffing glue.

How do they search for easter eggs?

I own a C128 and never knew about that sys-egg.

I wonder, maybe the "Not an egg" comment was supposed to follow "Bill Gates Sucks" ? Perhaps to say "Bills Gates Sucks - Not an egg" ?? An attempt to "get that dig in" just a bit more, without being TOO Graphic about it?

When you showed the easter egg program, I thought to myself, this is a monkeys and typewriter thing.

4:11 "(Credit for discovering this Easter egg is due to the late *F. Jacques Beurrechamp,* whose rough notes were _obtained_ from the archives of the Trammel Memorial Library in West Chester, PA and summarized by the present author.)" -Tristan Miller

What would happen if you put in the killer poke on the PET emulator on VICE?

Brought back memories of how unrandom the random number generator was. Games using random numbers were really frustrating.

Thank you for posting. The "funnest" days of ones' childhood were spent infornt of an MC-10.

Aww that CoCo! I used to have one that I picked up at a thrift store when I was a teenager. One day it disappeared and I asked my mom, and she tried to convince me that it never existed, lol. I would have went completely insane except luckily a friend was with me when I got the thing. My mom was great.

An excellent demo of how psudorandoms work. I've never seen that done before

It'd be fun to build a table of matches for a quick lookup of other phrases. Pretty clever trick.

You're C64-C looks to be in pristine condition! Retro brighted, maybe? Anyway, I miss my old C64-C and all my disks that were lost many years ago. *sigh*

as always great video

You always generate a string of the same length as the string you are searching for. Only then you compare them. But if any of the generated character is not what you want, all subsequent generating is just eating cpu time. I can't test that now, but I think optimizing that (and thus pruning the search space earlier) would bring a big improvement, especially for long words.

I had never even heard of Microsoft in the early 80s+, high school year. The VIC-20 and C-64 were great computers. I used to write machine code to go fast. It was so much faster, you have time before you get your driver's license.

"Bill Gates Sucks" LOL

I wonder if the reason why some random numbers are similar is because there was a trigonometric element to their generation. Imagine a sine wave and as it peaks and troughs the values are changing the least.

The RNG has changed over time; I immediately suspected it was not an egg and opened up VICE to test it on its PET 2001 mode with BASIC 1 and it does not work with those numbers at all. Now I'm wondering what range of machines have the same RNG... (Maybe even on non-Commodore machines, but I would need to set those up.) EDIT: it works on the VIC-20, Plus/4, and the C128 in 128 mode. It does not work on BASIC 4 on either the CBM-II or the CBM-II-5x0, but the output on both of these was the same as the one on the PET BASIC 1, so maybe there are only two RNGs on the Commodore machines? VICE doesn't have a C65 emulator, so I can't check there. I forget if the TI-99/4A has Microsoft BASIC or not (but trying to use MAME's TI-99/4A emulation frustrates me to no end). I don't know if the ZX Spectrum uses Microsoft BASIC or not. And for the heck of it, I tried it on MSX-BASIC 4.0 on an emulated Panasonic FS-A1ST (since that's the configuration I had set up in OpenMSX Catapult at the time). It also doesn't work there (and produces an entirely different output than any of the Commodore machines). (Catapult provides a GUI frontend that allows me to, among other things, paste large blocks of text into the emulator, so I didn't need to type everything out multiple times =P )

another fasinating video Robin :)

I remember reading that to seed the random number generator with an unique value every time, use -TI as the seed value.

On the CoCo we used a=rnd(-timer) to seed the random number generator.

on the commodore you can actually get it to print just about any message you like

My brain is cranking on ways to obfuscate this more. Having RND in there might be a trigger that something.. crafted? is happening... Replace that with a poke/peek/sys to call the RND function so it looks more complicated perhaps. ;D

Library of Babel before Library of Babel

How were you supposed to discover those involved eggs?

I had the TRS-80 and never even noticed it was a Microsoft thing....nor knew about that easter egg. I never seen that PET model, I ended up getting the CBM Pet

This is, quite frankly, astonishing.

RND(0) uses TI as the seed. [Early] Pseudo random number generators were sequence generating functions which took the last random number as the initial value for the function to create the next pseudo random number which was then plugged back in to get the next, and so on. Seeding via a negative number just set the last pseudo random number to that value. Seeding via zero sets the last pseudo random number to a value based on TI (if not just TI itself). In a quick loop TI will not change much and the result is that the seeds are very close in value. The RND function possibly gives little weight to the lower bits of the seed, resulting in the clumping effect if you see. Also, "fixing" the sequence produced to generate the first 21 letters of the alphabet into words probably messed up the "randomness" of the function meaning that close seed values result in clumping - converted to letters possibly gave double letters. RND(0) is best used when there is an external random event to seed the function, and then not used again until the next external random event to reseed the function. The easiest external random event is the user pressing a key (the Applesoft deliberately (rapidly) incremented its random number seed pair whenever the GET command was used to get a character from the user, thus randomly disturbing the random number sequence).

I have a 1984 Xerox 820-II that runs CP-M 2.0, and I'm curious now to know if there were any easter eggs hidden in their code.😉 I had a TRS-80 at one point, but never really did anything with it, as it was right around the time that MS-DOS and IBM-DOS (PC-DOS) were the latest thing and everyone was building on those. My first *'real'* computer back in 1988 was an 80286 IBM/AT clone with 640K memory, a 2MB expansion board, and a 10mb. MFM hard disc, running MS-DOS 3.3. There was a big war between IBM and Microsoft right around that time to one-up each other in the DOS development game, and with the inherent problems in IBM-DOS 4.01, M$ actually moved ahead a bit taking advantage of the new EMS standard for utilizing memory over 1 MB... 1988 was a very busy year for all PC and software developers, and you can chart the progress here: en.wikipedia.org/wiki/Timeline_of_DOS_operating_systems 😉

You have such pillowy bear paws. XD

"The PET Revealed" (second edition 1980) lists the ROM routines of the old (2000 series PETs) and new (3000 series PETs [with the proper keyboards and no internal cassette dtive). For the new ROM it lists: D745-D76D Microsoft joke The length of the perform WAIT code is given as the same for each (1B bytes); so either the jump is there or some pre-perform code does the jump. (Interesting change of terminology over about 40 years.)

I wonder if you can speed it up even further if you store each character of the string into an array of integers. Also I wonder if performance would change if you would remove the for-loop and just replace it with a goto-loop: start with 20 B=-1, then 100 A=RND(B) (B is already negative so no need to let BASIC negate the number), then do all the other stuff and at the end do 130 B=B-1:GOTO 100.

Actually that MS easter egg was a copyright trap. The fact that that command produces the output proves it's MS code, even though the poweron screen doesn't mention microsoft. The Xevious name trick is another such copyright trap, and caught many people with bootleg games back in the day. Even if the company name and copyright were modified, if you did the trick it printed DEAD COPY MAKING copy under NAMCO program (if it was the original rom it would print NAMCO ORIGINAL program by EVEZOO).

Nowadays, Microsoft's 'Easter Eggs' come in the form of forced mandatory System Updates that break your computer. _"What are they like, ay?"_

As I recall, the RNG seed for this algorithm was only 16 bits, right? So it can only produce 65536 different sequences. You are using base-22 digits to display a string. log(65536)/log(22) =~ 3.5, so you can find all 3 letter strings, most 4 letter strings, and then it tapers off.

10:50 Thanks for the tip on using cbmbasic. I did a quick comparison and found that it runs about 5000 times faster than a C64, or about 500 times faster than using Vice in Warp Mode... Vice: 10 t=ti 20 forx=1to1e5:next 30 printint((ti-t)/60)"seconds" ready. run 117 seconds cbmbasic: 10 T=TI 20 FORX=1TO1E9/2:NEXT 30 PRINTINT((TI-T)/60)"SECONDS" READY. RUN 114 SECONDS READY. ?1E9/2/1E5 5000

First :) Edit: What a strange and fun story! I guess it be possible to use the rnd as a lookup table of sorts, perhaps saving a few bytes, depending on how small the routine to fetch the numbers could be made. Probably useless but a fun thought.

Is there an Easter egg in the plus/4 or the Amiga?

The C64 RNG is just a linear feedback shift register, right? So then you just need to feed it a seed that, when shifted, results in the desired byte sequence.

I can't find the "SUBSC RIBE" button so I clicked SUBSCRIBE instead. A cheeky and well earned sub indeed. Please can you do more assembly language? I would love to see how to implement randomness in 6502.

brilliant!

The first thing that came to my mind when starting the video was "what idiot back then would waste precious bytes for an easter egg message?" Apparently, I'm with Commodore on this one.

So,like at 14:00,the values for "A" are just numbers leading to a word stored in memory,and if you knew a particular words value,you can just create any 3-word phrase?

While typing in the program on an emulator for the first time in years, I found it interesting that I was instinctively using the keyboard shortcuts while typing in the program (? instead of PRINT, g,o, shifted-S for GOSUB, etc.) after all these years! Almost like riding a bike - you never truly forget!

WAIT 6502 right? It's because Commodore got a an absolute STEAL on prices for Microsoft BASIC at the time - One time payment and they got to use it for years. It's also why Commodore BASIC sucked for a very long time.

Random access text editing functions from within the screen buffering? That IS the shit.

Uhh, how it could be written by the computer - you need my picture ☺️

Wouldn't B% be faster than B in the for loop as well?

Excellent

You had me at 'CLICK SUBSC RIBE'

it's Halloween non the April's Fool day

I'm a simple man. I see BASIC CODE & I click.