555K subs 1111 video

I worked in the IC department at Texas Instruments that developed the TMS1000 from 1980-1983. This was one of TI's best selling devices and we were always in the process of designing new versions. It was an amazing design in regard to getting the most with the fewest transistors. One unique thing about the TMS1000 processor was the program counter. Rather than having a normal up counter, they used a pseudo random number generator which can be made with a simple shift register and a single exclusive OR gate. By tapping two points of the shift register into the inputs of the exclusive OR gate and feeding that back into the first shift latch the circuit would generate a repeating sequence of what appeared as random numbers. This circuit was extremely simple and required far fewer transistors than a standard counter, but it resulted in instructions being what appeared as random locations in memory. A normal counter will count in order from 0 to 2 raised to the power equal to the number of registers in the counter. A pseudo-random number generator will pass through all the numbers between 1 and 2 raised to the power equal to the number of latches in the shift register without repeating any number in what appears to be a random order until all numbers (except zero) have been passed. Because the Pseudo-random number can never output a zero it will always repeat one cycle sooner than a standard counter. This meant that each line of machine code could not be place in sequence in memory but scattered randomly throughout the memory making hand coding almost impossible. Because the pseudo-random sequence is the same each time (meaning it is not truly random) TI built into the macro assembler they provided with the product a converter that let the program code like a normal machine with conventional sequential addresses. Once the code was written, the assembler would lookup from a table and modified the written code locations to match actual pseudo-random locations.

I still have mine! This was probably the first electronic gadget I ever opened up to see how it worked. I remember being surprised that there was just a single chip in there, and I could not figure out how they could have fit all those games in that tiny, plastic block.

I really wanted a Merlin when I was a kid. But alas it was not to be.

I love when you put out videos that have some research put into them and extra text added in editing as you find out more information. I remember having trouble with those buttons when I was little.

I received one of those around 81-83 from Santa. I enjoyed it for a few years before it succumbed to leaky batteries and finally, The Screwdriver.

Begged for one for Christmas, and still have it. Not sure my parents would be pleased that it taught me blackjack.

Small speakers are only possible because of rare-earth magnetics, and the Nd magnet was about a 1980 invention (that has quietly changed the world)

LOL, I was cleaning the basement for new construction and found this exact toy of mine in a box hidden away for decades.... IT STILL WORKS... now Dave does a blog on one. How awesome is that? Good thing they are not FLASH memory, or probably would not work.

These were a huge cash cow for TI who supplied both the microcontroller and the LEDs. Reportedly there were more LEDs used in the production of the Merlin than in every product orderrd by the US DoD during it's production run.

Holy crap this takes me back. I played the hell out my Merlin many many years ago. I just realized by how familiar this looks that I ripped my apart a few times as a kid.

My sister had one and i loved it! I was born in 1970 so i remember this well! We played the memory game the most.

Most early games went through batteries. Spent many an hour adding power supplies to handheld games. Most of the time it was soldering iron to make hole in battery cover, knotted wire strain, and Lincoln logs used for spacers with brass tacks to hold the wires. Fast and easy for a 14 year old...

I had one of those Merlin games. I believe the Intel 4004 went on the market in 1971 followed by the 8008 in 1973. One source I looked at said that the TMS1000 was developed in 1971 but was not commercially available until 1974. I designed my first project using a microcontroller, the Signetics 2650, in 1976. None of this really matters to your video, but "who's first" is always interesting. *NOTE:* Watching the rest of your video, I stand corrected. The 4004 did require quite a few support chips, including RAM & ROM. The TMS1000 was a complete single chip microcontroller. You make a good point about how this made very inexpensive electronic devices possible.

I was totally obsessed with Magic Square! That game has never been duplicated again to my knowledge. I would love to find another one. Great video!

Fun Fact - I had a Merlin as a kid. At some point I didn't have access to batteries so I used my dad's 120v 3-prong plug with bare ends to power it. Seemed logical at the time. Blue smoke was released and never worked again.

Holy moly I must have been a lucky kid having one, The program I loved was the music sequencer, you could even program the rests. Man your awesome for posting this.

Eek! I had one of those. I'm old. Thanks for reminding me.

I saved for 4 months to buy Merlin myself, The absolute first computer I owned! I still have "most of him somewhere" great memory!!!

Found one of these like a year ago while thrifting! Knew it was an early one, but didn't realize it used the processor it did! Neat!

I used to have one of those. It was a great toy for the 70's.

What a blast from the past! I had a Simon as a kid, and my sister had a Merlin. We both got a lot of fun out of them.

I got a Merlin for xmas in 1979 and I loved it so much!! a superb little machine!

THE MERLIN! I loved that thing when I was a kid.

The Merlin was the best toy I ever owned back then. I got one the Christmas of 1978, I was 9 years old. My dad always said take care of it, it wasn't cheap... too bad it didn't talk.

These being back so many happy childhood memories. I think it's time to go hunting for 3d models of the case. I've got to make some of these for my (college aged) kids! If someone hasn't made them already for arduino then I've just found my fall project!

Hi! I am from Brazil and I had my Merlin until today! They were produced in here under Parker Brother license by a Brazilian former giant toymaker named ESTRELA (STAR) in 1981. I've noticed the joke with Star Wars in 14:50 of the video... But, when I was run out of batteries (most of time, since this little guy was a battery eater and the Brazilian version doesn't had the AC power option) I used to play with it pretending it was the BATTLESTAR GALACTICA ! LOL! ! The shape resembles a lot the old ship! LOL !

I had a merlin as a kid! I loved playing Magic square, and being able to beat the game with just a glance at the pads was insanely satisfying for young me.

Still have mine, and it still works. Dug it out of a box a few years ago. By some miracle, I must have removed the batteries the last time I played with it - probably around 1985.

Sweet teardown!!! Hadn't seen one of these since i was a kid. Just bought one on ebay for $15 to show my young'ns.

Pretty cool video; it certainly brought many memories. When I was a kid, the Merlin only arrived much later in Brazil (1981) and at a very steep price. The other game (Simon) was sold in Brazil as "Genius" but arrived in the previous year. At the time my impression was the same as yours: the Genius (Simon) was somewhat boring while the Merlin was much more interesting.

Thanks Dave!..great bit of nostalgia..that thing is as old as me!...reminds me of the old '79 version of electronic battleship board game (that would make an interesting, nostaligic tear down!)

Wow nostalgia overload, merlin was my greatest 11yo Xmas desire. Seem to remember due to cost my other presents were a bit light on that Christmas hahaha.

I still have my one! Loved tic tac toe and the memory game. I need to play it again now! Memories.

Oh boy, the feels are strong with this one. I got this for christmas when it came out and thought it was super cool. If I recall though, all the Mattel games were coming out around that time as well (football especially) so I don't really remember feeling like it was that advanced. Parents weren't to fond of it...

i am amazed how new it looks ..how well you took care of it ... great stuff

I love these old electronic games! I've got a bunch in various stages of repair and restoration that I'm messing around with :)

Brilliant Review of a toy made in the early 80's. Reminds me of the good old days as a kid. I played with merlin in the bus on the way to school. Mostly i played "senso" and mastermind. Finally the keypad broke. It payed around 50 DM (25 Euros) for this.

Nice video! However a few changes: The first microcontroller was actually the 4-bit Texas Instruments TMS0100, with first use in 1971. TMS0100 was heavily used in calculators but also for a few other products. The same team then designed the TMS1000 family with enhanced features and more RAM/ROM. Also the Merlin designers could not have used an Intel development system as those were only useful for Intel micros. Instead they must have relied on the TI simulator, which ran on IBM 360 as I recall.

I had one of these when I was just a little fellow. I had forgotten what it was called - now I know! Thanks.

Had one of these they were great

I was born in 46. Never heard of it, I do remember the Simon Says however. I once made a tick tack toe machine. We called it noughts and crosses in the old dart. It was made with just switches and bulbs, none of your led rubbish:) This was about 1958.

My parents had one and I used to play with the thing when I was younger. Of course, by time I got ahold of it the instructions were long gone and I had no idea how it worked, I just pressed buttons and made it beep. I was 6 or 7 at the time, so this was mid-80s.

co-inventor, Bob Doyle built Merlin together with his wife Holly Thomis Doyle and her brother Wendl Thomis. Simon, meanwhile, was invented by video game pioneer Ralph Baer and toy designer Howard Morrison. The two games came out simultaneously and had similar price tags of $25, or about $90 in today’s dollars. Alongside the first-generation video game consoles from Magnavox and Atari, which had reached the market a few years earlier, they helped introduce millions of people to the idea that computers could be fun to use, and maybe even educational.

where are the JTAG pins ?

I remember when I had to repair my sister's Merlin I put in a 9 volt jack instead of having 6 of those AA batteries. Simon was a fun game, too.

Looking at the datasheet, the TMS1100 was really advanced at the time, and also working on a very large voltage range. Intel unhooked the grall though, with their 8048 range integrated in so many keyboard !

Great video! I was born in '72 so would have been about six or seven years old when these things got to the UK. I don't specifically remember it but damn, it seems incredibly familiar. I guess maybe a friend must have had one but the conscious memory of it has gone, leaving this feeling of familiarity. Very weird!

In 1979 I persuaded the games shop I was working at to open the basement so we could demonstrate the electronic games that were coming on to the market. Merlin was hugely popular but we got such a bad discount from the suppliers it was cheaper for us to get them from Argos.

I bought one for my sister's kid. it was an amazing toy for 1979.

holy shit that thumbnail brought back a flood of memories

Cool! Never saw one of those, I guess I heard the name, but my kids wanted the Simon, so that's what they got for Christmas back then, my daughter got the Simon, my son one that was a bit more complicated, as he was a wiz with math and was drooling over computers at Radio Shack a few years later. At long last we got a family Commodore that the kids let me use when I worked the night shift, and they were at school. Ah yes those were indeed the good old days.

I had a to 4004 in my electronics class to learn assy on. this takes me back.

Man, I remember inheriting a Merlin from my brother and carrying out a couple of repairs (at the age of about 10) which included replacing a couple of LEDs. I only had green ones spare... by the time the dim green light had passed through that red plastic filter there was barely anything to be seen at all 😄 Ah, the learning curve...

I still have my Merlin, and it still works!

And a friend of mine had the submarine game as well as Electronic Battleship The submarine game was quite educational. Around that time I also had a board game with a handheld electronic console where you had to find and chase a crook. That soon failed on me.

Love it! had one in 1980, and remember trying to see if I could nest loops or do recursion on it :) What can I say, I was home on break after taking a hardcore CS class...

Wow! I had a Merlin back in the day!

Wow! Memories! I had one of these. Had forgot all about it.

I probably spent a solid year playing on Simon as a kid, it seemed like magic at the time. Also made a great play phone. Thats the first one I've ever seen that didn't have the color rubbed off the buttons.

Still got mine from '83. It's so loud, I put a vol pot on the side so I can play at night in bed! (with the lights out, of course) LOL

I guess the reason the power switch isn't labeled might be the molding technology used. The bright red part of the body has a geometry that is constant along one axis. Even the grooves on the side are basically a 3D extrusion of a 2D shape. Labeling the power button would have required additional effort.

Diodies! Keep that word Dave! Please!!!!????

Merlin, Mattel Microvision with Breakout, and Milton. "You turned me on!" My favorite 3 electronic games of that era.

I saw the thumbnail and just had to say that I have one of these from when I was a kid (like 12 years ago) and the tic tac toe game was awesome

A lot of the time, I'd rather have self-tappers into plastic than a brass boss. The brass bosses either blow out the side of the plastic boss they're pressed into, or the sonic welded/heat welded ones will spin. I always end up epoxying them back in to place. In fact, I did it yesterday to an electronic cigarette.

Oh damn dude I had this as a kid. Wish I still had it. The Merlin!!!! The other unit I liked was the frequency noise toy that was blue with orange knobs. I use to annoy the crap out of my parents! lolol.

Yea, the Merlin... Still have one in it's original packaging:)

I had a Merlin also when i was about 13 or so, and I called the Diode the same as how you said it.

Great stuff! I remember playing with one around the time they came out, however my family wasn’t rich enough to own one, $25 in 1978 money was a fair amount, over $95 in 2017 money! They were fun, though I recall that I only was interested in two of the six games since they weren’t all quite as amusing.

Still have two of those from back in the days…

My first music sequencer! Which considering the RAM limit is even more impressive. Still got it!

Gosh I remember taking mine to bits as a kid and fixing it to my bike, had some of the led outputs extended on wires to various points on my bike, I thought I looked so cool! ha ha.

Wow, it's a genius construction and genius case design! I think i've seen this toy in that old kid/teen movie hit "Big" with Tom Hanks... maybe.

I have one of these! Still works good as new.

I remember the Merlin and Simon - Our family was too poor to afford either of them but my best friends had them, so I spent a lot of time at their place... 👍😊

My cousin had a Merlin it was totally BRILLIANT!

I owned one in junior high/intermediate school. My dad helped me add an earphone jack so I could play it after finishing tests in class I actually had two. First one was stolen when i inadvertently left it in my desk in class.

I had Code Name Sector and the Merlin. I remember taking it apart and I too was amazed on how they made the switches. I would do a show and tell on it to anybody who would listen. I used to do a show and tell on the hot glue gun which I think came out about the same time.

Modern computer keyboards use the same type of key switches as this does, just with a rubber dome on top of them

That brings back childhood memories...i got one around early 80s when i still was late single digit ;)

I still have my Merlin, still working :)

Devices like this are interesting from the point of view of how much program can be squeezed in to such a small space. BTW, Wikipedia states the 16C84 was the first EEPROM-based PIC but it also says "The 68HC05 family broke ground with the introduction of the EEPROM-based MC68HC805C4 and MC68HC805B6 variants in the late 1980s."

AWESOME.. It would be cool to have the original source for that somehow. I got both a merlin and a simon that year, when I was 10.. Very cool and played them a lot! Good to see the detail on what was inside!

PLA in a microcontroller. Way ahead of their time! Nice video.

Diodies :-) When I was a young kid one of the first electronic components I ever bought was a relais. I read about it many times but without anybody else understanding this stuff and without any English lessons yet (I'm Dutch and I might have been 11 or so at the time), I did not know how to pronounce that. So I asked the shop owner for a re-laaaaaisch. He did not understand what I meant at first. I was ashamed, but heh, that's how you learn things.

Never seen that stuff. Would have been cool if you played just one minute on this thing though. Since I'm a retro stuff collector, i'm gonna have to get one of these primitive handy videogame-cell phones ! 😅

Wow, thats a blast from the past. Mostly I programed the 6502..... a bit different deal...

The membrane keys were also a cost cutting measure even though they had the ironic benefit of seeming futuristic.

Man i loved playing that game when i was visiting my rich friend in the 80s

Bit before my time but I remember the Simon says. Thanks Dave

just had to say I like your videos and this one in particular because it is my grandsons birthday 11/11 i live in SC USA keep up the good work

still have mine. loved it.

Wow this brings back memories. And thanks for the history and development of the Merlin... I briefly had one of these, it was given to me broken. My electronic skills were just beginner level, but I managed to find and fix the problem. I was having a lot of fun playing the games, but I wished I hadn't gloated so much about fixing it because the person who gave it to me asked for it back because their kids loved it so much and he couldn't buy (or find) another one. I had a soft heart and of course gave it back, but it felt kind of empty without the toy. Could you elaborate what the games were on the device? I remember vaguely some kind of memory game (ironic LOL) and for sure "tic-tac-toe" (blinking LEDs versus solid LEDs) , but there were six?

I believe Milton Bradley’s Electronic Battleship (1977) was another game to use the TMS1000. Had the Merlin too as a kid - flashing LEDs and electronic noises, what was there not to like!

I haven’t seen Merlins since the 70s. Lots of head to head games then. I remember it eats lots of batteries.

The big speaker also provided a sort of incidental haptic feedback, if I recall.

I had one of those as a kid (might still be in a box in my parent's garage). I got bored with it pretty quickly though, although I do remember enjoying the Blackjack 13 game more than the others.

I loved that game!

Wish I still had my Merlin...I put LOTS of hours on that thing...and yea...I took it apart more than once.