EEVblog #1308 - 1970's Intel MCS-85 8085 Design Kit!

hi I'm super excited about this one check this out you might have seen this before in the background on my mailbag video shelf Intel delivers tada what is it it is the intel mcs 85 system design kit it dates from 1976 yes that's only four years after man last set foot on the moon unbelievable now this is what you got if you wanted to play around with a processor back in the 1970s cuz it was a lot of work just to blink a LED back then not as easy as it was these days let alone do anything more complicated so a development kit or system design kit as they called it was a relatively simple way just to get up and running with in this case Intel's latest micro processors cuz otherwise it would have been like a real chore this allows you to play around with the processor and write programs for it and test them out and actually I connect up to hardware and things like that as we'll see so we're very nice bit of kit and yes it is actually a kit it's look we got all the chips I love the block diagram the system bus is beautiful and all the miscellaneous through whole numbers surface mount rubbish parts we even get the IC sockets Wow so these sorts of kids were pretty much the only game in town back then and because Intel wanted to encourage people to buy their chips cuz that's what that was their business they they sold chips and that was basically it they didn't really want to make money from these development kits so they sold these relatively cheaply I'm not sure these couldn't find the exact cost of this one so if anyone knows the cost are back in the day then please leave it in the comments down below so there it is the MCS 85 system design kit until 1976 so what are you getting the kit well you're gonna get the bare minimum to get a processor up and running you're going to get the processor itself the 808 e5i II for those playing along at home copyright Intel 76 fantastic and of course you need a monitor Ramat slash bias however you want to think about it we'll talk about these in a minute and you need some RAM so you need Ram ROM and of course you need a keyboard and display to interface with the things so this is both a combined keyboard and display controller the 82 is 79 and you just get a couple of smaller interface chips a 74 LS one five six decoder and an address decoder up there and the set segment displays we've got six of them here and the keys as well there's their individual key switches and a bunch of our passive parts and the sockets because well you know you don't want to sold them directly into the ball because these processes might have been relatively expensive back then and the ROM and the RAM and you know Wow so who actually are bought these kids well you might think I'll people who are developing computers but that's actually not really the case of the vast majority of customers for these kids would have been looking at using a processor to add intelligence in quote marks are to their new consumer product or their industrial control product or something like that so they needed a processor to do that so they would have bought this design kit to get them up and running and hence why it's gonna have a large prototyping area as we'll see when we take this puppy apart now because this thing is mint-in-box I'd probably get death threats not that I don't anyway you know youtuber but like if I tried to assemble this thing yeah the hate comments would flow so tada here's one I've assembled earlier well I didn't assemble it I'm a nice to procure another one which was already assembled ah thing of beauty joy forever now I think this one is a later model because look it's different at the top here since this system design kit is different and it's just got until up here it doesn't have copyright 1976 anymore and some of the date codes on some of the chips although these could have been added later we're talking about 1982 it's got the genuine Intel sticker on the ROM there this one does actually have a few additions that you didn't get in the standard kit the standard kit only had the processor the ROM one Ram chip and the keyboard and display interface driver kit chip this one has got an additional Ram chip for a whopping 512 bytes total that's by it's none of that K rubbish 2k of ROM which came standard in the kit and all this extra stuff up here has been added this was this is a bus expansion driver section of the board and you can see that whoever built this is obviously are populated that but looks like they didn't do an awful lot with it because they just developed programs because look at this large prototyping area they didn't interface with this at all they've got some connector ports here which you could have gone off to your own products or you could use this large interface in area that got power strips down the middle like this and that's very nice to be able to prototype your industrial widget in the mid to late 1970s this would have been absolutely fantastic and you could probably afford to use this section because I don't believe the development board was very expensive so yeah if you need it another one order it you just buy another one you build up more circuitry various revisions of your hardware until you perfect it and then your design and layout your own PCB and Bob's your uncle yeah I know 85 based product look at the keypad down here speaking of which who designed this this is just absolutely ridiculous of course I've got hexadecimal of course a B here a through 2f here you've got six keys across here why not have a b c d e f that would have made more sense than half 0 1 2 3 4 5 6 7 8 & 9 up here that's not the usual arrangement like that is just why why would anyone do that I don't know anyway this one's had a little bit of an oopsie it did come with this switch but it broke off and there's a trace just flapping around in the breeze there so hopefully it still works but I can fix that relatively easy anyway this is to select between either keyboard mode either keypad at keyboard mode or our tty which is a teletype interface and there it is the TTY teletypewriter face which goes off to a D connector up here and you could whack in a D connector I don't think no it doesn't come with one but you could whack one in optionally and that would go off at a whopping 110 board 110 board nose 300 board rubbish and yeah you can hook that up to a serial terminal that were very common back in the 70s if you wanted to actually like view information on the honest screen instead of the limited six digits seven segment display here so the tty interface is basically just a serial port that you're familiar with these days the 110 baud limit on this would have been a Jew to the 80-85 on this it wasn't the limit of the terminals at the time the dec VT 50 and 52 that came out in 1974 so two years before the 8080 processor here so that could go up to 9600 baud and then the vt100 a classic vt100 terminal came out which supported the ansi standard which then took off that came out in 1978 so two years after this but yeah they did have our terminals back then you'd have keyboard and display Wow 80 characters by 24 lines incredible oh I totally forgot to show you the documentation that came with this assembled aboard Intel Puerto Rico Adami Puerto Rican viewers fantastic wonder if they're telex still works dear SDK 85 customer Intel he's pleased to provide you with the enclosed 80-85 system design kit we appreciate the opportunity to ride the equipment aid to aid in your understanding evaluation of the 80-85 microcomputer as a supplier of high technology equipment intel is committed to providing design aids that will simplify your evaluation process and shorten your development cycle before proceeding further please take a look at the following checklist the design kit user's guide has very complete step-by-step instructions follow them closely review the assembly language reference before attempting to write programs special note please be advised that the Intel service hotline numbers on the top of page in the system design kit are incorrect the correct numbers are there you go anyone want to call those numbers and see who answers the 80-85 is a very powerful yet easy to use microprocessor allowing you to pursue cost-effective micro computing intel is committed to making your 80-85 experience both pleasurable and profitable back when they used to provide schematics those were the days absolutely fantastic that not double-sided oh you view that in glorious 4k who's responsible and I wonder if they still work there hmm and an overlay diagram Bobby does lie so before we power up this bad boy and see if it still works after almost 40 years we'll get to that stick around we have to talk about the 8080 itself and the history or at least I want to because I'm a bit of a computer history buff so this bad boy here the 80-85 released in March 1976 and only discontinued in 2000 so absolutely remarkable to get like 24 years out of a like a single micro that you can continue to buy absolutely incredible do modern ones are like do they have production times of 24 years unbelievable and live it in the comments anyway it's an 8-bit processor hence the name 80-85 but we'll get into the history of why it's named that it's clock speed 3 up to a blistering six megahertz and that was really quick for the day uses 16-bit address bus has 6500 transistors in it on a three micron the process so by 6,500 transistors these days is like it's nothing that's head of a pin stuff but hey back then you know wait doubling the number of transistors on the silicon moore's law and all that sort of stuff it was yeah it was ramping up anyway let's go back to almost the beginning of 1970 when Intel of course released the classic four double o4 for use in calculators and primarily for calculators back then but also used in industrial applications too and then in 1972 a year later there at least the a table weight which is an 8-bit version of that and they also released the 40 40 but nobody really cared about that in 1974 what we care about in 1974 is that they actually released the 8080 processor and of course the 8080 is the classic chip that was used in arguably one of the first consumer hobbyist personal computers available which was the otehr 8800 but that didn't come around until January 1975 so it was the chip had been out for like a year before the old ter actually got around to using it and it was famously published in January and then Bill Gates certain well you know that started the Microsoft thing but in 1974 Intel weren't the only show in town you had the Motorola 6800 as well which came out in the same year and that one actually used it was really good because it used a single five volt power supply you got to remember the 8080 didn't actually use a five volt supply it required three rails plus five volts minus five volts and plus 12 volts so you know that really was a pain in the arse and not hugely compatible with you know all these five volt TTL types stuff coming on the market so yeah that's where these 6800 kind of had an edge at that stage but also in 1974 if you didn't want to use a microprocessor like this which required external ROM external RAM and you know stuff it was a multi chip solution hence the name processor it was just a processor if you wanted what's now known as a microcontroller the first microcontroller came out in 1974 as well I've done a video on this the old mullen game used to use it it was the Texas Instruments TMS 1000 the mill and used the TMS 1100 but anyway Tim is 1,000 the world's first microcontroller came out in 1974 as well so if you wanted to develop a little smart sort of widget back then and you could fit in the constraining constraints of the microcontroller then the TMS 1000 was a neat solution and it was only a couple of bucks a pop and so that was quite nice but if you wanted any decent sort of processing capability you had to go for a micro processor like either the 6800 or the 8080 and have external memory and ROM and the whole works but generally back then people weren't making small stuff you know as I said make is still making big like industrial controllers and other sorts of stuff where you know you needed the extra processing power of this so that was pretty much the only game in town until 1975 when the classic 6502 came out and that was a low-cost 5 volt CPU but it really wasn't used in anything in 1975 it was out but it wouldn't be a year later until 1976 when the Apple one started to use and other computers started to use the 6502 especially in 1977 with the pet and the Apple 2 and the Atari 2600 and all those sort of ones 1977 as when so things started to take off but I'm getting ahead of myself so even though we had at the 6502 in 1975 there were no like mainstream computers around using the thing I'm not sure if you were around back in the day were you using 6502 in any like industrial applications or something like that anyway in 1975 Intel realized yeah we have to come up with you know this single 5 volt thing seems to be a hit have to come up with a single 5 volt controller so what do you call it well the other one was the 8080 we'll call this the 80-85 the 5 means 5 volts only and they finally released the 80-85 in March 1976 but also famously in March 1976 a another company called zilog were working on the z80 they started that in 75 as well and they came out with the z80 in the same month as the 80-85 came out and unfortunately for the poor old 80-85 the z80 was just a better solution for all sorts of various reasons it was like multiple manufacturers could sell it and things like that so the z80 really took off as the processor of choice for various personal computers from then on the 8080 I don't know a trying name computers that used the 80-85 you have to sort of go to 1983 with the Tandy trs-80 more trash 80 model 100 which used a CMOS version of the 80 85 the 80 cat5 and zilog didn't out with a CMOS version of their processes at 80 processor until well after that so but you know pretty much I don't know the model 100's probably it for the eight famously for the 8080 but that was we used well into the nineteen eighty-three well through our probably most of the 1980s still in the model 100 but all the motorola fanboys dave what about the 6809 yes sorry that didn't come out until 1978 so you know it was used in quite a few pcs on the market and things like that but yeah until with their 80-85 pretty much ruled school so like the embedded market I don't know why cuz they had better tools people were familiar with it with the art from or the for double-a for the 8 w 8 the 40/40 the 8080 they were just you know so they just took up the 80-85 I was pretty much like the embedded processor of choice back then so hey what's your favorite the processor of the nineteen seventies is it the 80 80 the 80 85 the zero 80 6502 6809 6800 let us know in the comments down below flame away anyway our old friend here the 8080 that was superseded by the 8086 and then of course they did the lower-priced or easier to interface lower cost solution that was a course the 80 88 which was used in which had an external 8-bit architecture and could use all the 8-bit chips hence the name 80 88 as opposed to 8086 was a 16-bit architecture anyway that was famously used in the original IBM at PC and well the rest is history but as was common back in the day the 80-85 and all all the other processors from Motorola and dialogue and other they also came with like many different support ships to build entire systems the 8080 here's a list of like I think that's about three dozen or so and different companion chips that help you build up the you know any sort of industrial or embedded or PC in a consumer device computer that you could possibly imagine they had GPIB controllers and serial ports and all sorts of you know really whiz-bang accessory chips for this thing to build up complete systems alright enough of the history lesson let's power this thing on and see if it still works all these years later now the manual watt says a 1.3 amps nominal supply that seems a bit high to me I'm so anyway I've set my current limit to 1.3 if you're powering up like old stuff like this and you you want to be cautious I'm I probably would have like set like 500 milliamps or something like that and you're not really gonna damage it if you set to lower current limit if the voltage is just gonna drop and it's just not gonna work basically so yeah better safe than sorry so you definitely don't want to go over the rated limit and looks like the previous owner had these wires in here already so it looks like that's how they powered the thing up looks like there's one are 10 of them in there so apart from that I think all the rest of them Ceramics so there's nothing really and that should have gone wrong with this so unless there was some other fault I kind of expect this to work confidence is high I repeat confidence is high confidence is high I repeat confidence is and we don't need the minus ten volt rail there that's only for the teletype interface which I'm not going to use all right I've definitely got the polarity around the right way let's pair it on and tada hi 80-85 we know winner chicken dinner geez that's not very bright but yeah old school displays genuine HP's for those playing along at home and that's drawing just over a nap there so no worries so five watts are nominal but as I said this actually has some extra port expansion here and I'll warp in extra 256 bytes of RAM now these are chips by the way these RAM and ROM chips these are very interesting these aren't just RAM and ROM they actually contain data latches as well in them so that's rather interesting that was just part of the 80-85 system so yeah you couldn't you couldn't just right before I believe you can just replace this like with any old ROM you've got actually use the genuine until ROM or compatible if there were any I don't know now speaking of the ROM what we've got this is called a monitor ROM and it's kind of sorted different to a bias a bias does more stuff like bias on a modern computer a monitor ROM is just designed to have a simplistic keyboard and display interface so that you can just interact and monitor all of the addresses hence what was called monitor ROM so you can it's basically like just like a peak and pokey type of thing for you peek and poke fanboys but anyway reset it displays 80-85 assume the dash is correct there and it's got a dedicated vector interrupt a button that's nice we'll actually use that in a minute are the board's a bit how you're doing let me prop it up assume this is a hundred percent working so we should just be able to jump into a memory address and actually enter code that way so sub st is a substitute memory or type in the memory address now 2000 is the memory address here's the memory map over here mm is where the RAM actually started so we go mm and we go next and f7 is the current data in there but we can overwrite that with you know a a something like that and we can just go next and it will increment to the next memory address and that's what's there and we're basically just overriding what's in memory there and if we want to execute the program we just ended at the address 2000 we just go go mm like that and execute and well it's it does nothing because we type the random stuff let's actually program in a program let's see if we can get the suck at account all right so let's reset substitute memory 2000 next 31 8 3 D okay 3 C 1 C 5 C 1 C 3 now here's where we want to jump to another address 20 a d 4 so substitute memory and into FB d 5 is 76 and C 9 and that is our program whoo-hoo ok so we'll just go back hit reset here that won't erase our program it doesn't actually reset the memory just resets the processor yes this is RAM so it's volatile so if you remove the power you will lose your program oh well none of that flash or even a squared prom rubbish back then so yeah we can reset that and to run the program we want to go go mm and fingers crossed execute counting and we should be able to our vector interrupt that to stop it yes Victorino app was supposed to stop it it was supposed to be able to resume hmm now we can actually change the speed of this thing with by changing the value in address twenty ten so we go substitute many memory 2010 like that and next and it's currently got eighteen I'm not sure if it's faster or slower so let's just go ten shall we so next go to thousand execute there you go it's that faster yep and if we put the value of one in there should be really quick go 2,000 execute Wow blinding speed we can mine some Bitcoin on this sucker so what speed is this bad boy running out well it's got a six point one four mega clock which is actually divided by two internally which gives a an actual hour clock speed about 3.0 7 2 megahertz but the processor can't do single cycle in well okay instruction cycles vary anywhere from like one to five clocks I believe so depending on what it's actually doing so yeah not single cycle instruction stuff so you're not going to get 3.07 two million instructions per second or MIPS it's not gonna happen but you know it's pretty good for the day 1976 and if we probe the clock pin pin 37 today there it is 3.0 7 2 megahertz so the neat thing about the 80-85 is that it did have a clock out pin that then you could use you could like it had an internal oscillator for starters and then it divided that by 2 and then you could use that clock pin to drive other synchronous external stuff in your system neat well it's neat for 1976 so there you have it that's the Intel MCS 85 system design kit from 1976 I hope you found that as interesting as I did and of course it still works idea there was and never any doubt really I mean these chips are just so robust like a multi micron process technology they're just yeah and not these newfangled things but anyway you take for granted like just buy no Mike control a kit these days for like a couple of bucks delivered and all software's free and everything else in there's tons of tutorials and it's all flash program memory and you know nothing like this old-school microprocessor where you had to store it in volatile Ram I guess there you could actually have a battery back you could hack in a battery back up to this if you were desperate is to keep your program in there but every time you wanted to test out your program you have to enter it you know some you know decade manager came along and accidentally bumped the pair or something like that if you lose the day's work just programming this thing so there might have been like external storage solutions I'm not sure but anyway yeah you just enter it in I think keypad it's actually pretty quick once you've actually got your list into actually you know enter it in just bam bam bam bam you know automatically increments to the next address and you know you just type in the numbers and and that's it but yeah if you make a single mistake you cut my guts up and your program doesn't work or it's you know buggy so you just have to go through and check each address and of course it comes with a full human debugger you can come up with their and good single step and check individual memory addresses and stuff like that and well that's what you have to do but anyway yeah to develop programs for this you would use the intel intel ik system pretty much there might have been other systems available at the time to actually you know assemble your program and things like that but yeah this is how it was done and then you program a mask ROM that we've got here all right when was the first EEPROM anyway certainly weren't electrically erasable you know get your UV light out thank you very much leave it in the comments if you actually had one of these and you played around with this is unfortunately before my time but I can still certainly appreciate this it's awesome and I mean just imagine this back in the day this would have been like absolutely phenomenal and please if you know how much this thing cost I believe it was actually pretty cheap so like because Intel just wanted to get you into doing this and I believe like just regular regular Joe average could just buy this from Intel and you could develop your processes back then so yeah fantastic so also leave it in the comments if you know what the equivalent systems were for like the 6502 and the 6800 the 6809 and things like that the z80 and did they have like equivalent things I mean the Intel was it pretty much became the de facto standard for like embedded products and things like that because maybe because of their support and their Intel ik design programming system and things like that perhaps so anyway I hope you enjoyed that if you did please give it a big thumbs up and as always discussed down below and over in the comments and check out my library channel I'm like 24,000 subscribers over in the library channel still going gangbusters fantastic catch you next time [Music]

Channel: EEVblog

Views: 56,501

Rating: 4.93994 out of 5

Keywords: eevblog, video, intel, 8080, intel 8085 microprocessor, mcs-85, intel design kit, intel processor, vintage computer, retro computer, microprocessor, embedded processor, intel 8086, intel 8088, 8 bit, 8 bit processor, altair computer, 6502, 6502 processor, z80, z80 processor, apple 1

Id: SBkW_pzhUSs

Length: 29min 59sec (1799 seconds)

Published: Wed May 27 2020