Hi. Imagine it's only 1981 and you're a business person and you wanted one of these newfangled personal computers? What did you want? Well, you wanted something that was affordable, Maybe something as portable, Definitely something that ran on the latest standards of the time, and definitely something that came with all the business software that you needed. Who delivered animals, born delivered, and we've got one. This is the baby that you wanted.

the Osborne one. Wow It doesn't get much more groundbreaking than this puppy. Tada. Look at this.

It was an absolute revolution in its day. The Osborne one. Let's check it out. People's jaws dropped when Adam Osborne released this thing in early 1981.

It was basically the world's first portable computer or luggable computer designed to basically fit under an airline seat so that you can actually carry this thing on a plane. You're a business person. This was the Ducks guts and it was released at the groundbreaking price of seventeen Hundred and Ninety five US dollars. What's that? About Four and a half or five grand in today's money.

But the thing with this is that it came with all the software. It came with a word star which was the word processor of choice back in the day. It came with a spreadsheet super calc I think it was. It came with the D base to it ran the Cp/m operating system which was leased and at the time remember, this is early 1981.

The IBM PC didn't come out until late 1981. So basically CPM was the standard. It wasn't only until a year or two later that Dos Pc Dos Ms-dos started to take over. So this ran the standard operating system and it came at an incredible price.

I People joke that you basically got the computer for free because the software was worth about the same as the computer. Wow But as far as actual computers go, it wasn't that right. It wasn't fast, it wasn't powerful standards na the process of working in understanding four megahertz tiny five inch monochrome screen on the thing 52 by 24 characters I Think it was which was software mapped into a large 128 by 32 screen Jool Floppy drives in it. but there are only single sided 90 KH couldn't that wasn't even back then.

That wasn't a lot of data to actually store on these things, and it basically wasn't really expandable. so there's no modem building or anything like that. So basically it was a pretty bare-bones CPM computer. but the fact is, it was at that price point and you got all that software for free.

So businesses thought this was the greatest thing since sliced bread and Adam Osborne thought oh, it might sell 10,000 of these. They ended up selling 10,000 a month. and it was designed by the legendary Lee Felsenstein who you might know as designer of the Soul Computer and also the original moderator of the Homebrew. Computer Club He's the one who ran the meetings and sort of organized them and kept all the nerds under control.

So an absolute classic computer. classic time. But it didn't last. Whilst this was a very successful computer, the ultimate failure of the company not too many years later led the industry to coin the famous term the Osborn Effect And this is where Osborn basically released details or rumors came about that they were developing this new computer and what happened.

Nobody bought this one, they held off purchasing so all the computer stores were left with stark, unsold stock and things like that. People were holding out for that new machine that coming out, and ultimately that played a fairly large part in the ultimate bankruptcy of Osborn Computers. So the Osborn Effects still a very popular term today to mean that if you mention your future product release details of it, then it can have an impact on the sales of your current product. So just beware.

many a company is I come and gutter because of that I know you're saying Dave's stopped you up and we want to see inside this puppy. Well yep, you know we say you're only Eevblog. don't turn. Oh no, I'm taken apart.

One of the most remarkable things when I first got this and took it apart is just how big and clunky this keyboard is. I mean why does it have to be this thick? I mean I know it's got nice. you know, full travel. Well actually not really full.

travel there anyway. Um, you know it's got a real keyboard on it, but why it's got to be that that hugely thick is is beyond me. I Don't know. It's absolutely enormous and it sort of adds to the size and the bulk of this thing.

I Mean it is not really that big a computer, you know, like in terms of the fit and entire CPM computer in here with five and a quarter inch are four to five and quarter inch full height drives and and everything else. it's quite fine. but that keyboard just adds so much to it. Wow So if we have a look at the front here, we've got a standard that nought point one each header for the keyboard and the keyboards remove all.

That's a very nice touch with the ribbon cable. Not sure if they had any long-term issues with that, though. It turns out they did have issues with the reliability of the ribbon cable going across as you'll last see when I tear down the keyboard later and they sort of changed it to this curly type with the right angle attachment there in future revisions of the unit and it looks very industrial with it. You know, a little Pokey five inch our CRT screen here.

that big huge five and quarter inch full height floppies in here i early 81. Did they actually have half height five and quarter inch discs available? I'm not entirely sure. but anyway, they went with the full height ones and that's obviously the huge bulk of this product. They could have made it.

you know, like like half that height if they actually used or almost. You know, if they used a compact 5 and quarter-inch moved the screen down, whatever. redesign the board or whatever. You know, they could have made this thing a lot smaller.

But anyway, we have these two little cutouts here. Obviously they're designed for your discs. so your five and a quarter inch floppy dish it or store the in there and then you'd whack them in there. It couldn't.

Of course you had to put the disk in to boot up. CPM Yeah, it wasn't built into ROM or anything like that. We've got a modem port over here which is basically a serial port. It didn't have a building modem, you had to have an external one.

standard D 25 serial Rs-232 good old I Triple E Four Double-a the HP IB interface a standard which you can use as a parallel port for driving printers. I Think they had like a printer adapter and staff of course the keyboard and brightness and contrast for the CRT external video. I'm not sure if anyone actually used the external video, but they might have I do not remove while power is on. Well, let's whip that out.

and that was a card edge connector but a big fat reset button that's sort of not really recessed. but you know I guess it would be hard to hit that one accidentally. And there's an external wire 9 pin D connector here labeled bat and that must be for an external battery. or don't think I've ever heard of anyone using an external battery with this thing because it was mains power, did not have a battery building.

so while it was portable in quote marks, um, yeah, it was not the world's first battery powered portable computer and we've also got external RCA socket here, presumably for the external monitor. but like yeah, I Don't know anyone who actually used an external monitor did with this thing. But anyway, there's the bad shot for you Badger aficionados. Let's have a look at the back of this baby.

There's not much at all. this one. the carry handles gone all completely crusty and rusty. So Yad probably had like a proper leather strap or something on there.

and you've got mains input. That's it. This thing basically was not expandable and for those playing along at home. Serial number: a 20,000 370 given that they sold like 10 or 11 thousand of these in the first month.

I Believe Could this be a very early unit? Well, there's only one way to find out. Take it apart. So this thing was actually designed to be fairly rugged and actually survive drops I believe. But so so we expect maybe to find some sort of cushioning support for the CRT Perhaps.

Anyway, we'll find out because there are, you know, many reports of this thing actually surviving all the rough handling you know, taking on business trips and planes and and stuff like that. So it was famously designed to fit under an airline seat. and I think that might have been one of Adam Osborne's first star requirements too Early Felsenstein was that hey, I want this baby to fit under an airline seat? This is a business and machine. Real business people.

They take thick. They take there our personal computers on the airplanes and there's one thing you'll notice with the Osborne one is that it is actually fanless. There's some grills here on the front, but yeah, there is no fan in this thing. So apart from the floppy drives and silent operation beauty.

And of course, this isn't the original color of this thing. It was actually white, but it's a yellowed. This is a classic case of bromine, a fire retardant material in the ABS our plastics of the day in these early computers. Very common for old computers like this to turn yellow.

all right. So let's open this thing up. Got the knobs off with the grub screws and there will be a clip. There's gonna be a cable attached to that.

but today, apart from that, we're in like Flynn. It's a bit of dust inside here, but not a huge amount. But of course given that it's our family's you wouldn't expect a huge amount in there. So they've got like this: seems to be a lot of wasted space under this main board here.

I mean this main board is actually on an angle so it slopes down towards the back. Here it's got these metal brackets, but yeah, isn't it's a fair bit of wasted space inside this puppy. So I'm not sure why they couldn't lower the floppy drives down I Know they did use you know, this space in here and here to hold the floppy drives, but you know they could have had an external pouch for that and made the thing smaller perhaps? I mean you know there's a lot of air in there and there, so it's not the most efficient layout. Oh yeah, we got some.

got some crusty stuff. Now as for the CRT mount. it is separated from the outside of the case, so it seems to be fairly rigidly mounted to the inner plastic, but that's going to allow some a reasonable amount of shock absorption. You see that fold over like that, so that's you know, an interesting sort of mechanical solution for mounting the CRT in there, but they certainly you know it's not what they've whacked on a like it's some sort of a spring shock mount or something like that.

I Don't think no. I'm not sure how much I helped Lee Felsenstein head on actually designing this thing, but you know it could have been a fairly one-man bandish type operation. So you know I probably wouldn't expect a huge amount of industrial in a big company. optimization and getting it right down they probably went I Want it to fit under an airline seat? That's the requirement.

this is the envelope. make it fit and you know they would have had a tight timeframe to do it in. So yeah, you know it's not necessarily the most optimized solution. All right.

I was taking the screws out the back, so hopefully and the side here? there's just two screws there, so hopefully this inertia Z will just pull out. That's the plan anyway. Tip it upside down and lift the whole lid off. That's the key.

Just wiggle it out like that. We can. We can wiggle wiggle wiggle. Yeah, come on.

Otherwise, gonna have someone to help you I think But ultimately I think we are in like Flynn Arrow that is. So that really is quite fascinating how its inner chassis is just this folded ABS plastic I presume it is in a shell like this. Actually, it's probably kind of clever in that this would be really cheap to manufacture. I mean it's just basically folded plastic like that and it gives some support in there.

Some give for the internal white CRT which does seem to be our has I've got rubber? No, no no I think it's rigidly connected CRT is rigidly connected. but then they. they give some give to the outer shell. So yeah, it's just.

could you use the word clever? I don't know, but certainly are clever at a low cost that's for sure. I think if we take a look at the bottom, we can see the classic double-sided layout here. All the most of the traces on the bottom are going in the horizontal direction. You'll find that most of the traces on the top side of the board going in the vertical direction like this.

None of this four layer rubbish back in the day and obviously all our memories over here. CPUs in here somewhere and that looks like a quite a decent layout typical of the day. I Don't know if that Lee himself actually laid out the board, they may have had somebody else do that. but yeah, that's pretty neat.

and of course, absolutely. Classic rolled tin plated board here and then the solder mask over that. hence all the little all a little crinkly solder mask like that. Jeez.

I Don't miss that solder mask at all. Um, these are you know, famously back in the day you get poor quality I solder mask the the turn like there resin technology and all that you know. the materials technology wasn't that great. Sometimes they'd peel off and it'd be pretty horrible.

made in the United States of America and take those four screws off, Tada, there is the main PCB that actually comes apart quite well. Okay and here's where all The magic happens. Our tube or construction main logic board down here and it looks like this one is most likely the video board did giveaway on the video board. We'll take a quick look at that.

Obviously, we've got our character generator ROM Here we've got some two, six, double, one-sixth they would be the character the the video. RAM and this connector over here is the coax that goes off to the RCA connector. so that's for the external monitor. But well, this is how you do and check this out.

I Mean you know. nice board. You know they use the dip socket here. Board the board interconnect with those you know down here as well.

so there's three board aboard interconnects that's really nice and they've gone and ruined it with this completely. How you're doing wiring going over, soldered to individual pins and vias all over the damn board. What? Lee Seriously, What were you thinking? I Mean you must have been desperate to get this thing out. Oh well.

I Mean this actually screams of PCB Layout Desperation: Actually Like: I'll go to point up here. Point up here. a couple of points down here: I Can't get them right down to a connector down here, but you know a lot of these are pretty close What: You couldn't route those down here, but you know they might have run out of routing space. but you know that's the PCB layout persons job as to I figure than that all out and like they've made the conscious, you know they did the border board interconnects here, everything's fine and then they purposely had the classic dip our ribbon cable arrangement going over to various points with like last-minute change and they didn't want to Reese pin the board or what or whether or not these ran out of routing space to be interesting to know the story of that one.

and I might actually I'll see if I can find some photos of some later model units as well. Maybe they might have fixed that in a later design, but you know, serial number twenty thousand I Think this is one of the early units. why do all my Brazilian viewers are there any TF ABS left in Brazil I Wonder Hmm. but of course this is not just the CRT board.

it's also got the Z80 processor in this case it's an NEC job the D7 ATC but it's a Za D equivalent processor. so it's interesting that the main process is on here and you'll see that actually goes into a socket right down to the second boy which is rather interesting. So it's a fascinating decision that went into putting the processor on this secondary board which has to do the display stuff and not have it on the main logic board over here. That's really weird.

I'd love to hear Lisa you know rationale behind all that. So underneath our video board, we can actually see this is the main as that ad processor socket here. and then we've actually got our roms. so there it is.

we'll be able to I'll see if this puppy works later. but I'll I get out the EEPROM reader and actually extract the data from that and I'll have it on my website for those playing along at home. So here's our serial number and our revision. It's upside down here.

This is revision J and a link in the service manual for this thing down below. Very comprehensive service menu. It lists all the revisions of the board and they did a complete layout and everything else that talks about manual wiring changes that we've actually you know seen down here and things like this. but this is one of the released boards after November 1981 rev.

J's so white still has all that point-to-point wiring. not entirely sure cuz like a Rev version of the board was a complete relay out of the board. and they even mentioned a later I think 1982. there was a complete multi-layer version of this board to meet our FCC requirements because this double-sided board wouldn't be that terrific.

You know there's no big ground plane down here so wouldn't have met the new our FCC requirements and quite a quite a few computer companies of the day actually had issues with SEC compliance. and you know you hear stories about the older trash shady computer I think it is like you turn it on Tandi Trash 80 that is Trs-80 For those who don't like the name, Trash 80 let you turn it on the interferes with you yeah, A.m. or FM radio or something like that. So yeah, so they went to a four layer board for this, but this is definitely one of the earlier double-sided layouts.

so other stuff around the processor here. the ROM of course and then some classic Motorola MC 6821 Pei or parallel L peripheral interface adapter sorry and then this ceramic package here. this Sabot 17 23 I Haven't seen that one before, but that's a looks to be the floppy drive our controller and no surprises because if you follow the money, follow the tracers from this floppy controller up here all the way across here. it's going to that ribbon cable which then goes off to the floppy drives and then next to that we've got a Motorola MC 68 50 that's our UART for our serial ports.

dead giveaway. If you show the traces going down there, that's going to our serial outputs here, both for the modem and the main serial port. And we've got a buzzer up here because well, we've got the build character on our keyboard so it has to go ping and this one thing which you'll notice that's not on here and that is your traditional battery backup. There was none of this CMOS bias rubbish back in the day and there was no real-time clock either.

so this thing couldn't even keep the time when you switched it off. And we can see right down here that this is actually a release rev F board. And here's our memory. Check it out.

The interesting thing about this is that look, it's all hickety pickety. They just got the chips from wherever they could. didn't matter the brand, the factory, whatever. At night they didn't buy these all at once.

they just the purchasing department at Osborne must have just got the cheapest memory from wherever they could and get it and then just whack it in there. Thank you very much. And of course we've got the classic bypass arrangement like this: You see the big fat power traces running under the memory like this, so they have a bypass cap on axial thank you know this radial rubbish and on each IC like that of the memory array and then some bulk tantalum stuff over here. Woah yeah.

Fire Starters 10 alums. And as far as the battery pack went well, there's no regulation circuitry around here. There's a couple of diodes to prevent reverse polarity, but that's about it so we wouldn't You would have had to Powell this thing like a BAC parrot through the board. so presumably that's a five volt battery pack or could have had five in 12 and then going off.

I'm not tirely sure of the details. There's also another thing missing here, and that is like a traditional our CRT controller chip. So I got the processor. We've got our character generator ROM our display Ram But basically yeah, no traditional CRT controller chip must be doing it all manually.

As far as the rest of it goes. Yeah, look at our exposed mains wiring there, no worries. Hmm. wouldn't be too compliant these days, but back then, not a problem.

And as for the power supply, nothing hugely your special here. We've got a hundred and fifteen volt tap flapping around in the breeze here. We've got our power transistor on the side there. We've got a couple of do up a couple of axial diodes there with their heat sinks and rubicon caps there, thank you very much.

And as was common back then and still is today, I'm as tech components, Somebody else just laid this thing out the 1980s, so it's reasonably old. It's a rather interesting layout in that the mains is coming in here, through the fuse, around around around around around, and primary side switching and then the secondary stuff. so the mains input right next to the secondary output. anyway.

Hmm. fascinating. And we're of course we'd be getting our 5 volts out as well for the main logic now. Interestingly tucked away inside there that to me looks all the world like a thermal cutout.

Is it not one of those are thermal switches? Hmm I wonder what it's doing? Well, that's fascinating. I Followed the wiring. It actually comes out here and goes to the mains input. so it's a thermal cutout on the mains input.

Okay, and for all you floppy drive aficionados, here we go. It's a Micro Peripherals. Inc Model 51 is that manufactured up March 1982 and look I Love how they've got the calibration wheel speed wheel on here. 50 and 60 revolutions per minute to actually calibrate this using a our strobe light.

Fantastic. But yeah, the rubbers still in good Nick most likely still work anyway. Now you can see the head in there. You can see the gold tape under there single sided drive.

Now, rumor has it that they deliberately decided to go with a single sided drive instead of a double sided drive because they thought double sided might not be as reliable if somebody drops this thing being a portable computer and that limited the data you know capability to single sided disks. So yeah, I don't know the truth to that. but anyway, single sided only. Hmm.

even though double sided was available back then, they just decided not to do it. And as is classic for the day, there's not much inside your typical floppy drive. And I love the sector sensor here and check it out. there we go.

They have actually got that as just the look There it is. Tada. It's just got the photo sensor directly in there and just that does clips on. Oh, absolutely brilliant.

Wonderful. Tech Five and a quarter inch floppy I Miss it and you'll notice another sensor down in there. Hopefully you can see it in the darkness and that's for seen that there's a disc actually inserted in this thing now. I'd Love to get the CRT module out for you, but I've taken all the screws out, but it doesn't seem to be budging so I'm not sure what the deal is.

they're running out of time so I might have to leave that, but nothing too exciting. it's from Nippon Electric Co and well, yeah, it's a little 5-inch CRT Love the big power resistor. Oh now I have to know what the hell made this keyboard so big and thick? Nothing. Oh oh oh, we've got something up.

Some pins really bent to buggery there. What's going on anyway? Tech Inc Assembled in Mexico I Don't want my Mexican viewers. but yet. basically, there's a lot of, um, empty space inside this thing.

I Mean, they've made it ergonomic like this, but it's like it needs to be that thick and it's like no, no fail. Anyway, separately Merit keypad. look at this and the bell. you got to have the bell symbol got I Make it Go ping.

And the other ridiculous thing is, there's absolutely no strain relief at all on this ribbon cable is nothing to hold it in the back. That's just wow. That is crowd. So there is one interesting beast.

The Osborne One. Basically, the world's first portable luggable computer. wasn't battery-powered but I this was an absolute phenomenon. They practically gave the computer away for free with the software.

Hmm, go figure. Anyway, this was a revolutionary, groundbreaking product, but hey, it didn't last that long. Other models like our K Pro and other our portables came along fairly quickly after this. and of course, the classic Osborne Effect where they announced a new product and this thing.

Just you know, sales of this thing dried up and also rumor has it that when they went bankrupt, apparently all the employees just walked out with the units and security apparently didn't know like they didn't look like they were carrying out big briefcases or you know, something like that. So they apparently just walked out with all the yeah stock. anyway. I'm not sure how true that is, but at the fascinating tear down of this thing and I'd love to hear from Lee I'm sure he's still around what's he doing these days and the design of this thing, but yeah, it was popular back in the day, but didn't last very long.

but a truly groundbreaking product. So I hope you enjoyed that teardown. I Got some high-res photos over a TV blog.com link down below somewhere. Check that out if you liked the video, please give it a big thumbs up and discuss it down below and over on the forum and all that sort of jazz.

I Will actually put this back together and try and pair it up I Think it actually stands a reasonably good chance of working giving it you know, 35 years old or there abouts approaching that. It's these old computers. Not much I can go wrong with them apart from our power supplies and stuff like that, but unfortunately I don't have any sloth is CPM floppies for itself I can't pair it up Oh like has he get it running anyway? Catch you next time I'll tell you what I Can't help but be fascinated by the physical construction of this thing Wow It's so kind of. We've been given the envelope as a designer I've been given the envelope and let's just make it fit.

Now just bend some plastic and hello, she'll be right. No worries, mate. And yep, oops, the carry strap broke putting it back together. Oh and yes, it does actually survive a drop of several inches onto the bench onto the CRT face.

No worries. All right, let's see if this puppy still powers up, shall we? Let's give it a bit. I plugged the mains. You know what? This is a 230 volt model so fingers crossed.

Whoa. how'd it go clunk? I Saw the lids I saw the lids. Come on. you can do it.

Come on these. CRTs take a while to brightness. Whoa. we're in I was born.

One look at that. Oh, isn't that beautiful Osborn One Rev 1.44 Copyright 1983 OCC Osborne Computer Corporation Insert this straight disk and drive am, press return. Unfortunately I have no way to actually produce a five and a quarter inch floppy, let alone one with the CPM at 2.2 on it. So it wouldn't surprise me if the floppy still work.

They might need a head clean or something like that. But yeah, I mean all the electronics still working? This baby's oh, do something useful Damn you wears a CPM five and a quarter inch floppy when you need one. And how quick does a boot that quick? Well, except when it's got to read the OS from the floppy which is CPM mmm-hmm So if we have a quick look at the ROM dump here, this is the main bias. ROM You can see the ASCII equivalent down here and you can see that we've got boot error there.

Basically just in here looking for little hidden easter egg texts or something like that. But here's the boot screen: Osbourne One Rev 1.44 Copyright 1983 That's exactly what we saw when we are turned it on. insert disk drive one press, return, blah blah blah. but that's basically all she wrote in terms of text in.

there. There we go. so we've got to see some keyboard key mapping presumably what's going on there anyway. not sure I can't see any like hidden Easter Egg like leaf Felsenstein was here.

you.