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You Won’t Believe What’s Inside These! (Actually You Probably Will)


Tearing down a Commodore PET, Commodore 8050 Disk Drive, IBM 5160 PC XT and a couple of IBM 5170 PC ATs to see what’s inside!


If you cast your mind back to October 2022, you’ll remember that I visited the Northwest Computer Museum, which was a brand new museum which had been under construction for a couple of years up in Manchester. And they were really, really looking forward to getting that up and running and open to the public. And I’m very pleased to say that the museum is now open and absolutely thriving, which is fantastic to see. And I’m really looking forward to going back and checking it out and hopefully making a follow up video.

You may also remember that they had a fundraising sale on at the time to get some pennies in to get those last few bits finished off, ready for the big launch. And me being the selfless philanthropist that I am, of course, had to make a donation and ended up coming home with a big boot full of computers. As you do. And those machines included these IBM PCs and of all things, a Commodore PET, which I know absolutely nothing about. But, hey, why not? Now, these machines pretty much went straight into storage as soon as they arrived because I just didn’t have the room to do anything else with them.

And it’s only today that I’ve had the chance to get them out and take a proper look at them. And I wanted to have a look inside and see if there’s any interesting hardware lurking within and also check out what kind of condition they’re in. And of course, bring you along for the journey.


So, here we go.

First up, we have the Commodore PET or the CBM 3032, as it says on the front. As you can see, this is a UK model with a 3-pin British plug on it. Apparently, and I’ve done some research on this, apparently this was released in 1977 as a competitor to the Apple II and the, you know, those early machines around at the time. And yeah, this is a very early model. So, this is a model 3032. And apparently this is an early keyboard as well. Like I said, I don’t really know much about these.

And from the outside, it’s in reasonable condition. I think the immediately obvious things are this, which is - this is metal, this top part - the bottom part is actually plastic. And that’s only one piece and undamaged, which is nice. But this is going to need re… I guess it would probably need powder coating rather than spraying. But, you know, it’s solid and it’s straight and true and I’m sure that’s rescuable. So that’s cool. And I think the other obvious thing from the outside is this sticker that says, “Do not power on, burnt cap.” And obviously that’s a result of the museum people testing this. So yeah, really cool. We’ll see if we can spot that when we open the lid. And finally, there’s just this missing key here, which I’m told was present when this was first put out on the desk at the start of the day.

But evidently, at some point, some dishonest person or perhaps some miscreant child has helped themselves to this very rare shift key, which is unfortunate because I’ve actually been watching eBay for these ever since and I haven’t seen one come up. I haven’t even seen a complete keyboard come up. So I’m not really sure what my options are. There is an aftermarket keyboard, like a mechanical keyboard project that can go straight into these apparently. But then obviously you lose the custom key caps and stuff like that. So still not entirely decided whether I want to go down that route, but it’s a potential option. So let’s open it up and have a look inside. My favourite feature of these, I have to say, is this. It’s like a car style bonnet stay.

Oh, I should talk about the screen actually first, just before we take a look inside. So the screen here, this is a green screen. And as you can see, it’s got really, really bad screen burn on it. I don’t think this is even English on here. I’m not quite sure what language it is - Possibly German? I’ll try and get a good shot of that anyway, so you can see what it is. And I’ve heard that the Amstrad green screen, I don’t know the model number of the monitor, but there is an Amstrad green screen monitor that is a straight tube swap for these. And I’ve actually been offered one in non-working condition that has a good tube, or we assume it has a good tube.

Now I’m not sure whether it’s worth repairing that, because they’re not worth a lot, especially compared to this. I’m not keen on sacrificing one piece of history to save another, so to speak, even though there’s that huge difference in the monetary value. So, I don’t know, this is the rarer machine, but I am on the fence about that. I suppose I can get this one up and running and see how it looks actually in use. And also, of course, have a look at the Amstrad monitor and see if it’s repairable. But yeah, so obviously we’ve got that screen burn on the monitor. And if we open this up, we can see the motherboard inside. I’m going to have to hold onto this, because there’s no way to prop it fully open.

And there’s this cable that’s connecting the keyboard to the motherboard. So this looks in quite nice condition, actually. The board itself looks nice and clean. This is our exploded capacitor here. And yeah, I mean, that all looks quite promising, actually. We’ve got the transformer here. This is quite rusty. And then we’ve got this big capacitor. I presume that’s a capacitor. I’m not particularly attached to historical power supplies. I’d rather be confident in my machines not exploding. But yeah, quite, quite nice. Quite nice rust free case. Maybe this could be powder coated if we wanted to put it back to original condition. But it’s not looking too bad, actually.

So yeah, that is the Commodore PET.

So along with the PET, I also got - again another UK model - I also got this disk drive, a Commodore CBM 8050 dual drive floppy disk. And apparently these are very rare and quite sought after. Not particularly useful in this day and age of SD card interfaces and that kind of stuff. Still a cool piece of history. So I guess… That’s a lovely noise! I guess it’s just a couple of screws to get the lid off and we can see what’s inside.

Oh, so there’s a board in the top which is still kind of partially attached. But there we go. That’s what the inside of one of those looks like. So we’ve got our two drives in here. That’s interesting. There’s like a full controller board on that side. But evidently I guess they use the same controller for each drive. So can you only use one drive at a time maybe? These have these… These are micro switches. I guess that’s to detect whether the disk is in the drive. And they’re really badly rusted actually, which isn’t great. Overall condition isn’t too bad. Interesting sticker there. Especially this board in the top. That’s in quite nice condition. Again, the transformer looks quite rusty.

Of course, with the modern SD card interfaces this is pretty much redundant. It’s just kind of a historical oddity. But if this was to go in a museum or whatever, of course, having it all present and in full working order would be quite nice. Oh, I see. Oh, I see. Okay. So actually I didn’t need to undo these screws in the back here. This is actually hinged, similar to the computer itself. So if I just look at those front two screws, the lid would actually just hinge open. So yeah, that’s clever. That’s a really clever piece of design.

So here’s something a bit more familiar to long-term viewers of this channel. This is an IBM XT machine. Is it a 5150 or a 5160? It’s a 5160. I haven’t got one of those. Okay. So I already have the 5150. I’m not entirely sure what the difference was with these two models. I think I’ll just quickly look it up… Okay, so the 5150 was the original DOS PC released in 1981, which I’m sure regular viewers of this channel will be familiar with, because I have one, a really nice one that’s quite heavily upgraded. This is the 5160, which came after that. This was released in 1983, and it’s basically exactly the same spec, except it has an internal hard drive and it has more expansion slots. So let’s take the lid off. And I haven’t actually looked inside this one, so I’m not quite sure what condition it’s going to be in.

But the case, oh, I should mention the case first, actually, just before we take a look inside. The museum actually had a load of these powder-coated, so this is, I mean, it’s got a few scuffs on it now from storage, but yeah, these cases are in really, really nice condition because they’ve been, like I said, a new powder coat, and it’s a really good colour match to the original colour as well. So that’s quite nice. If nothing else, if this isn’t salvageable, maybe I could steal the case for my 5150. So that’s just a look at the front. It’s not too bad. It’s a bit grimy, but it’s only one piece, and I’m sure that could probably be cleaned up quite nicely.

So here’s the inside. The back of the case here, there’s a little bit of rust around there, but again, it’s not too bad. It’s got the 64-256K system board, which of course will be a later one because this is a 5160. And this came with a 10MB Seagate hard drive as standard, and this is the original hard drive, so that’s quite cool. I’m not sure whether that will still be working, but they’re actually surprisingly reliable for their age, usually just a bit of oil and they’ll spin up again. So it’d be interesting to see if there’s anything on that in a future escapade. And again, a bit more rust on here, but that’s literally just on the case itself. The drive actually looks quite nice, so that’s quite promising. Of course, the power supply, I think these were uprated in this model. Is that 130 watts? I think the original 5150 power supply was something like 60 watts. So not really advised to put a hard drive in those because it wasn’t really beefy enough to handle it.

As you’ve seen, in my 5162, I actually gutted mine because I put a modern ATX PSU inside and kept the original looks. So potentially an option if I’m restoring this one. And then we’ve got the floppy drive here as well. I can’t see a model number on the floppy drive anywhere, but I imagine it’s probably 360K, given the machine’s age, unless that’s been upgraded. But that looks like an original IBM drive, so that’s probably the drive that came with the machine. So let’s have a look at these expansion cards. Now, as I mentioned before, one of the perks of the 5160 is that it has more slots. So we’ve got eight of these expansion slots in here. One, two, three, four, five, six, seven, eight. So we’ve got eight of these expansion slots in here, as opposed to the five slots that the 5150 had. And these actually weren’t referred to as ISA until later on. These were kind of, I think it was called PC Bus expansion system. No copying permitted. I like that. All rights reserved. Obviously that’s their way of kind of trying to fend off the army of clones that were starting to pop up by this point, around 1983.

So we’ve got, looks like a parallel, yeah, it’s a parallel card there. So that’s just to connect a printer. Nothing too exciting. Of course, later PC motherboards had all of this stuff built in, but these early machines, the board was literally just, oh look at that, one of the RAM chips is hanging out! Yeah, the motherboards in these early machines were literally just CPU, RAM, a little bit of logic to kind of tie it together. And everything else had to be on cards, all the floppy drive controller and hard drive controller and everything else. And even stuff like serial and parallel. So this one is connected to our Seagate hard drive. So it’s more than likely a hard drive controller. In fact, I’d be very surprised if it’s anything else! So that’s the hard drive controller card. And again, back in these days, stuff like IDE wasn’t sort of standardized and the cards were actually paired to the drives. And some of them use their own kind of unique communication protocols and stuff. I think the Seagate ones are generally compatible with each other. But then of course you had MFM and RLL and sort of slightly different technologies as time progressed.

But yeah, full length, 8-bit hard drive controller card, IBM branded. Very interesting. Again, that looks in quite nice condition. Apart from the filthy cables. Yeah, it’s quite nice. And again, this card is connected to our floppy drive. So that will be our floppy controller card. Very basic looking card there. It’s also got this big expansion connector on it, which I believe is for an external floppy drive. Or I know IBM also sold- I can’t remember that, I think the model number was the 5161, which was an external kind of a full PC chassis that you could actually connect to with a cable and then you could put a load of extra expansion cards in it. So maybe it’s a connector for one of those. But I think it’s probably more likely just for an external floppy drive.

Ah, so this is very interesting. This is a RAM upgrade card and these are 256. We’ve got two extra banks in here. And of course the chips on the motherboard are 64s. And an interesting thing actually about this is that the original 5150, this first bank of RAM was soldered directly to the motherboard. And these are socketed on this one. I actually desoldered mine in my 5150 and socketed it all just because I wanted to have the ability to replace the chips if they fail. In fact, I did have a RAM error on that and did end up replacing quite a bit of the RAM. But yeah, this is an expansion card. Got two extra banks here, 512. So that will take the system up to its maximum of 512. No, 512 isn’t the maximum, is it? The maximum on one of these is 640K. So a little bit more room for expansion. But yeah, with 256K on board, an extra 256K on here, that would take the machine up to 512K, which is quite a lot of RAM for 1983. But yeah, really useful little card this, one that I can just drop into other machines. So quite a useful thing to have.

And finally, what is this? So it’s a serial card. Async, yeah, so it’s an asynchronous serial communication card. So yeah, like I said before, serial and parallel ports on these old machines aren’t built into the motherboard. They’re on external expansion cards. And so we’ve got a parallel card and a serial card. So that would have been used to connect to potentially a mouse. But I think it’s probably a little bit too early for serial mice. But, you know, to serial devices - like probably a modem or something along those lines. So yeah, really cool thing yet again. And definitely taking advantage of these slots. So we’ve got one, two, three, four, five cards. So that would have absolutely maxed out the original 5150. But in this case, we’ve got slots to spare for future expansion, which is quite useful.

I see, we’ve got some bodge wires on the motherboard here. That’s quite interesting to see. And quite a bit of that rust around the back of the case that we spotted before. And the really cool thing about this, in fact, let’s actually zoom in on this. So if we look down here next to the power supply. We have the CPU and we also have a math co-processor. So yeah, we’ve got the 8088 CPU, which is the original one, which would be 4.7 MHz. And we’ve got the 8087, which is the math co-processor. So that was used for, you know, maths operations, 3D calculations and that kind of stuff. Obviously, you wouldn’t be running anything like modern 3D stuff on a machine like this. But anything that’s kind of computationally complex that requires the use of that co-processor. And with the right software, that would have actually made quite a big performance difference in a machine like this. Something, again, that I have covered previously on the channel. And I will link some relevant videos down in the description. If you’re looking for some further viewing on the topic.

I’m not going to take this sticker off the CPU - That’s just nice and original, isn’t it? “Granada Item Number”. But I can just see an AMD logo poking out there. And IBM actually used both AMD and Intel to manufacture the CPUs. Basically, Intel didn’t have the capacity. So they ended up outsourcing some of that to AMD. And yeah, that’s how we ended up with AMD CPUs. And a lot of these IBM machines use them.

Oh, my back!

Now the first of a couple of IBM 5170 PC ATs. And Joe from the museum actually found that this is missing its front panel. And Joe from the museum found this after I left and very kindly posted it over to me. So I have a front panel for this as well. But anyway, here it is, the IBM 5170. So if you’ve heard the term AT, as in an AT keyboard or an AT power supply, this is the machine that that technology was invented for, the IBM PC AT. And as you can see, this has got another one of those powder coated cases. And again, there’s no screws in this one because for some reason they took all the screws out and didn’t put them back in. But I can hardly complain. I’ve got plenty of computer screws, so that’s not a problem. A really nice condition - that’s just cat hair on there - really nice condition powder coated case. And a machine that I didn’t already own, and I’ve actually got two of these. I’ll show you the other one in a second. But let’s take the lid off and see what we can see inside.

So a much more modern machine than the 5160 that we’ve just been looking at. This is a 286 CPU. There were 6MHz and 8MHz versions of this sold. And if you’re a regular viewer of the channel, you may be familiar with the IBM 5162, which was kind of a cross, kind of a hybrid between the two and quite a rare machine. And I did a series where I was fixing up and playing with one of those to see how fast I could get it to go, because notoriously the clock speed was crippled by IBM in the actual BIOS itself. So that was quite a fun project. But this is the 5170, the big daddy, the big brother of that machine. And as you can see, a much more modern machine inside. It’s got a 512K system board. It’s got these 16-bit ISA slots. They were ISA by this point, although, of course, backwards and forwards compatible between the two. And it’s got one of the old original. I think there’s a couple of those actually. Yeah, it’s another one there. So it’s got two of the 8-bit slots for five, six, seven, eight of those in total. We’ve got a huge great power supply here. You can see all of the voltages and the ratings for the various pins on the connector. This is an AT connector. It’s actually the same connector that they used in the 5150, but, you know, it’s an AT. So it’s an AT connector. We’ve got the hard drive in here, and this is quite the sight to behold! Let’s see if I can get this out. Again, no screws. And wow, would you look at that? So that is what’s known as a full height hard drive.

If you’ve ever heard of a half height drive, which is what most of the drives were, you know, sort of throughout the 90s and stuff, that is - that’s a beast! Yeah, wow. So that’s a Seagate ST4038, and that is a 31MB MFM hard drive, and it has its own controller card as well. In fact, it looks like this card handles some other stuff as well. Maybe the - I think that’s an integrated floppy and hard drive controller. So we’ll take a look at that. And the other funny thing is this drive actually- I didn’t have to unplug that, but there you go. This drive actually has its own grounding cable to connect it to the case to actually ground it, which is a really serious looking piece of machinery that. And speaking of the case, this case is in really nice condition. I don’t know if this has been re- powder coated or what, but there’s not the slightest spot of rust or damage or anything on that. That’s in really lovely- I mean, that’s practically brand new condition, isn’t it? They must have. You can actually see some old rust there that’s been coated over. So yeah, this one’s been redone. I think. Oh, just got a glimpse of the bottom as well. They look like brand new cork feet as well, which of course is what would have been fitted originally. I think that case has actually been restored and repainted. So really nice basis for a really nice PC AT there.

So just flipping it over. This battery holder has just flopped out from under there. I don’t know if that’s original. I would expect that to be. Oh, I see. That’s got a 9V connector on it. But yeah, that just takes four AA batteries and that’s obviously for your BIOS settings. So very cool. No batteries in there. No rechargeable batteries. No Varta damage or anything like that because of that kind of off board battery, which is really nice. This board’s in really nice condition. Let’s just take this out… So this is a 16-bit card this time around. Just unplug that. That’s our front case lights - or at least the hard drive light. And that is - it’s got the WDC chips on it. So that is our integrated hard drive and floppy drive controller. So that’s MFM to go with that big Seagate drive.

So just under here, let’s zoom in on that. We have this is a 6MHz 286 CPU made by Intel and we’ve got the timing crystal for that there next to it as well, which probably can’t quite see there. It’s just underneath the drive bay. So really nice board and yeah, should be really, really good foundation for a nice PC AT. No expansion cards in here. I see somebody’s taken the parallel and serial cards out at some point, but no problem at all replacing those, especially as they’re 16 bit. So some later, faster ones can go in there.

And finally, our last machine for today is another IBM 5170 PC AT. This one looks like it’s in a slightly different configuration. It’s actually got two floppy drives in which we’ll take a look at. But yeah, this unrestored case. So this hasn’t been powder coated. This is kind of as original. Hopefully you can see that the colour match was close on that other case. You know, I think they did a really nice job of those. But let’s take the lid off and see what’s inside. It turns out there’s actually a screw in this one. So again, I haven’t actually looked inside this. So it’d be interesting to see what’s in there. It feels very heavy compared to the other one. Guess because of those floppy drives. So we’ve got something broken off there. I’m not quite sure what that is. Again, this bottom case is really nice, really nice condition. And I think that’s original because there’s still clear patches on here that haven’t been coated. So I think that’s actually original condition. Looks like somebody’s been fiddling with that.

Yeah, so we’ve got the two floppy drives in here. I’m not going to take those out. You know, better off staying in place for now. They look like later drives. I’ll see if I can look up the model numbers for those and work out what capacity they are. And we’ve got one of those full height hard drives in here as well. I see there’s actually- so this one has a metal bar across the front to stop the hard drive falling out, which that other case didn’t have. So that’s quite handy to have. I’ll just show you the bottom of this if I can. The bottom of this case, we’ll just have a quick look. These feet are all over the place. So these would come unstuck at some point. We’ve got some big scratches in here. So this definitely hasn’t been restored like the other one has. But still quite nice clean condition, not quite as clean as the previous one.

I’ll just zoom in on that. And again, we’ve got our 16-bit slots and we’ve got the 8-bit slots. We’ve got this. This looks like a very similar combined hard drive and floppy drive controller. So, yeah, this looks like a really early one. We’ve got a 192W power supply. And again, that’s slightly different to the one in the machine that we just looked at. This is- I’m working on the assumption that this is a 5170. I haven’t actually looked at the label on the back, I’m not aware of any other models. No, it is. It is a 5170. OK, this is the - earlier I was talking about the external chassis that you could get, that you could put extra cards and drive some things in. This is actually the connector for that. So this may have had one installed at some point. And that’s what this external cable was for, I believe. And, yeah, it’s got some bits of Velcro on the back, which is quite interesting. So obviously had something stuck to the back at some point in its life. Unfortunately, I don’t think we’re going to be able to find out what that was.

Very interesting. If we zoom in on this, I said this was an earlier- I thought this was an earlier revision. But just tucked away under here, I don’t know if you can see that, that’s an 8MHz 286. So it’s actually a faster machine than the previous one that we just looked at. And finally, of course, we have… It was in a 16-bit slot. Like I said, they are forwards and backwards compatible. And this is a serial and parallel card. I think this is the same card that I’ve got in my 5150 as well. So this is probably the card that should have been in that other machine as well. But as you can see, we’ve got a serial port and a parallel port for your mouse / modem and a printer.

So, some really interesting stuff there and actually in surprisingly good condition, there’s a lot of potential for some really cool future projects here. And if you do have any ideas or any suggestions on what I can do with these machines, do please let me know down in the comments, I’m always open to ideas. But I think that’s all I have for you for this video. Don’t forget to subscribe to the channel so you don’t miss out on those videos, which will be coming up at some point in the future, once I’ve worked out what I’m doing. And as always, a big thank you to my Patreon supporters, my Ko-fi supporters and my channel members whose names you see on screen as I speak. And as always, a big thank you to you for watching and I’ll hopefully see you next time.

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