This is the video transcript. Read the original article with all the details →
Good morning and welcome back to the ValorosoIT channel, the channel dedicated to vintage computers and electronics. Today we're talking about this IBM PS/2 model 30 computer with an Intel 80286 processor. I had already shown you, in the past, in other videos, another computer from my collection, still an IBM PS/2 model 30, but with an Intel 8086 processor. With that computer, I had carried out a series of experiments: I had installed the Intel 8087 mathematical coprocessor, I had replaced the Intel 8086 processor with an NEC V30, to see if it worked, and moreover - but I will still have to carry out this experiment - to see if with that processor (NEC V30) it is possible to use apps that are not normally used with the Intel 8086.
Regarding this computer, therefore the model with Intel 286 processor, I purchased it on Wallapop. You saw the unboxing in a short video I sent you. From the same Spanish seller, I had purchased two computers: this one in working order and another, also model 30-286, which however was supposed to be for spare parts only. Here, luckily this computer arrived to me, with a little damage... That is: luckily it arrived to me, unfortunately with a little damage to the bodywork, at the back of the case. It's not very noticeable, fortunately. But the other computer, which I had purchased for spare parts, never arrived. Eh, unfortunately it must have been lost. Who knows where he is right now. Obviously I was refunded but the disappointment remains for this computer which unfortunately did not arrive.
I then ordered another model 30-286 computer for spares. In the sense that it didn't work when it arrived, I managed to recover the hard disk, the floppy disk reader and the motherboard probably works too, because the only thing that in my opinion is broken is the power supply. I also tested the RAM and, indeed, they work, so I'm really convinced that it is the power supply of that computer that is not working. It's better this way: I have a few more spare parts for this computer, you never know if something might break.
Other experiments that I am doing with this computer, but also with the model 30 with the 8086 processor, is to transfer files from these computers to more modern computers for example with Windows 10 via the FastLynx program and a serial cable. The data transmission is automatic, so it goes on by itself. The only thing is a little slow, because you know, as a serial port more than 10KB per second is difficult to do. But it is also true that, on these computers, the hard drives are not that big. We're talking 25MB, 30MB, 60MB of data. Even at a slow speed, they somehow go smoothly without needing to go back and forth with floppy disks, copying to floppy and then copying back to the computer. Also because modern computers rarely have a floppy disk drive inside, so it is more convenient to transfer via serial, even via USB to serial adapter. So, everything is compatible even with modern computers. However, I will make another video about this, I don't know if a short video or a full video.
Well, let's proceed with the topic of today's video which is the replacement of the real time clock of this computer, therefore of the IBM PS/2 model 30 with 286 processor. Real time clock which is the Dallas DS 1287, which is the same one that is also found inside the IBM PS/1, again with 286 processor. So this clock obviously contains, inside, the system clock but also 64 bytes of RAM, which are for the configuration system, as well as watch usage logs. There are several alternatives to replace the DS1287 real time clock. I went towards this one, which is basically a modern alternative for these chips. Then you know that I am very interested in the originality of computers, so the first attempt I made was to purchase an original DS1287 from Aliexpress.
Unfortunately it never reached me. That's how it went. Who knows where the package is. That too got lost in the meanders of who knows what truck, and they never reached me. The second alternative that many consider is, for example, to modify the DS 1287. I know that you can mess around with the drill and take out the battery wires and put in an external battery. This is also a viable operation, however, in the end, also due to the cost which is very low, I oriented myself towards this chip here: it's called nwX287, which in practice is a modern alternative to those chips. Well, it would be nice to also put a nice little black box like the original Dallas DS1287 chip around it, perhaps printed with a 3D printer. I don't have it at the moment, so I'm happy with the chip as it is. It being understood that, perhaps, sooner or later, I will try to order these chips from AliExpress again and see if they arrive. The risk, I hear many people talking about it on the internet, is that the DS1287 chip will arrive from China, but that too will have a dead battery inside. Because in short, after a certain number of years, 10 to be precise, on the datasheet it says that it is guaranteed for 10 years. Well, after this period, the battery tends to run down and therefore the system configuration memory no longer works and the clock no longer works.
First, let's try to turn on this computer, so we also hear the beautiful startup sound. Let's see the problem caused by turning on the DS 1287 with a flat battery, therefore not working. We try to load the diagnostic disk and there too we see that it gives an unpleasant error. I know that on some computers, when the DS 1287 battery fails, the floppy disk drive may also fail. In this case, however, I'm lucky, the floppy disk drive works, so the diagnostic programs load, but they immediately give an error. Now we see it. After that, let's try to replace it with this chip (nwX287) and then check whether it works or not. The computer appears already open, because I have already removed the upper part of the case. First I turn on the monitor and then the computer, you rightly pointed this out to me, because sometimes I happen to do the opposite, turn on the computer first and then the monitor. But the correct sequence, in fact, is: first the monitor and then the computer, which turns on when the mains voltage is stabilized, pass me the term stabilized. In the sense that there are no more voltage spikes for turning on printers, monitors, etc. We also insert the original disk inside, the IBM starter disk.
[ASMR]
The two beeps are the error (161 and 163).
Here, you heard the two error beeps (161 and 163) first. Normally, if there is no starter disk inside, the computer freezes and asks you to press the F1 key. Only after pressing the F1 key does the boot start from the hard disk or floppy disk. In this case, since IBM's own starter disk is inside, you see the beautiful logo placed like this, drawn in characters, a spectacle, the computer started directly with the original chip, we said, the original DS 1287 Real Time Clock, the broken one because it had a flat battery. Let's see what happens.
Here, he immediately notices that there is a problem with the non-volatile memory (00161), says that he wants to configure it automatically and then restart the system.
Eh, there is still the error, in fact. Now reload the starter disk and, unfortunately, we still end up with the same error (00161). At this point, I would say to try replacing the Real Time Clock with the new one (nwX287). Furthermore, I saw that this new one wasn't delivered to me with the battery. So I had to buy the battery separately. Let's mount the battery on the new Real Time Clock, install it inside the computer and see if we can remove this error. Among other things, the battery needed is a CR1220, I couldn't find it at the supermarket, I had to go to an electronics store specifically to get it immediately, otherwise I could order it online. It's a shame that it wasn't supplied directly with the Real Time Clock, replacing the original one. Ah, damn, these batteries here. Oh, I did it, let's go put it in the appropriate slot.
Okay, good. Now I turn off the computer, I turn off the monitor, obviously I turn off everything, let's try to remove the old Dallas and insert the new one following the correct orientation. Here, the sequence for turning off the computer is the exact opposite of that for turning it on, that is, first the computer is turned off and then the monitor, to prevent voltage spikes from entering the computer by turning off the monitor. Inside, the computer looks like this. For those who aren't exactly experts, let's see here: the floppy disk drive, the hard disk, the riser card with all the 16-bit ISA slots. Down here we have the RAM, the power supply, and we have our Real Time Clock here. The Intel 286 microprocessor is very nice. Luckily, in my opinion IBM was quite foresighted in this, the Dallas DS1287 is mounted on a socket, so we don't need to desolder anything, we will simply pry it with a screwdriver, and then insert the new nwX287 chip. Wow, already done!
So, let's see what the pinout looks like. Ok, I would say that it should definitely be put in this sense, you see there are some missing pins that give the indications of where it should be inserted. The chip was placed in this direction here, with pin one facing here. And so will we. Even if he calls it little foot three here, probably, here he says three. Oh well, in any case, this is the orientation.
So I have to say that I'm not 100% satisfied with the assembly, they could have used shorter PIN strips, these ones below, so as to ensure that they didn't protrude from the socket. But now let's try how it actually works.
Ready? So, exploding... no, it's not exploding, luckily! The IBM diskette is always inside.
It always gives the same errors (161 and 163). Let's see if we can solve it with diagnostics.
Restart... Come on, we'll do it! Come on… Yes, it didn't give any errors!
No!!! What is this 163?
Now let's see... but 161 has disappeared, we are already one step ahead. Maybe it's just the time that isn't set. Well, well, date and time not set. Let's try to set the time. There is also the possibility to set the configuration. But I would like to set the date and time. Here it is: date and time. No, well, let's say 1987 was a few years ago, eh? Today I'm recording is 8/12/2023. Among other things, I have doubts... but does he know that it's the months before and the years after? Let's see right away. Let's pretend it's the 30th. 30th, here 30th. Ah, damn, take it all. How do we know which one it is? First the month and then the year? Because, you know that Americans perhaps put the month first and then the day. Alright, let's try. 12 = December, 08, 2023. But I also have to set the time. I don't know if it takes August 12th or December 8th. We'll find out later.
Instead, regarding the time, I now see that it is 11:05. So, in theory, we have everything set up now. Let's see the configuration, but just out of curiosity, let's see what's inside. Let's see the configuration... Ah, it's about the memory, the type of diskette. This is why sometimes, probably, the diskette is not recognized if the non-volatile memory inside the clock does not work, because it is indicated here in the configuration. The possibility of installing a mathematical coprocessor, which I also ordered on AliExpress. When and if I get it, we will make the video, probably a short video. Hard disk installed, good. We can change the configuration, but I don't see the need. Make a backup, a restore of the configuration, and that's it. All right, come on, let's try to boot and, at this point, start the computer with its hard disk. So I turn off, we said first the computer and then the monitor. I remove the IBM diskette, which isn't exactly original. I showed you in another video how to write diskettes: you download them from the internet and use the DiskWrite utility with a computer, obviously, that has a floppy disk drive and an internet connection, to save them on a diskette. Now let's try booting from the hard disk again at this point. First I turn on the monitor. Now I bring the microphone closer to the computer. We turn on the computer, so we can also hear the hard disk spinning while it starts up.
[ASMR]
Yes, just one beep! Eh, the computer started up, luckily, so we solved the problem. It was exclusively this chip. Now I'll enlarge it for you, Dallas DS 1287, it says Real Time under it, precisely, because it contains the system clock and then a little bit of RAM for the configuration. Just very few bytes: 64. I saw that there is the model after the DS12887 which has 128 bytes of RAM. The computer is in Spanish, because, as I told you, I purchased it on Wallapop from Spain. I haven't done much work on this computer, so I haven't reformatted it yet, I haven't put anything in it, it's just the contents of whoever sold it to me. In particular, apart from a few games, there is Windows 3.1, which I had already started, but it is Spanish and also does not have the mouse driver. But… it's okay, just to start it. Let's see if it works. As kids today would say, the computer is trying hard to load Windows. That is, he's struggling to load it, he's working hard. No, because we also need to do linguistic updates, eh, otherwise we no longer understand our children when they speak.
Here it is. Well, without a mouse it's a bit inconvenient to walk around. So he should have gotten the right date here, actually. Because it says 8/12, being from Spain, it will have a date format compatible with our Italian, therefore 8 December. So we were right, first, to put it the other way around, that is, first the month and then the day. Solitaire, how long has it been since I played it. Alright, come on, let's try closing: Alt+F4. No, the system does not close. Yes, come on, Alt+F4 always closed everything. Let's see, huh. Yes, yes, yes, yes. Data: we find it. Day 8, month 12, year 2023 and the time: 11:12. Because, in the meantime, the recording continued and a little bit of time has passed compared to before. Well, I'm happy to have solved this problem too.
Then I'll install another one of these chips on the IBM PS/1. In fact, this computer also needs a little attention. IBM PS/1, still Intel 80286 processor, also inside the Dallas DS 1287 chip to be replaced. Furthermore, I wanted to update it by inserting this original serial module. I managed to find it, to have the serial port, then mount a modem, connect it to the Internet. I wanted to replace his hard disk because his has some bad sectors and, moreover, they had given me a color monitor for this computer. Because this monitor is black and white, monochrome. Even there, I say, that is, we are still talking about the end of the 80s, the beginning of the 90s. The monitors were in color. I mean, who goes to buy a computer with 286 monochrome? That is, it wasn't a computer that had to be born in black and white, they could have already had a color monitor... and no, it got this one in black and white. They gave me a color monitor, but, as I showed you in a short video, as soon as I plugged it in, it immediately decided to smoke a bit. So we found the new Pope, white smoke. I don't think it's anything serious, it's probably just the capacitor, the famous RIFA, therefore the filter capacitor that is placed at the input of the supply voltage, which has temporarily blown while awaiting replacement. But I still don't have time to get behind it, but this computer will also come out very well. I hope you also liked this video, that you found the indication of how to replace this component (DS1287) which very often gets damaged (because the battery runs out) inside these computers with Intel 286 processor useful. If you haven't already done so, subscribe to the channel so you will be notified when I publish new videos related to computers, experiments, reviews, unboxings, or short videos.
I'm not only on YouTube, I'm also on other social networks, on Facebook, on Instagram, on TikTok. So, if you want, you can find me there too. Until the next video, bye!