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Good morning guys and welcome back to the ValorosoIT channel.
If you like retro computers and vintage electronics you are in the right place and, as I often suggest, activate the notification bell and subscribe to the channel! In fact, it's the opposite: subscribe to the channel and activate the notification bell!
What do we have back here? It's the Commodore 128D that I purchased a few days ago and I showed you in the unboxing video from a few days ago.
I bought it on eBay and the conditions were not the best. Now let's also see the purchase I made on eBay, but today we mainly see the test of this Commodore 128D. Do you think it works or not? Because the premises were not very good: 100% UNTESTED. However, generally, I buy things that are 100% tested and working, maybe even good looking, but then they arrive to me not working, like the Commodore Plus/4 from a few months ago, or completely destroyed like the Commodore SX64.
And, this time, when the computer is 100% UNTESTED, well… I'm optimistic!
Come on, let's see the order I placed on eBay and then let's continue with the test of this computer.
I found this listing on eBay. In Italy the prices are unacceptable, while abroad you can still find something at a decent price. In this case, the price was very high, because the seller was asking for 555 euros, plus 46 euros for shipping from Austria! But, in practice, I made an offer at about half the price and the seller accepted it. So, from this point of view, I'm quite happy.
The computer was in, well, not perfect condition, because the keyboard can already be seen to be yellowed. In addition to the Commodore 128D and the keyboard, there are also a series of accessories that have little to do with the Commodore 128. There are two power supplies for the Commodore 64 and a power supply for the external drive (which could be the 1581, for example). But we have already seen this in the unboxing video I made the other day. There was also this Commodore 1541 drive, which is particularly modified. In fact, you can see a couple of holes in front with buttons, holes... Let's say that I wasn't very interested in this drive. More than anything, I was interested in the Commodore 128D. The keyboard is German. Oh well... this disturbs me a little. But, on the other hand, a German keyboard is also fine. In the end, I need the computer to keep it in my collection, so it's not like I have to write who knows what texts about this Commodore 128D! The computer is in fair, not beautiful, condition. There is the Windows 95 sticker which, in fact, we had already seen in the short unboxing video. Unfortunately, one of these two cable clips broke: you will also see it later, when I show you how I got the Commodore. One of these two has fallen off. Here, various accessories, power supplies, the manual in German for the Commodore 128D. As for the advert, it certainly didn't promise well, because... it talks about a Commodore 500, when first you see C128D from the description and, also from the photos, you can see that it is a CBM 128D, with the keyboard and an external floppy disk drive, NOT TESTED, because it doesn't have the monitor to test it. So the computer is 100% untested.
So I say: if this is untested, will it work? Won't it work? Now let's find out. Until now, some things I bought as 100% tested and working, actually didn't work. Like other things, which looked very nice, they actually arrived broken because the packaging was not adequate. So, at this point, an advert like this starts off quite negative... with a computer with the wrong wording, untested and, in short, it can be seen that it has some small aesthetic problems...
Now, in fact, let's go and see it: will it work? Won't it work? In your opinion, is it okay or not? Now let's try it!
And here is the Commodore 128D that I received from my purchase on eBay. This little piece here is the one that unfortunately came off later. Now I'm trying to show you.
I don't see any particular problems reattaching it. I'll probably glue it down and also put some small loose metal pieces inside the plastic. If I can, I melt them a bit with the soldering iron then insert it first on one side and then the other into the piece of plastic, together. A little glue, and it should stay pretty sturdy.
The keyboard, with German keys, the plastic case with side handle. The keyboard can be housed in the lower part of the case, which has a special compartment.
To test the computer, I will use the usual diagnostic test (586220 diagnostic cartridge) of the Commodore 64, which I had already shown you in a video: the one in which I turned on the Commodore 64 after many years of inactivity and tested all the peripherals. It is also good for the Commodore 128, since it has the same ports, therefore: the cartridge port, where to insert the interface that allows the loading of all the tests; the tape; the external floppy disk drive port; BUS serial connector; the two controllers (therefore joystick or mouse) and the card for the User Port.
I don't use the tool to test the keyboard, because the Commodore 128D keyboard has a connector that connects to the outside of the computer. And then, in any case, I can test the keyboard by hand, typing on the various keys and seeing if everything works on the monitor. As long as the computer starts, of course!
Another tool that I use to test this computer is this converter, from the computer's RGBI port (because you know that the Commodore 128, as well as the Commodore 128D, has the possibility of connecting two monitors, one with 40 columns, the one that connects to the standard video output and one with 80 columns, which connects to the RGBI output).
I had made a video of this converter, so if you want, you can delve deeper into the topic. The converter requires external 5V power (for this I also have a power supply) and has a VGA output to connect it to monitors. But be careful, not all monitors are suitable: the monitor you use must support horizontal synchronization of 15 kHz, and this is not a given, because they generally support starting from 31 kHz. So, most likely, a monitor you have is no good. You need to find special monitors.
I will also use a floppy disk, to see if the computer's internal floppy disk drive is working properly.
Come on, let's be optimistic! The first thing I do now is turn the computer over and open it, because, before turning it on, as I showed in the video where I showed how to turn a computer back on after many years of inactivity, you need to test the power supply voltages of the power supply. In this case, unfortunately the power supply is internal, so you have to disassemble the computer and test voltages from inside. Instead, on computers like the Commodore 64, or even the regular 128, you can test voltages externally, because the power supply is located outside the computer.
Let's unscrew the four screws that keep the Commodore 128D closed.
There are also two rear ones.
We put them in a small bag, so there is no risk of losing them.
Or… I lose the bag and lose all four screws at the same time!
At this point, let's try to open the Commodore 128D container.
I open the side handle that seems to keep the two parts closed. I lift… oh yes, it's coming off.
You have to try to slide it towards the back, because there is a tab here that keeps it fixed, but, in reality, you have to slide it towards the back. The operation is a bit delicate.
This is the inside of the Commodore 128D! This is the power supply that connects, on one side, to this, which is the internal floppy disk drive controller board, and then there's another power supply cable that goes all the way up here. Back here. And this is where it connects to the motherboard. So I'm going to disconnect this connector and this one, so I can power the computer, test the voltages with the tester, but without keeping them connected to the motherboard, obviously. I test the voltages with the power supply disconnected from the rest, so that, if they are wrong, I don't run the risk of blowing anything up when I turn on the computer.
Here, let's disconnect the connector that goes on the motherboard.
Here it is.
And we also disconnect the power supply connector that goes to the floppy disk drive. And here it is.
Let's put the tester so that it measures the DC voltages and start connecting it here, then to the yellow wire and the blue wire, and see what voltage we find. Obviously we need to power the computer. You have to be careful because, since everything is open, there is the possibility of getting an electric shock! So, I do NOT urge you to do what I do! I connected the 230 volt AC power cord and the tester that measures the DC voltage reading. I turn on the computer's power supply.
And here we find approximately 11.5 V. In practice, this must be the floppy disk drive voltage, not the logic voltage. Now let's measure the other one too: 5.3 V: it's good.
So on the floppy disk drive the voltages are right.
Then, if you feel like it and, above all, if you have a tester that supports it, you could put MAX, so that the tester goes to measure the maximum voltage, you never know that, in some moments, the voltage increases, reduces, increases again and reaches values that are not optimal for the components. For example, now, if I turn off the power supply, the maximum has remained more or less constant.
Let's try turning it back on. Here, during the switching on and off phase, the maximum is modified for a moment, you see that we started from 5.3 V (and something) and now we are at 5.394 V, but they are still all absolutely normal values.
Now let's measure the voltages on the motherboard connector. I turn the tester off and on again, in order to remove the maximum measurement and try to connect to the motherboard connector, therefore to the red which should be 5 V. Yes, here too, 5.3V. I imagine, however, that the supply voltages here on the floppy and on the motherboard are obtained in parallel from the power supply, so, in short, I'm not surprised that they are exactly the same. Another measurement we can make is the alternating voltage, therefore between this wire and this one, obviously setting the tester to alternating.
In theory it should be 9 V AC, but it is very common to find a slightly higher voltage, like 11 V, on the power supplies of both the Commodore 128 and the C64. Okay... we'll make it work fine.
Well, at this point I can put the power supply connectors back on the various boards and let's see if the computer starts.
Come on, fingers crossed... To reconnect everything, I disconnected the 220V connector and also turned off the power supply, so I can reconnect the two connectors: the floppy one and the motherboard one.
Obviously, you need to be sure to connect them straight and not backwards, rather than with a pin offset from one side to the other. Because, at that point, it would really be painful.
Come on, I'm curious! Before connecting the various test circuits, I try to turn on the computer. Then I connect the keyboard and the video connector located on the back of the computer.
I reconnect the power to the computer which remains open for the moment, and turn on the monitor.
The monitor must be on audio/video input, so we put it on AV2, which is the input I use.
Now, let's turn on the computer. Is everything connected? Yes: keyboard is fine, monitor is fine, power supply is fine... For the moment we should be there. So, let's turn on the computer!
I go? Do you like the video? I go?
Come on! What happened???
No, look here, there's this 80 column button that's been pressed. Let's do the operation again.
Damn I have shivers now because it seems to work…. So I remove the 80 columns, put on the 40 column monitor. Ready? Come on…
Yes, he's gone!
Not tested... working! It's incredible stuff. That is, I buy them in working order and they don't work. I buy this untested and it works! Show!
Let's do some testing on the keyboard at this point.
It has strange keys, because it is a German keyboard. In fact, here is the Z and here is the Y: but that's right, then. Dunno... And why do you see Y here and Z here? Ah, maybe because there is this button. Look at how it does it: it changes and at this point, if I press here it makes Z, while if I return by pressing this button, if I press here it makes Y. What a special thing!
How beautiful are the sounds of these keys here! Do you remember the ASMR video I made?
I program in Basic... let's do some advertising on the site: www.valoroso.it
Space, semicolon, where is it? Here, no, eh... where could it be?
Ah, this, because, obviously you have to be careful about the character set you use.
20, go to 10 and… start! Well, I'd say it works!
Then, to improve the image quality for a moment, I had already shown, in another video I made, that it is possible to use the S-video output, always inside the 40-column video output connector of the computer. It's good for both Commodore 64, C128, Commodore 16. You can use the Svideo cable. In this case, I use a very normal composite video cable (CVBS), so there is some small defect on the monitor. But, in short, it's a well-known situation.
At this point, what do we do? We have two possibilities: either we test all the peripherals with the test circuit or, alternatively, we try to connect the other monitor? Well, I can't do a survey, directly online like this, also because the video is recorded! So, I decide! Let's connect the second monitor and see if it works. I use this converter, from the rear RGBI port of the C128 to VGA, as mentioned before, at 15 kHz. External 5 V power supply.
Obviously, to do all these operations, the computer must be turned off.
There is a dangerous proximity between the converter and the 220 volts... But here we have to do these high-risk jobs! High risk on the ValorosoIT channel! Let's try not to let the 5V wires touch each other. Even if they are only 5V, I would hate to blow everything up. We also turn on the second monitor. We turn on the external 5V power supply.
The second monitor must not be set to audio video, but must be set to RGB-DTV input, which is then the input that supports 15 kHz: the VGA port.
Shall we turn it on? Ready? Yes! Works! The 80 column output also works!
So in this case, both monitor outputs work! The keyboard works, all we have to do is try floppy. We insert the diskette we saw before.
Directory command… No. I'd say it's not working.
The sound is different than before, however. It always gives the error: 'file not found error'.
So I would say the floppy doesn't work.
Alright, we'll get over it! After all, it was thought that the whole computer might not work, but instead it works! Oh well, the fact that the floppy doesn't work, nothing happens.
Alright, come on! I disconnect the second monitor, then go back to the 40 column monitor, removing the RGBI to VGA adapter and connect the entire test circuit, made up of the various red cards that I had shown before. Obviously all cable connections and disconnection must be done with the computer strictly turned off, so as not to risk causing short circuits or voltage transients on the various lines.
Okay, now: controllers. Then, we disconnect the connector of the internal floppy disk drive, because I wouldn't want it to give false signals, rather than who knows what else, when I then connect this connector of the external floppy disk drive
From the rear you can clearly see the small piece that fell off during transport.
Then I connect the interface that connects to the expansion port, with the test program. This is diagnostic test version 586220.
Connector for the external drive, also for the printer, however the IEC BUS.
Then, door for the tape.
And finally, User Port, on this side. It says hold upwards here.
Ok, everything connected, we can turn it on at this point!
Ready? Go!
This is the classic diagnostics screen of the Commodore 64 version 586220, which is also good for the Commodore 128, at least to test the main things. So, we have the memory test, the video memory test, the RAM test and then we will also test the SID, then the sound part. All these things are common to the Commodore 64 and the Commodore 128, and therefore also to the Commodore 128D that I'm testing now.
So, there is some small error.
I brought the microphone closer to let you hear what you hear when the audio test starts.
Virtually everything works, except for the userport.
Now it says 'ok', so it could also be an occasional error.
And, in any case, it would be a matter of replacing one of the two CIAs or, alternatively, to see if there is any broken track on the printed circuit, which does not connect the userport well with integrated circuits internal to the motherboard.
Anyway, everything's fine, come on! Apart from the internal floppy disk drive and the user port, everything else seems to work, including the dual monitors.
Well, I can consider myself quite satisfied with the purchase. Practically everything works, with the exception of the internal floppy disk drive and the user port, which could be the user port or some integrated device that drives it. Then, later, I will delve deeper into these things in the future.
Would you be satisfied with such a purchase, bought as untested and finding it in these conditions, still working, I think a good 80%?
Well I'm quite satisfied, also given previous experiences, in which I bought working things, which then weren't working. Here, I remind you to subscribe to the channel and activate the notification bell. If you like it, give the video a like… and… see you next time! HI!