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Good morning and welcome back to the ValorosoIT channel, the channel dedicated to retro computers and vintage electronics. If you like this topic, you can subscribe and activate the notification bell.
What do we have back here? So, this was a somewhat special purchase. I got to know a person who approached me through the website. He filled out the contact form and told me he had two computers for sale: specifically, a Commodore Plus/4 and a Sinclair ZX81. His name is Ivan, he is a very kind person and he left them to me at a very interesting price.
At this point, I decided to buy them, even though they have not been tested and may not work. The seller was very honest about this and said he had no way to test them, but for the price he left them for me, I decided to buy them. Also because, if it were just for the replacement of the keyboard or some integrated circuit on the motherboard, it would still have been a bargain.
I want to thank Ivan for the package he sent me at a very interesting price. Now, I want to open the package and do the unboxing. Next, I want to try these two computers: the Commodore Plus/4 and the ZX81. Let's see if they work. The package seems to be packaged very well, it is nice and solid and of the right size to contain both computers. Let's see if the inside is really packaged as well as it seems.
We have some paper for packaging here. Let's start by looking at the first package, the Sinclair ZX81. Here's this other box, and then there's the original Commodore styrofoam.
Let's put it backwards. Come on, it's better. Here is the beautiful Commodore Plus/4 with its power supply which has the square connector. This here is also the warranty certificate, so if it doesn't work, I can send it back to Ivan. Let's see the ZX-81. Ah, here it is. It opens from the other side. I don't want to crush too much because I don't want to mess it up with scissors and the computer if it's nearby. Maybe there is too little cardboard thickness. No, instead, here it is. There is also a sticker. Well, I guess we can now try connecting them to the TV and see if they work. I always say this before turning on a vintage computer: after many years of being turned off, you need to test the power supply voltages of the power supply. I've made several videos about it. I'll give you the link to one of these videos so that you too, before turning on the computer, can test the power supply voltages. So, regarding this power supply, I, fortunately, already have mine, so I will not use the seller's power supply. But know that to test it, obviously, you need a digital multimeter to test the supply voltages, then connect it to the various pins to actually understand what the voltage is of 5 volts, 9 volts in alternating current, rather than 12 volts. It depends on the computer. Each computer has its own, but in this case I use a power supply that I have already tested and that works, because it is the one from my Commodore Plus4 that I already have in my collection. So, we can just go and connect video, power, turn on and see if this computer starts.
Ah I remind you, it is not tested. And so, even if it doesn't work, that's okay too. Obviously I hope it works, though. The video connector is on this side, and behind us we have the power connector. We turn on the voltage, I turned on the TV and put it on the audio video input. Let's turn on the computer. Let's try changing the audio video input, we put it on audio video 2. I never remember which is the SCART input and which is the composite video input, let's try. And no, unfortunately, from a black screen. Eh, as I expected, he will definitely have some of those three chips missing. So now the CPU or the TED or the PLA, which were the ones I had to change on my other Commodore Plus4. Nothing. This computer is for parts only. I don't know if I will repair it, because I already have a Commodore Plus/4 one in this case. I don't know if I will repair it also because consider that these three replacement chips that normally break on this type of computer already cost more than 100 euros just these three chips. So it's not necessarily worth repairing. But in short, always one more computer than in the collection. Let's do the test again, just in case. No, nothing, he's really dead.
So, let's now try the Sinclair ZX 81. Since the ZX81 that was sold to me by Ivan did not have a power supply, so I use my own power supply that I already have and with which I have already powered my ZX81, so I know that it works very well. So, television is not on audio video. But, in this case, it's on analog channel 36. We connect the antenna, we give it power. Fingers crossed. So, this seems to work. It's very difficult to see, probably because the TV is tuned badly, but you can see the cursor below. Before continuing, I'll try to tune the TV better. Another thing I can do is try changing the video cable, then the RF antenna cable, because maybe this one is a bit unlucky too. Eh, let's see if I can find another one. The best I've managed to get is a slightly shaky image, but let's see if I can write, at least, my name: 'Print', because there's the 'P' in 'Print' in quotes just because we're talking about Basic. Oh, damn! I don't know how to use this right here. So, let's give 'New line' and do first then 'P' of 'Print' + shift + quotes + 'AMEDEO' + quotes, because it puts four quotes. Let's see if there is any water. There is another quote. How many quotes! I don't know how to use the ZX 81, so that's why we come, let's turn it back on. I don't even know how to delete the line.
Print 'AMEDEO' is gone. So, the computer works, you can't see very well, but I don't rule out it could be the television. Of the purchase I made, I have the Commodore Plus/4 which doesn't work and the Sinclair ZX81 which works, even if I can't tune it very well to the TV. But, as I was saying, it could also be the television, we know that old computers and new televisions sometimes don't work perfectly. Furthermore, this television is not my usual one that I use to do experiments with the retrocomputer, the one I have at home is in my laboratory. Instead, I have this one in the office, but I'm looking for another one to have the possibility of turning on vintage computers here too.
Thank you for being here with me to try these two computers, do an unboxing and see if they worked. If you liked the video and it was useful to you in some way, you can like it, subscribe to the channel and activate the notification bell.
So for those who get to the end of the video to see it all the way through, I tried the Commodore Plus/4 power supply that was sold to me by Ivan. I tried it with the tester first and it works perfectly, so much so that I was able to connect it with my Commodore Plus4, not the seller's, and it turns on. So, the power supply works, but the computer doesn't. Instead, the ZX81 works.
Ciao!