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Since I got my Oric to work, I have now tried it with my Microdrive and it seems to work!
Happy, happy
I get a screen that says: insert system disc
How can I get hold of a system disc? I got some empty discs which I bought for my Amstrad PCW8256.

rst IS stable, I just made an error with my oscilloscope. The data pins seems alright, but A0-A7 constant high and A8-A15 constant low.

You're using RND(1), that is, RND with a seed of 1. It should always generate the same sequence of numbers. What you need is a way of getting a random number to replace the 1. Just make a loop which increases a variable and at the same time waits for the user to press a key. Then use that variable i...

The clock seems fine, but rst is not stable. I've replaced C21.

I have replaced the RAM-chips, but the computer still doesn't work. The address lines A0-A7 is stuck high, so it probably the processor or perhaps IC8/IC20 (74LS257).

the crap you see before the prompt is just random data in ram. Ah, ok, maybe it's because the RAM-chips are of different types, since I replaced some. what's wrong with the last one? Well, I have just had time to check with my oscilloscope and found two RAM-chips that seems to be broken (no activit...

Yay, one Oric repaired! 7 of 8 RAM chips were in sockets, the one not in a socket was broken. The picture quality is a little worse than the other ones, but I'm only using RF for now. One other thing is that the other orics have black and white stripes at boot, but this one has a little green and ra...

It wasn't the cap, because I don't have the original PSU for the Oric. But you gave me the right idea, because it was indeed my PSUs fault. It got a forth Oric now which works fine, and I got another PSU with it, so then I found out that the one I borrowed was also working. Still got two faulty ones...

Can you connect a ROM on the expansionport somehow? Many other computers used games on cartridges, did Oric ever have those?
The Microdisc ROM works like this in a way, doesn't it?

I got two orics and neither works. I have borrowed a third one which kinda works, this one is getting a picture but it's not really stable. I've measured the supply voltage with an oscilloscope and I can see that there's a ripple in the 5V with a frequency of about 100 Hz. This corresponds to the tw...

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Hm, come to think of it, I've got a ATA/SATA to USB interface which comes with a nice PSU with 12V/5V molex connector, I think I'm going to use that one.

Ah, that's a DIN? Not used to 4-pole DINs and they're usually female connectors on the computers, this one is a male.

Well, since it's probably impossible to find a connector that fits, I think I'll remove the plate in the back and just put in a new one with two connectors for 12 and 5 volts and just use external PSUs for both.

Yeah, I have opened it. One pin of the connector is connected to a 7812 and one to a LM323K and then one ground. So I guess it needs minimum 2 volts more, meaning 14V for the 7812 and 7V for the LM323K.