forum.defence-force.org

... wire a DPDT switch to a decent 2A 5V PSU and bypass/remove the regulator altogether and simply wire the switched 0v/5v lines to both the Pi and Oric - any thoughts on if this presents any concerns? That's a better approach, IMO, once you are on the "inside" of the regulator, supplying...

I see, thanks for the link/context The above diode suggestion by @iss will solve the problem (make sure it's in line with only the 65C22 leg, as per my caution on physical layout issues) -- the 65C22 having "totem pole" output means it will try and drive the line both HIGH (when idle) and ...

The pull up resistor also connects to the 6502 IRQ input, and any external peripherals. Removing it may well have unintended effects. What is the source of this knowledge that the resistor should be removed? The only other thing to check is the physical order/routing of the track, you may find that ...

Voyageur wrote: ↑Sun May 26, 2019 12:04 am There is not much room inside the case of the Oric.

I didn't address this most obvious point It would take some serious crowbarring to get it in.

I do think the suggestion for building it into an Oric/Atmos case (minus the original motherboard) is the best idea.

Can I/Should I pull 5V for the Pi directly from the Oric's regulator I would say no -- a fully working PI may peak higher than that 140ma, and then you've got your USB peripherals etc. which need power. If the power sags, the PI will start to misbehave, if you're lucky you'll get a "rainbow pa...

Here is the matrix and the keys are on the same row: They're not in the same row, hence my puzzled comment. Original posting 7 failed keys: Right: "8 0 - =" and Left: " , . / " By your picture (which is in a different (more logical order) compared to the service manual) :- "...

An odd combination of characters, they seem to be grouped physically (by proximity) rather than by organization in the row-column matrix (see the Service Manual .pdf).

Wait, you got a 10 key? What advanced model of Oric is this?

although the left and right shift keys do not work on all keys I can get by using alternate shift keys to cover the entire keyboard. That is a pretty odd symptom. The shift keys (and FUNC, CTRL) are on a common "column" of the keyboard matrix, with nothing else. So are you seeing any prob...

After powering it up (at the wall, and plugging in), if you get nothing beyond the black-white bars, try briefly shorting pin 40 of the CPU (Reset) to any ground point (e.g. Pin 1 or 21 of the original CPU or pin 1 of 6522 -- I don't know the significance of the pin-1-cutting comment you posted, but...

And there's Oric Owner, Issue 05 (Page 44-45, centre pages), which is quite readable.

http://www.defence-force.org/computing/ ... ner_05.pdf

... buy four Orics, which was not especially cheap, as well as design and print PCBs manually because there were no PCB design tools available on the Oric. Oh yes, at about £149-£169 (and those are 1980's pounds, not the current ones!) it would be a bit crazy, financially. However, PCB design tools...

Nobody knew how to lock-step 4 ULAs in the 1980s, or if they did, they were keeping very quiet about it

Looking at the 65c02 i think it was fitted later as the date code is 8813 so it's not factory fitted. Your board seems to be date coded 83 44 (on the back), the ULA is 83 12, but the DRAM chips (only 2 of them? 4464 x 2?) are from 1985 (8527). That's not a board configuration I've seen in real life...

A trademark is something you buy the rights to. That company asserts that it owns the trademark so this means they bought the rights to it from the proper government office It's something you *can* buy the rights to. It's also something you can assert "Hey, I just invented this brand/logo!&quo...

Symoon wrote: ↑Wed May 01, 2019 6:03 pm I'm afraid he's far too busy with real life right now.

I don't know what exactly this means, and it's none of my business, so don't feel the need to explain.

However, "busy with real life" won't be a valid reason for ignoring a take-down attempt by lawyers. That was my concern.