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A resistance of 16 ohms across +5V and GND on the logic board is normal. For example, here's another situation where a IIfx had similar results, and I have seen similar results on my IIci as well: https://68kmla.org/bb/index.php?threads/jmacz-mac-iifx-project.45083/page-4#post-508648

Haha, believe me, I probably won't be doing much more than Blinky with mine. So many projects, not enough time! Happy to help, and glad you got it figured out!

Hmm...did you make sure to export PICO_SDK_PATH after you changed it? Your ls command shows you have it set correctly in your current shell, but maybe the exported version is still the old version. Just an idea anyway. I just redid the setup steps from scratch on Ubuntu and it worked for me (all...

That error message is saying that PICO_SDK_PATH is not pointing to your checkout of the "pico-sdk" project from GitHub. So wherever you checked that out, that's what they are saying you should define PICO_SDK_PATH to be pointing at it. I see what you mean about how that section of the docs is...

I don't know how to let things go! Even though I'm probably fine on /WE rising edge hold time with my hardware since the ATF22V10 is so fast, I was curious about what I could have done to fix it if the timings really had mattered there. So I tried sticking with using /DS for the falling /WE...

Nice! Thanks, that's very helpful! I will definitely take a look when I have a chance. I love this idea too! Realistically I'm not sure when I'll have time to play around with it, but I suppose for starters I could just wire up a couple of ports to a header. I'm guessing having the port shield...

Gamba had startup circuit schematics for the IIcx and IIci. They look almost exactly the same: https://vintageapple.org/gamba2/schematics.html

I bet you won't have any trouble! I'm very new to this stuff so I think that's the main reason I keep running into snags. Definitely! I'm already sick of pulling the chip and putting it in a programmer over and over again. I even read that another option is you can use Intel/Altera's Quartus...

I'm not sure if this explains any of the other issues I ran into earlier, but today after I threw together a simple LC PDS card with a few LEDs on it that I can control through the Mac's slot E address space, I came to the realization that with the LC PDS slot, I definitely always have to...

The /CS pin on the flash chips is just tied to ground, so I shouldn't be hitting any problems there. Thanks for the idea though! The only other thing that comes to mind is these N28F020 chips I got were from China (AliExpress and Utsource) so who knows about their quality. They appeared to be...

If I'm being honest, I still don't understand why my earlier idea using only /AS didn't work with Intel flash chips and it kind of bugs me. I'll probably just let it go so I don't drive myself crazy, but this whole thing seems weird to me. The CUPL for doing it based on /AS was a lot more...

Thanks, that's good to know!

Thanks for your ideas! That's a good point. @halkyardo also suggested I should probably be triggering off of /DS for the writes. (And I guess triggering off of /DS for reads would be the same as triggering off /AS, so either way should be fine there). Yep, just a single register does the trick...

I thought about it more and came up with this idea, basically delaying /AS through a few cascaded registers so that I can generate a delayed /DSACK to force a wait state, and also decide exactly when to do a /WE rising edge: This seems like it meets all the timing requirements. But when I try...

I've been tinkering with trying to recreate an LC PDS card that I'm pretty sure existed inside of Apple at some point: a ROM Flash SIMM programmer supported by Apple's Flasher app, at least for the Quadra 605 and LC 475. I wrote a blog post about it a while back where I described getting it...

So cool! Ahh, you're right. I probably wouldn't be adding any new info. I knew that...I just wasn't thinking! I haven't paid close attention to how that opening works, but the next time I have the card out I'll think about it a bit. This sounds kind of crazy, but I guess someone could make a...

Yay! Excellent job! What a fun use for ChatGPT. I wonder how similar that circuit is on the G3 Blue and White. I have a couple of those motherboards laying around and might be able to check. I think you're onto something! That all checks out -- it never occurred to me that if you start from...

Very, very cool! It'll be fun to hear how the testing goes with the keyboard power on. Ahh, I didn't factor that into it. Very good point. I also haven't had any luck finding anything even close. It's interesting that the footprint on the PCB has two square pads (usually used for denoting pin...

I've been silently following this thread ever since the beginning and very much enjoyed it! Really nice work! I somehow just today discovered that for the past decade, I've had a Beige G3 Desktop that came from the factory with a DVD drive, and indeed it has a Bordeaux card inside. With the...

That was a fantastic explanation @Melkhior! Thanks for sharing it. I learned a few things reading it too.