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Probably, but only Centris 650 have LC040 IIRC - Quadra 650 and 800 have full '040. I'm trying to understand the signal termination requirements of the MC68040, and it seems Apple has done it all: I can't see any termination for A/D on the Q900 schematics, it's present but labelled "for 40 MHz...

Would you have similar pictures of the back of (one of the) board(s)? I'm checking which termination packs of resistor related to the '040 are connected, and how the output buffer are set up (resistor R17{5,6,7} and R22{1,2,3}). I do have Wombats but installed in cases will all the trimmings, if...

Diamond has a free yearly license for some chips (which is not as good as ISE / Vivado, which have free-for-life licenses for some chips), but it seems the 5-V tolerant ispMACH 4000V/Z chips use another (older?) software package, ispLEVER Classic. That used to have free yearly licenses, but no...

No, they use completely different fabs. Anything new from AMD is top-of-the line, so single-digit nanometers (MI300 is using TSMC's 5nm for instance). XC9500XL are made on a 0.35um, or 350nm, process, and I think Spartan 3 are similar. That's the kind that was used for the Pentium MMX... The...

OK thanks make sense, such a complex board with just two layers seemed unlikely. The inner-for-ground-and-power setup is fairly standard, I should have guessed. So no margin for adjustment from that (6 layers is just too freaking expensive at JLCPCB, at least for now).

I've had success with the 74CB3T family, they're used in nearly all the *FPGA (NuBus needs stronger driver so uses direction-controlled level shifters, which work well but have much longer delays than the pass-through CB3T, fine for 10 MHz but might become a problem at 33+MHz). They are not true...

Dumb question - are IIci boards only 2 layers? I can only see two colors (red/green) for traces in your original picture. That would explain the quite complex routing I see on your beautiful purple boards!

i doubt they care :-( Hobbyist are a tiny fraction of the market for ICs. Keeping old chips around may have been worth it for an independent Xilinx before the supply chains disruption from Covid, but for AMD they might be more trouble than they're worth - and now they've gotten the axe. I'm...

For those designing for 5V hardware... XC95*XL are gone. Along with Spartan II and Spartan 3, plus more. https://docs.xilinx.com/v/u/en-US/XCN23009 Darn.

Or not. Darn. (the entire range is discontinued, along with more stuff like Spartan 3).

Unique for Macintoshes, and not that common elsewhere. The 68851 was late and complex and slow and expensive, and a lot of people used other solutions, mostly custom-made MMU. For instance, Sun for the sun3 range (but sun3x were 68030), HP with some of the 300 series (at least. 9000/330 and...

Another awesome piece of work :-) Pure tracing, or is there some associated schematics? Been working on those, but it's not moving very fast... I have a bombed IIci that could use one of those replacement board, if someone could do the transplant in Europe for me (I suck at soldering anything...

I don't know why I feel happy about it, but for some reason Renesas still manufacture some variant of their "QSpan II" Processor-to-PCI Bus Bridge, which has native support for the 68040 bus. They are bit pricey though. Theoretically, one could build a PDS'040 <-> PCI bridge board to be able to...

There's only 6 visible 71256, which suggest to me the two hidden by labels are also 71256, distributed identically to the Flash on he other side. Random guess: SRAM storage of the code for warm reboot, flash storage for more lasting attempts? With just a buffer and some SRAM you can't do a lot...

Technically, the bitstream can be generated for other resolutions to match the display (1920x1080 is the maximum the FPGA can handle and so common on cheap HDMI LCDs it's a good default), but that resolution becomes the 'upper bound' and all lower resolutions are as you described window-boxed...

The carrier board itself was completely assembled by JLCPCB, other than the through-holes connectors (two 2x32 2,54mm pitch header, and the 140-pins KEL connector). Then you manually solder the 268 TH pins, that's the only manual step. @Jockelill had an extra step as in the first batch, there a...

One comment: you've dropped the mac ABi (passing values through registers) in favor of C (stack), but the '030 needs all the help it can get performance-wise. Once the code is stable, I'd suggest reinstating a register-based ABI wherever possible to save a bit on time, at least for function on...

For my *FPGA I picked CC BY-NC-SA 4.0 for the hardware (SW is straight GPL). The non-commercial part is not so much to avoid third-party making and selling the design, but as a safety net against being asked to support subpar copies sold by third-parties. If someone wanted to make and sell them...

Hardware-wise, there's no major problem. Just need some memory chips and an adequate memory controller mapped in the proper area, and some way to discriminate between the two maps so the new controller doesn't conflict with the onboard BBU, which is likely the most complex part. Software is the...

To simplify your life, rather than MacsBug, you can build a Mac console application that will do e.g. printf("0x%08x\n", *(int*)0xFE000000);. You can do that natively with CodeWarrior, or from a modern box with Retro68. Unlike modern operating system, this area is not protected from user access...