Search results

There's OpenFPGA ongoing, and they do have some integration for Skywater. The mention of the Synopsys IC Compiler II pretty much kills the idea any hobbyist wanting to have a good look at SOFA (the license costs more than a decent house, and that's yearly; licenses costs are one of - if not the...

It's annoying, isn't it? Had that happen with the MC68060 pinouts I found on the web... and then promptly made the exact same mistake creating a footprint for the MC88110! Grrrr. Can't you just the same trick and connect the /CS output of the CPLD to an input pin of the same and use that to add...

Welcome! Congratulations, it's a very nice machine and it looks to be in excellent shape. The Wombat-based systems (so Q800, Q640, C650) are also in my opinion the best 68kMac you can get. I'm going to be a pedant (and show off my newfound knowledge), and say nope. At least two companies (Arix...

Thank you! So yes, small buffers, no termination (RCD1 to 7 are not installed), as expected - but better to be certain :-)

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...