Recent content by Melkhior

I'd recommend a real connector, preferably some sort of modern high-speed high-density connector. It helps with signal integrity issue and with mechanical support. Look at what is available in large quantity at JLCPCB, and that should be popular enough to be somewhat future-proof. (edit: i will...

Oh, OK, did not know that, I thought Apple had standardized the Quadra PDS for all Quadras (that have one, so not e.g; the 840AV).

The linux 2025.2 might remain usable (though it calls home, so you never now...), and the 2026.1 on Windows still has a free license though for one year only. So it's not entirely dead. I'm not sure what you mean; you want to plug a card-edge in the PDS slot ?

Yes, it's very short-sighted. Having really great support for your FPGA freely accessible to those who won't/can't pay is a great way to lock-in mindshare and expertise. Hobbyists, students, small companies were using those licenses. Without them, people are going to look at alternatives...

Darn. No more lifelong licenses, it's all annualized now (so they can change the terms more easily I suppose), and the new free version is only on Windows not Linux...

Mine is SMT as it's not expensive to get the SMT done byy JLCPCB, and it avoid having to source and deal with the small discrete parts. The big connectors (which are also the most expensive parts) are easier to stock and handle for me. The reason I did my own is the little switch to select...

It was likely OpenLDI/LVDS to support the SGI 1600SW, as Formac resold those. The Permedia 3 chip was the consumer version of the 3DLabs chipset found in e.g. the 3DLabs Oxygen VX1, which also had a version supporting the 1600SW. Anecdotically, the Permedia 3 accelerated framebuffer driver in...

Qualified no, on machines without a MMU the ROM (and System) map the non-cacheable area (i.e. everything that isn't physical memory) to a "transparent" 1:1 mapping. However, there's still the 24-bits vs. 32-bits addressing to handle. LC might commonly run in 24-bits (can't remember if they can...

@Jockelill is proposing a NuBusFPGA carrier; those should work in any NuBus machine - most compatible, but slowest bus. Testing a design using the PDS slot for the MC68030 is more complex, as the machines with those PDS slots are all subtly different - the IIfx has the clock on a different pin...

Poor simms :-) The devices aren't limited to 3.3V on the power rail only; usually, the driver/buffer at the pins are also limited to 3.3V. Using 3.3V SIMMs in an unmodified 5V machine is likely to damage the DRAM chips. You're also potentially overloading capacitors - if there's traditional...

Everything but the DIN connector was done at JLCPCB (there's a LOT of 0402 capacitors on the backside, plus the oscillators and the flash for the FPGA). The DIN I soldered myself because I can do it and through-hole is expensive at JLCPCB (and they didn't have the connector in stock).

Not yet, still need to sort out the burst read issue and do more testing. Also I'm in Europe, and shipping to the U.S. has been too complex for a while, should I sell my surplus board it will be more locally (shipping internally in the E.U), sorry. Source and production files are on GitHub if...

Somewhat more expensive. And you need a different connector than the one used in the originals NuBusFPGA V1.0 and V1.2, as those are too low-riding on the PCB for the cable to fit in the slot adequately. An internal connector, small cable, and a proper 3D printed backplate would be a cheaper and...

The problem is only the size of the board - the bigger they are, the more expensive... you don't want to build something the size of a NuBus board if you can avoid it. In particular with more layers and/or more sophisticated processing. hehe, perfect timing: IIsiA7 Mini. My first design with...

I just use the board with a (homemade) riser with two PDS slot, so I can also have my (homemade) version of the SEthernet/30 and get Ethernet. For now I haven't bothered to make things pretty by having a proper backplate, I just run the cable to the inside of the machine... a bit 'yuck' but it...