Hello. I'm new to NeXTStep, and the black hardware. Honestly, I have used it, but I don't have anything handy currently. I'm doing some footwork for a pet project of mine, and I have a few questions that I cannot easily answer, but the combined knowledge of this board might have answers.
The main question is how easy is it write a custom interrupt? I happen to know a lot about 68040 processors, and it occured to me that I can UPx bits to do a MMU mapping that would let me possibly expand the bus with some custom hardware; however, I don't know the details on an OS where I cannot explicitly edit the kernel code.
Has anyone ever written a custom interrupt for NeXTStep?
I don't know about custom interrupts, but the OS and bus are set up to be used in a multiprocessor mode. The Dimension, for example, runs it's own little OS, and NeXTStep and the Dimension communicate over the bus... kind of like a high speed interconnect.
So, the NeXT guys multiplexed the bus on the slabs. I don't know anything about the Cubes. 10 years ago, Pergamon was nice enough to loan me a slab. I was going to see if I could make a socket modification that would allow me to get some IO out, and put a memory card there. I'm trying to replace the 2.88 floppy with a SD card. The hardware is pretty straight forward, but I don't know about the software side of it.
Basically, it comes down to how to get data out/into the bus. Using the UPx pins, I can setup a transfer to memory by some logic, but the software side of it looks like I need an interrupt.