I started working on DMA support and got it most of the way there, but then some of my tests were acting weird. After digging into things with GTKWave a bunch it looked like both 16-bit loads and stores were […]
I’ve been reading through Linkers and Loaders for the last couple months, and my brain is very full with toolchain stuff so I figured I’d think about hardware again for a little bit. I think DMA will probably just be […]
The next thing to implement is going to be exceptions, or traps, or faults, I haven’t really decided what to call them yet. We’ll need them for syscalls, page faults, breakpoints, and probably things I haven’t realized yet. My current […]
After a year away from the project (we adopted a puppy and then there’s been a pandemic), I got back into it today and picked up where I left off in 2019. I’d realized that the stack instructions had been […]
Spent a bunch of today working on microcode and a unit test for interrupts, and got it all working! There are now 8 working interrupt lines that support separate ISRs for each and have a priority system, and there’s a […]
Finished off the rewrite of the microcode assembler yesterday, the new one has now taken over as the reference implementation and is the primary microcode assembler used by the simulator. I still want to implement some optimization features later on, […]
I’ve spent a bit of time over the past couple of months re-implementing the microcode assembler from scratch. The original microcode assembler was thrown together to save me from typing 64 ones and zeroes for every word of microcode (which […]