Gigatron Hackers

Neat! That looks a bit cleaner. I would love to hear a comparison.

I'm still gaining ideas and working out logistics before embarking on my own creation. On the vCPU coprocessor idea, a smaller step might be just to enhance the native opcodes to have more hardware available for the vCPU, focusing on opcodes and minimal hardware that would make the current vCPU code...

Yes, as I said, this is just a unified list of possible mods and not put here with specific plans. I might use some of these in my eventual design. The goal did not specifically include a list of architectural design plans. It is just a unified place for a "wish list." Now, if others want ...

Yes, finding ways to hack older hardware is fun. The 6502 had "illegal opcodes" that many coders would use. It's neat what add-ons folks are making for the Atari machines. Someone had made a driver for running a parallel printer on an Atari 800 using the joystick ports. Someone even manage...

I would try attaching a Famicon controller and seeing if it works as expected. If not, then you might want to check the wiring around the port and the resistors on the Gigatron side. But if that does work fine, then it could be your Pluggy or your keyboard. You might find some assistance by looking ...

Thanks! I added to it over several days. I don't know how many I will implement once I get ready to implement it in FPGA. It seems that I'm thinking of making it more as an Asymmetric Multiprocessor (AMP as opposed to SMP) APU and mostly a SOC design. I could see someone like David Murray ("The...

Here is a list of as many possible Gigatron modifications I can see. Keep in mind that this list is only to give ideas and inspire creativity. Nothing said here is to be taken as a criticism of the platform. The Gigatron is already beautiful as it is. Opcode Mods Add more memory addressing modes -- ...

I've learned a lot by studying the Gigatron over the past year even though I haven't built one or owned one yet. As I've played with ways to mod it in my mind, I've learned more about why various decisions were made. I've asked myself many questions such as, "If I change how this is done, what ...

Yes, the Gigatron is marvelous as it is. And I think the term for the adder mod would be a carry select adder. If one is going for an optimized 4-layer PCB and possibly SMT parts, I think the carry select design would help push for a higher clock rate or improve stability at higher frequencies. If o...

I started studying the RCA 1802 . I am pretty sure the Gigatron can outrun it, even in vCPU mode. It was a somewhat odd CPU. It uses 8 clock cycles in a machine cycle, and instructions take 2-3 machine cycles. That means it takes 16-24 clock cycles per instruction. The instruction length is 1-3 byte...