Gigatron Hackers

I think I know how to get a discrete chip Gigatron up to 50 Mhz. Do it using SMD, do a LUT-based control unit shadowed into 8 ns SRAM, shadow the instruction ROM too, use 3 pipeline stages, use Drass' 6.7 ns ALU, and use 8ns system SRAM. Unless the SRAM can be uncoupled, about 66.667 Mhz would be th...

I guess I could add here to prevent starting a new thread. I believe that adding a new pipeline stage would push you right to 18 Mhz. By that point, the CU and the ROM would be the bottlenecks. While a 3-adder ALU would cut some latency from the ALU stage, the other 2 stages would be the bottleneck....

With the video coprocessor idea, I worked out some other questions. If one wants to dedicate an FPGA board, one would probably want to add as many features as possible. I mentioned using it for higher math functions too. That raises the question of where to put the FPU "register" area. Aft...

This sounds fascinating and impressive considering the hardware. If/when I do the FPGA build, I think I'd want to try a hardware multiplier. I'd probably opt for 4 nibble LUTs with the whole process taking no more than 3 cycles. Using this approach, 2 8x4 LUTs would be better, but I'd likely go with...

I am curious what others think about the idea of an output-only snooping controller. That seems like a less-intrusive mod and really doesn't require a new board, although it would be a good thing, IMHO, to include on a respin. It could be made onto a board that plugs into the SRAM socket. Purists wo...

Many of us have pondered ways to get the video processing out of native code. I've pondered different ideas over the past couple of years. This thread is intended to be a place to have them in a unified place. Partial Measures First, we start with partial measures. For those who don't want to use th...

I have more understanding of how the Gigatron works since I've started this thread. To be honest, the CPU portion doesn't need port opcodes at all. The 6502 didn't have them. More native opcodes, including shifts, registers, and memory modes, would have a higher priority to me. As for the ports, you...

And if someone could make a keyboard to fit in a similar box...

Thanks, Walter. I do have a project page there. I'm doing more sharing than looking for advice. I tried on AnyCPU, but I find I don't fit with that crowd. Yet, my project seems to be beyond the intended scope here. Below is the logic as to how I got to this point in what I'd like to build. The chall...

I've wondered, if I were to make my design, if I even want to copy the vCPU or memory locations. On one hand, I could do things differently and make use of special features. But then one would need to create a toolchain and software environment. What does everyone think? I've considered splitting th...