On Wed, May 30, 2018 at 12:05 PM, Jon Elson <elson at pico-systems.com> wrote:
On 05/30/2018 08:19 AM, Kyle Owen via cctalk wrote:
I'm thinking about trying to find a microcoded architecture to play with
before I design something around the Intel 3000 series.
Intel 3000? WHY!
Well, the Tesla clones were cheap and readily available on eBay! :)
I'd get an FPGA development board and download Xilinx's webpack software.
It would not take real long to design the basic microcode engine, and then
you could develop some application microcode in parallel with the hardware,
adding whatever feature to the hardware you needed when the need came up in
Yup, I've played around a lot with my Basys 3 board. But I like the idea of
writing microcode for an existing design (one that has a software
simulation as well as real hardware would be preferable), even though it
could likely run much faster on an FPGA.
I've got a MicroVAX 3800, so I suppose I could run MICRO2 to assemble the
aforementioned microcode. But then what? I assume
PALs would have to be
burned to implement the new microcode. Or is it more complicated than
PALs? I don't think the 3800 microcode was in PALs. I think it was in
CPU chip. There may have been a patch array that allowed a very small
number of microcode words to be overridden.
Yes, you appear to be correct; it's all internal.