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FPGABee, or other Kit? - elpiggio - 05-08-2020

I've been thinking about building some kind of retro computer board type kit, maybe an FPGABee. But which one? And where to start?

Are there any kits available for this or something similar?   (I might consider a generic Z80 or 6502 based board)


https://www.toptensoftware.com/fpgabee/


RE: FPGABee, or other Kit? - someone - 05-08-2020

Hi Elpiggio!

Someone's built discrete hardware, FPGA and emulated systems.

The decision of what type to build depends upon your planned journey towards the planned goal.

Building a real floppy disk controller using just an FPGA is a challenge with the most difficult portion being the data separator circuit.

Building from discrete hardware is the best learning experience because the machine can be built gradually from just a Z80 flashing a LED to a fully fledged disk system microbee.
After building a hardware machine, building and FPGA version is the similar but in a virtual environment.
And then there's the emulator/simulator option where you get foreign hardware to emulate the microbee hardware behaviour.

The DGZ80 from which the microbee is derived is an overly complex method of building a microbee.  Being an S-100 board it has the additional complexity for the S-100 Bus interface which requires 8080 hardware signal emulation.

A hybrid solution is also viable and I think that's what Ewan's done with his upcoming kit.  i.e. Discrete hardware with an FPGA.  However this hybrid approach is more complex with many more factors to address.

If you have an EPROM Emulator and EPROM Burner and oscilloscope - build it from discrete hardware.

If you need any help, just holler.

Cheers

Someone


RE: FPGABee, or other Kit? - elpiggio - 05-08-2020

Thanks. I wonder if I can emulate a Z80 Computer on the FTM-3SE Tower FPGA Module Spartan3E from Microbee Technology?

http://www.microbeetechnology.com.au/store/ftm-3se-tower-fpga-module-spartan3e.html


RE: FPGABee, or other Kit? - someone - 07-08-2020

You should be able to emulate a Z80 CPU based with this system.
Someone has already emulated a Z80 based system (a microbee) with Xilinx Spartan-3 devices.

You'd use something like Xilinx's ISE Webpack as the build environment and the T-80 soft core as emulated Z80 core.

https://www.xilinx.com/products/design-tools/ise-design-suite/ise-webpack.html

https://opencores.org/projects/t80


Monte Dalryple's articles and book on this subject are great reading.

https://www.elektor.com/microprocessor-design-using-verilog-hdl-e-book

Someone hopes that this information helps.