2023-08-28

I looked at Ian Bradbury's ZX81 in SPLDs, intending to mop up some of the small-scale-integration chips (2 to 4 input gates)  that I don't have, into 22V10 logic chips that I do have. They're handy because they operate at 5V.

The logic is written in CUPL which is quite low level, like assembly language. Most designers have moved on to VHDL or Verilog, which are needed for today's big FPGA chips.

I thought I'd have a go compiling one of the ready-made designs.

There's a Cyclone II EP2C5 Mini Dev Board available dirt cheap and ZX81 code for it at https://www.qsl.net/yt2fsg/zx81/zx81_clone.html which I downloaded, unzipped and opened the project file from Quartus.

First of, it complains that my version of Quartus Lite, 20.1.1, will not compile for Cyclone II.
Okay, I told it to compile for Cyclone IV, which is the device on the DE-NANO that I have.

Next is complained T80s not found. This Z80 model is someone else's project, so I guessed I need to get the latest version.

I went to https://github.com/mist-devel/T80 and downloaded the files as a zip file called T80-master.zip which needed unzipping into a sibling directory called T80. It unzipped into a directory called T80-master so that needed renaming. That fixed that issue.

Now it moans:

Warning (12019): Can't analyze file -- file ../FPGA_ZX8x_shared/*.vhd is missing

where *.vhd is many files. The whole directory is missing! 

I eventually found this to be a better source of everything:

https://svn.mavipet.sk/svn/fpga_comps/HW_V1.0/

most of which are Cyclone II but FPGA_ZX81_Full does not get the Cyclone II error message. 
But I still get other errors!

2023-08-31