first observable difference is immediately, that this board only has two PMOD connectors (compared to the 5 of the Nexys A7).
Which would mean, you couldn't use the DM65pic board to connect c64 keyboard and joystick.
The board also doesn't offer a microSD card slot, so you HAVE to always flash the bitstream into the fpga. you just can't test it quickly from an microSD card.
The core probably could run (it's the same Artix A7 100T) and it's using vivado to flash the bitstream.
(That's without checking much further).
If you really want to save some money, try it ! I would be interested as well in the results but you couldn't get much support from us, since we all use the Nexys A7 and let us know the result ! expect drawbacks and more !
I would suggest, try to find a student and get the academic discount of a normal Nexys A7.
My experience with things like this is, who buys cheap - buys twice....
... but like i said, it would be interesting to know if it works as a MEGA65
Really thank you for your quick reply. I will let you know IF i decide to use this board , or maybe try the more safe NEXYS 4 option
Searching a little bit futher this weekend I came up to theese facts:
I am wondering if we can just add a DIY SD card to second (cheaper) board.
Are there any specific infos which resources does MEGA65 core uses of Nexys4 board?
Thank you for your time
Finally I came to the following assumption/conclusion:
I think the only add-on you will need is a DIY board (according to the following Nexys4 schematics) connecting to Qmtech I/O pins:
With the above add-on & Qmtech 100T board you can use a usb keyboard (emulating C65keyboard) + sdcard
UPDATE: I dare to think that with the above DIY add-on board we can even use this Qmtech Core board for a quick 'dirty' MEGA65 coming alive!
It sounds very interesting !if you're following this road, please keep us up-to-date.If this works, it would really be the cheapest version of a real MEGA65 !
Unfortunetely after a work around pinout list ued in MEGA65 project from both Nexys4 DDR and Qmtech boards NOT all signals populated on Qmtech board!
So the above usage of theese (cheaper) boards is NOT an option for a low cost MEGA65 implementation
Possible solution: a way of re-maping the original pinout scheme used in MEGA65 project
Here is the pins that are used (but NOT ALLo populated) in order to implement VGA , SDCARD , RESTORE / IRQ , Keyboard in Qmtech board
and here it is the cheaper 80USD board pinout we must re-map the original to
I found this file on mega65-core on github: nexys4ddr.ucf
I think this is the one with pin assignment. Do you think I can just re-map the pinout or threre are dedicated pins for specific peripherals like VGA e.t.c?
Ok, so here is my current thinking on making a MEGA65 system from a cheap FPGA board:
1. We love that people are doing this!
2. That said, we are super busy getting the machine itself out, so we can't really provide any real support on this.
3. I'd actually go for this board: https://www.aliexpress.com/item/4000170003461.html
It's cheaper than the other one, and just has a bunch of IO pins, so you can make a widget board type thing for it with whatever peripherals you want on it.
4. You will need some kind of JTAG programming cable to talk to it.
5. Pinout of the connectors is at https://github.com/ChinaQMTECH/QM_XC7A100T_STARTER_KIT
6. To make a new hardware target for the MEGA65, you need to copy vivado/mega65r2* to vivado/newtarget*, then also change any reference to mega65r2 in those files to newtarget. Also check that you have changed the chip part if it is different. Then copy src/vhdl/mega65r2.vhdl and src/vhdl/mega65r2.xdc to src/vhdl/newtarget.*. Then change all the pin assignments in the .xdc file, and remove bits and pieces from your src/vhdl/newtarget.vhdl file to match.
7. Design up your new widget board for it, integrate, test etc.
This isn't totally for the light hearted, but it is possible to do (its more or less what we did with the MEGAphone prototyping.
I really apriciate Paul for your time. I will check this out.
Again congratulations you (and your team) for time effort .
Just noticed that there are no vivado/mega65r2* files in this repositoryhere , only mega65r1 files.
I don't mean to disturb Paul for support so this is a message for everyone else that could help me out.
Why I keep getting this error :package 'victypes' not found in library 'work' ?
I am trying to re-compile the original files but with no success.
I want just to make sure I can compile everything before move on changing development board for experiment.
Thank you for your time
Build from the commandline using:
If it fails, send me a copy of the vivado.log file, and I can try to figure it out.
Obstensibly, it may mean that victypes.vhdl is missing from the vivado/*_gen.tcl file that you are using for that target.
Well my friend unfortunately no success with compiling yet!
Here is my progress so far:
I followed this guide:
Installed Ubuntu 18.04 (on VM)
Installed Vivado WebPACK 2019.1 from Xilinx (in root opt/Xilinx dir)
tried to compile development branch with no success
(all installations as user in home directory ,except Vivado 2019.1 which is installed in root opt/Xilinx)
Noticed that could not even found the vivado.log file when run make from command line.
The only file exported is when I run Vivado 2019.1 graphical interface within Ubuntu (vivado.log created in user home dir)
It looks like the iverilog stuff hasn't built. Look in the iverilog directory, and tell me what you see there.
Hi Paul here is the info you asked
Really thank you for your help as I am trying to compile this for Cheap XC7A100T core board with DIY addon sdcard/c64 usb keyboard/vga/composite plugin board
so I really want to involve in some way with your excellent project / effort of yours.
for me it looks like Alex's Linux system is missing the autoconf command,
because when you look at the screenshot in post #35 you can see the line:
/bin/sh: 1: autoconf: not found
So I think you should check if the autoconf package is installed at your Linux system.
If not install it and try again.
I've just installed it on my Mint Linux system (which is based on Ubuntu) by the following Linux console command:
sudo apt install autoconf
TheChief / Markus
According to your thoughts my friend I think I made a little progress.
After installing autoconf the following needed to be installed too:
After all above steps conpilation (seems) to started as it should!
It starts compiling for minutes and now I get an error of Ophis
I have read somewhere of Ophis but I cannot find it . Please advice