Unicart64 - The FPGA based cartridge for Commodore 64

Quote from eadzon64

I also declare my BiG interest at one of this
great work!

OK, thanks for your interest, reserved last one for you.
I have no other free boards.

Quote from borstie

2. Assy 250407, Vic ?

Same behaviour as before:
This one did not boot reliable with the cartridge, sometimes red screen, sometimes black screen, sometime normal prompt without run/stop.
2.1. If i get the normal prompt i can load the sdcmduc via disk, it shows the firmware number and ok.
2.2. Starting a kernal with tha starter program: ok.

Thanks borstie also for negative answer !

Can you (or someone else ...) perform "RAM test" on ASSY 250407 ?
I give you patched version of EasyProg 1.7.0.
easyprog-1.7.0.zip
Menu --> Expert --> RAM test.
If borstie reported flashing problem, I would like to know, if SRAM writing cycle does the same.
My new theory is wrong/unstable writing cycle.
Thus, I expect problems there as well. Pls. test it also on 250469, just for the comparision.
Thanks. I'm looking forward .

Quote from Diddl

I have an USB Blaster here.

OK, perfect, I hope I will be able to send you another experimental fw for testing.
Now, I need time to understand why writing (? ...theory) doesn't work.

Many thanks, OK, let it be ... there is general timing problem on the PHI2 clock, my theory is during writing cycle (from symptoms)...
Now, It is up to me to analyse it and try to provide some experimental FW.
I need some time.

Thank you for your BIG help!

Hi,

After analysis I have suspicion that main O2 (or PHI2) clock is not regenerated correctly.
This is fundamental signal and many other important signals are derived from this one.
For details, you can look at this thread.
Fragen zu PHI2 Edge Recovery

But, I don't see original input O2 and/or FPGA interpretation of this signal from assy 250407.
I'm like a "blind" now. I just guess how it looks like. Normally, it is corrupted for every assy.
Here is example of this "corrupted" signal (FPGA interpretation) on assy 250469.
o2-clock-distortion.png
My regeneration logic tries to create nice jitter-free O2 signal for my FPGA.
And, I don't know if this job is done 100% for assy 250407.
Thus, I have prepared the experiments, I have just changed some parameters in regeneration logic.
Here are firmwares.
UC64_2019-02-11-clk-i44-111.zip
UC64_2019-02-11-clk-i45-11.zip

But still, we don't see the input, and we don't see the output.
It would be nice to have some logic analyzer (e.g. Saleae etc.), oscilloscope to check it. If you have it just let me know.

Hi,

Here is another fw prepared for testing.
Original fw, I have moved only 1 sync point for SD card.
Here is precondition, regeneration is working 100%.

UC64_2019-02-12-sd-34-37.zip

Please, if you have time test it as a priority, assy 250407, only boot test/commander browsing.
Thanks.

Peter

Quote from borstie

I have a logic analyzer and an older scope but i'm afraid i will damage the cartridge if i measure directly at the fpga pins or if i would solder some wires to the pins to do the measurements.

No, no, no soldering ... first let's try my firmwares and later only in case of fail, we can go to show clock.
In such case I will guide you & produce special fw to redirect internal reg. clk to LED1 - connector "D1" in top of board.
It is possible to do without soldering. OK, later.

Continue from post #90 ...
UC64_2019-02-15-sd-ramcode.zip
workaround just to test, original rom code was copied first to C64 ram, boot crt deactivated and boot started ...

Quote from wolfme

It's no longer possible to program FW, verify of all programing tries with all FWs fails:

It seems to be missing power supply 5V from C64 side ... Did you turned on C64 ?
Follow my guide. Hopefully, nothing bad happened .

Unicart64 into C64 (without SD card is better).
Plug in programmer.
Turn on C64 (as power supply 5V) !
Start programming.
...

In this moment no idea what to do.
Was there progress bar for programming and then failed to for verification ?
Or simply nothing and failed ?