Unicart64 - The FPGA based cartridge for Commodore 64

Hi,

I have identified the place where it is hanging on (red screen). Oh, how good it is I have added color identification/diagnostic .
I have also theory how to improve it, but it is about timing - number of waiting cycles when the C64 and FPGA is powered on and the SD controller is initialized.
When FPGA is loading firmware it takes for a while. The C64 power on sequence takes a while as well. And it seems to be there are differencies in this timing between C64 boards.
I believe that I have to wait longer time in my starting code - boot Ultimax cartridge.
Unfortunately,
1) I have no such C64 machine to test it.
2) The code is part of FPGA firmware.
If you need to change it, you need reflash FPGA firmware, you will need USB Blaster Rev.C programmer + Altera Quartus Studio installed on your PC.
What to do ? I can only check the theory in reverse way, I will set lower number of cycles and my expectation will be I will end in red screen as well.
I strongly believe I will solve this problem. Only confirmation will take a time.

Thanks all, perfect inputs and good night.

Hi,
No imagine ... I only know it is Altera stuff. Quartus studio generates for me the following:

.SOF - I think this is JTAG connector debugging format, directly to running FPGA (I don't have connector on the board, not supported)

.POF - this is "AS interface protocol", this is used for my board, supported in my board. This file is flashed to Serial Flash, not directly to FPGA. If you are able read this format/understand it and you are able to send it to Serial Flash + some signals are set to block FPGA during flashing it could be possible.

But, I think the programmer USB Blaster Rev.C is widenly available for 3-5 $ + free shipping, everywhere on internet shops .
Quartus Studio is free ...

Only waiting is around 1 month. Unfortunately I have only 1 piece and I need it. This could be investment for the future firmware flashing, not bad to have it.

Here is photo ...
20180802_103047-mod1.jpg

Meantime ...,
I send you my examples of Cartridge Starters - small programs to start cartridges directly from SD card inside SDCMDUC.

You can load it to your SD card and if you need just start your selected type of cartridge from ROM/RAM.
This is dedicated to my memory map, but most of it will work for you.
TEST-STARTERS.zip

Example:
Start SDCMDUC somehow ...
1) Uploading CRT to RAM: Navigate .CRT file, press "Return", select "RAM", wait and "Return".
2) Starting CRT: Navigate starter program e.g. "START-RAM-AR.PRG", press Return. The AR should start automatically.

code details ...

CONST cUC64_IO2RAM_PAGE = $DE05 ; map page IO2RAM register
CONST cUC64_IO2RAM_BANK = $DE06 ; map bank IO2RAM register
CONST cUC64_IO2RAM_SLOT = $DE07 ; map slot IO2RAM register

CONST cUC64_CRT_BANK = $DEFD ; map bank CRT register
CONST cUC64_CRT_SLOT = $DEFE ; map slot CRT register
CONST cUC64_CRT_START = $DEFF ; start CRT register
...
LDA #$00
STA cUC64_IO2RAM_PAGE
LDA #$00
STA cUC64_IO2RAM_BANK
LDA #$00
STA cUC64_IO2RAM_SLOT

LDA #$00 ; always bank 0, bank is defined in CRT header ...
STA cUC64_CRT_BANK
LDA #$09 ; Slot-9 ( Flash ROM slots: 0..7, SRAM 8..15, only slot 9 is used by SDCMDUC in case of RAM)
STA cUC64_CRT_SLOT
LDA #$09 ; this is code for AR
STA cUC64_CRT_START ; resets hardware , board is now AR

--> RESET/BOOT

Some limits for SDCMDUC 2.4:

- Directory will display max. 255 items (dirs+files).
- No sorting. Hint: If you will copy files, delete all files in directory and copy all of them on PC. Then, the files will be sorted like on PC.
- There is FAT32 long filename support, but only max. 255 chars / file (original is 260 ...).
- The current directory is loaded to C64 RAM. The buffer for all filenames in directory is max. 24 kB (theoretically 64kB) placed $A000-$FFFF.

Hint: I support 3 screens/views. Press "S" to rotate all screen views.

If you exceed limits, no error will come, just your file list will be not complete !
Happy browsing .

Hint for REU demos ...

1) Navigate REU demo .PRG file in SDCMDUC
2) Press Shift+Return (not only Return !), file will be loaded into C64 RAM, but not started !
3) Type POKE 56832+255,12, press Return ( code $0C into $DEFF), now the board is REU 8MB !!!
4) RUN, press Return

Happy watching .

Kernal .bin file convert to .CRT file (I have used HexEdit only ... ) and flash it or upload it to SRAM.
Then, create your starter program, similar to my one.

OK, my stuff is flashed in Slot-4.
My ROM starters are dedicated for slot-4 only.
SLOT-4 BANK-00 KERNAL-0
SLOT-4 BANK-01 KERNAL-1
SLOT-4 BANK-02 KERNAL-2
SLOT-4 BANK-03 KERNAL-3
SLOT-4 BANK-04 KERNAL-4
SLOT-4 BANK-05 KERNAL-5
SLOT-4 BANK-06 KERNAL-6
SLOT-4 BANK-07 KERNAL-7

I have collected that and created one bigger .CRT, I was too lazy to do it by one ...
kernals.crt

Try starter for KERNAL-4 or 5 for JiffyDos, I don't remember.

You can create .crt for 1 bin file only and load it to SRAM to Bank-0 as well.
Then use my START-RAM-KERNAL.PRG.
JIFFYDOS.crt

Hint to start EasyFlash image after power up of C64.

Here is example of very short bootfile, which redirects running to EasyFlash image in slot-0.
Just try to flash your EF image into Slot-0 and replace my SDCMDUC bootfile by this EF bootfile.
start-files-reset-ef.zip

Simply you can create what you want.
The detailed info for developers I plan to publish soon.

Enjoy !

that's feature, no bug ...
If you start Kernal cartridge the rest is disabled.
At the beginning EasyFlash, IO2RAM and SD card controllers are active,
but after switching to Kernal all 3 controllers are disabled.

Zitat von Diddl

is it possible to buy such a cartridge?

Hmm, currently I would like to solve some issues ... But, once it will be better for ASSY 250407 I can continue.
For now, I can reserve 1 board for you.

Thank you borstie for your tests !
It is valuable for me very much, more symptoms bigger chance to improve it.

Zitat von borstie

Tests:
1.1. Writing kernals.crt in flash memory did not work: hardware error (prompt with loading sdcmduc via disk)

Hmm, it sounds like this is clock/timing general issue. This ASSY 250407 has different timing, probably.
I should think about what to do ...

Zitat von borstie

Writing kernals.crt in flash memory works, booting via starter did not work: C64 crashes on every slot

This is on 250469 ... it should work. How did you test it ?
Try flash the kernals.crt into Slot-4, please. And try my ROM KERNAL starters 0-7.
It should be working.
Please, let me know.

I send you my experimental FPGA firmware:
UC64_2019-02-04-red-screen-problem.zip
It will give me the answer if I have solved "red screen" / booting problem.
Yes or No. To be or not to be !
Please, once you will be able to flash it ... send me the answer.

I have also updated the user guide.
2019-02-04-Unicart64-user-guide.pdf
added: FPGA firmware programming using USB Blaster Rev. C

I have also updated the FPGA hardware guide for you.
2019-02-06-Unicart64-hw-guide.pdf
Now, everyone should be able to create his own FPGA firmware.

And finally. I have started with the Firmware documentation.
2019-02-06-Unicart64-fpga-fw-guide.pdf
Now, everyone should be able to create his own software for FPGA firmware UC64190124.
... will be updated in the future.