Posts by mega65

    The funny thing is we had it rock solid before we made the CPU timing 100% exact. So I am guessing there is some subtle timing thing going on. But I won't have time to look until we finish moving. So any investigations you are able to do in the meantime would be great. For example, make a routine that toggles the IEC lines at some known fixed frequency, and compare from real C64 to MEGA65 to look for differences, e.g., if the frequency is wrong, or there is a lot of jitter.


    LG

    Paul.

    FeralChild if you can do some experiments to see if there is any timing difference on the IEC port when you waggle lines compared with a real C64, that would be super helpful. I haven't had the chance to try to document what exactly is going wrong with this. In theory, M65 is cycle accurate at the instruction level, but not at the cycle level, but the IEC protocol should have ample slop in it to allow for this.


    One known issue is that C128 style loading iwht the SRQ line probably won't work right now. But all drives in C64 mode should work just fine -- unless we have something else borked.


    LG

    Paul.

    MEGA65 hardware doesn't support it, and might not for a while, as it requires an extra BRAM. T100 based boards are unlikely to get support for it, due to this. So I'm inclined to just not implement it, since very little existing software (if any) depends on it.


    LG

    Paul.

    Ok. Let me try to flash it here, and see how it goes. Latest bitstream for me boots fine to OpenROMs (I don't have an SD card in it). Confirming that it doesn't seem to load the bitstream for me here, either. I'll try to take a look when I get a moment. But you can build the same bitstream as me from the head of 138-hdmi-audio-27mhz branch.


    LG

    Paul.

    Howdy folks,


    Glad to hear several of you are alerady getting under way, and making nice progress.


    I'm in the middle of moving back from the Outback to the city at the moment, so my time is a bit scattered at the moment, but I will do what I can to help.


    Also, what would be great, would be if you greate github repos with your favourite workflow automated with a helloworld.c or helloworld.asm etc, so that others have a nice easy starting point, e.g., with Makefile if that is your prefered way of doing things. Then bonus points for writing a bit of documentation on the use of it, and getting setup on your favourite "big" OS, so that we can expand the developer's guide to help others.


    LG

    Paul.

    ok. Fixed it now. Corrected programme is below, and will appear in updated book soon:


    10 RESTORE 110:FORI=0TO43:READA$:POKE1024+I,DEC(A$):NEXT:BANK 128:SYS1042

    20 S=PEEK(1056):M=PEEK(1057):H=PEEK(1058)

    30 D=PEEK(1059):MM=PEEK(1060):Y=PEEK(1061)+DEC("2000")

    40 IF H AND 128 GOTO 80

    50 PRINT "THE TIME IS ";RIGHT$(HEX$(H AND 63),2);":";RIGHT$(HEX$(M),2);".";RIGHT$(HEX$(S),2)

    60 IF H AND 32 THEN PRINT "PM": ELSE PRINT "AM"

    70 GOTO 90

    80 PRINT "THE TIME IS ";RIGHT$(HEX$(H AND 63),1);":";RIGHT$(HEX$(M),2);".";RIGHT$(HEX$(S),2)

    90 PRINT "THE DATE IS ";RIGHT$(HEX$(D),2);".";RIGHT$(HEX$(MM),2);".";HEX$(Y)

    100 END

    110 DATA 0B,80,FF,81,00,00,00,08,00,10,71,0D,20,04,00,00,00,00

    120 DATA A9,47,8D,2F,D0,A9,53,8D,2F,D0,A9,00,8D,02,D7,A9

    130 DATA 04,8D,01,D7,A9,00,8D,05,D7,60

    Hello,


    Sorry, I have been (and continue to be) quite busy moving back from our Outback Hideout to rejoin the real world. Whether that's actually a good idea, I leave for a separate debate ;)


    Can you please send me the bitstream you made? I have an original N4 board here as well, so I can test it here.

    Did you also try just pushing the bitstream via jtag directly, i.e., not via flash?

    Also, did you set the jumpers for "boot from QSPI flash"?


    Auch sag mir nur bescheid, wenn du bequemer auf Deutsch gehen möchtest.


    LG

    Paul.

    Hello,


    The C65 doesn't have a mechanism for this, but as ubik mentioned, you don't generally need to do it on the MEGA65, because there are easier ways to move the character data point around. You CAN also change the data in the character "ROM" on the MEGA65, but generally shouldn't need to -- and shouldn't assume that the changes will be kept after freezing.


    LG

    Paul.

    Jesper - I wonder if it makes sense to have some mechanism for KickC to attempt to "phone home" to find missing fragments, so that you can just put them up on web somewhere as you create them?


    Also, Jesper and I did some work a year or two ago on automatically generating fragments from their descriptions. If someone were interested in continuing that work, it would be quite helpful, I suspect.


    LG

    Paul.

    The MEGA65 core is "mostly" finished, but there are still bits and pieces being worked on. For porting to the MISTer board, the main outstanding item is a rework of the memory sub-system, that I am hoping will be done in the next few weeks. This should make it much easier to port to different boards that don't use Xilinx parts, or use external SRAM etc.


    LG

    Paul.