C64 core problems.....

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DanyPPC
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Re: C64 core problems.....

Postby DanyPPC » Sun Apr 23, 2017 2:17 pm

New updates with test on other games,

...more to come.

braincell1973
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Re: C64 core problems.....

Postby braincell1973 » Sun Apr 23, 2017 2:36 pm

Hi. Tap support isnt coded past loading the file yet . It was to be after the CRT support.

The t64 works as well as prg but with a few caveats.
It loads the first file only and uses the load address in the t64 header

CRT support is ,so far .. 8k/16k generic carts work 8k ultimax now works (seems there was NO vicII ultimax mapping in core so the character rom went walkies ) ocean carts should work and magic desk should work (domark/activision), thats when i started getty funky results with code that looks logically correct.

I guessed i broke the jiffy loading when i changed the load addresses in sdram for carts and taps. Will correct that later but the beta was only meant for facebook just to double check these odd results i was getting it is certainly not ready for public consumption yet.

Lee

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Re: C64 core problems.....

Postby mambrino » Thu Apr 27, 2017 7:22 am

New updates added to google sheet.

Thanks for working in improving this core ;)

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Re: C64 core problems.....

Postby lips2k15 » Sun Apr 30, 2017 12:00 am

How do I get my Jiffydos roms to work with the beta?

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Re: C64 core problems.....

Postby braincell1973 » Sun Apr 30, 2017 6:26 am

Explanation above :)

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Re: C64 core problems.....

Postby Julitium » Sun Apr 30, 2017 3:28 pm

Hi.
Congratulations on initiating some improvements needed to get closer to a real C64.
I hope to be able to help in the development of these improvements (but I have no knowledge of VHDL or Verilog).
I am not a guru, but I can help you with hardware.

How can I download the beta ??

On the other hand, the JiffyDOS not have problem .... Taps and Jiffy are not compatible either in the real machine (the part of the rom that handles the tape routines is replaced by the acceleration routines), so it Logic is to use the standard rom or Jiffy as before.

Electronically Tape Port:

read pin is connected to pin |FLAG (note 1) of CIA 1 (DC00 to DCFF) (Input).

write pin is connected to pin P3 (of CPU) (output) (need for implement?).

CASS motor is connected to pin P5 (of CPU) and is used to start/stop/continue the .Tap decoder (output).

CASS sense is connected to pin P4 (of CPU) and is used to detect any key pressed on tape deck (it must be ever active(low?) on TAP decoder)

+5V not used on Implemented system

GND not used on implemented system

Note 1: |FLAG pin is implemented on FPGA64 from v0.18 (CIA has flag_n input).
I Maybe it should be inverted and synchronized with the system clock (attention to this).


http://www.zimmers.net/anonftp/pub/cbm/ ... tte-io.gif

very explanatory links about the .Tap format of C64 and as this works with tapes (They explain it better than me).
At hardware level, I wait for your doubts or comments. I hope to help you.

http://c64tapes.org/dokuwiki/doku.php?i ... ng_loaders
http://unusedino.de/ec64/technical/formats/tap.html
http://www.zimmers.net/anonftp/pub/cbm/ ... aticP2.png

Hope this information is helpful.


Very Thanks again.

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Re: C64 core problems.....

Postby braincell1973 » Mon May 01, 2017 4:17 am

Hi.
Thank you for the info.

My knowledge of c64 internals is pretty solid.the difficulty with the tap format is not the implementation but reading from sdram on a cycle thats not being used by vic/cpu/iec/dma io.

But i have a good idea how to sort that :D

I simply havnt got to it as this bug stopped me in my tracks. So i will resume with the crt and then the tap when this is resolved.

Lee

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Re: C64 core problems.....

Postby braincell1973 » Thu May 04, 2017 7:45 am

Hi All,
Now back from holiday, I have emailed the cores original author as maybe he has corrected this already.

Who knows maybe we can get lucky and find this needle in haystack.

Google sheet looks good, at least i can look for the commonality between games now, But, Please keep adding new ones.

I have purchased a 1541-II and dug out my old breadbin so i can check results on real hardware.

Should anyone have any ideas about the suspected cause please post......

My 6502 is somewhat rusty so going to start (slowly) investigating this problem using vice. :D

Lee

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Re: C64 core problems.....

Postby vebxenon » Thu May 04, 2017 8:30 am

Who is the author you have emailed? :-)
Just a computer and videogame lover :)

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Re: C64 core problems.....

Postby braincell1973 » Thu May 04, 2017 10:55 am

Hi,
The FPGA64 author Peter Wendrich (pwsoft@syntiac.com)

I know its a longshot but worth a try as its closed but actively developed for the Turbo Chameleon.

I also checked the changelog since it went closed for clues :D

*edit* CIA code is from MIKEJ and i found updated code at fpgaarcade

CIA code is updated (a lot) from the version in c64 core - i will try incorporating fixes :D

Lee
Last edited by braincell1973 on Thu May 04, 2017 3:13 pm, edited 1 time in total.

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Re: C64 core problems.....

Postby NML32 » Thu May 04, 2017 1:35 pm

:cheers:
That's good news

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Re: C64 core problems.....

Postby vebxenon » Thu May 04, 2017 3:21 pm

Good news :cheers:
Just a computer and videogame lover :)

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Re: C64 core problems.....

Postby ericgus » Thu May 04, 2017 6:47 pm

Ill say it a hundred more times but thank you for championing improving the C64 Mist core..

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Re: C64 core problems.....

Postby braincell1973 » Thu May 04, 2017 6:48 pm

What a total pilchard - Mixed up my 6526 with 6522 *facepalm*

Anywhoooooo, MIKEJ had indeed updated the 6522 code and i just compiled it into the C64 core - Need to test but so far no ill effects :D

(at least when i get to the 1541 it should have a little bugfix already :O )

Im still thinking that the CIA could be the cause of this , So, Looks like i will find a datasheet and investigate.

Lee

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Re: C64 core problems.....

Postby DrOG » Fri May 05, 2017 3:06 am

:D Great news!!! :D

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Re: C64 core problems.....

Postby Higgy » Fri May 05, 2017 11:35 am

Great work braincell1973 - there seems to be negativity about improving Cores so well done in keeping at it. Just please make sure your mods don't mean your Core only works on MiST's with Holy Grail chips and not on others :lol: (SDRAM timing issues/FGPA variations? -not sure we have got to the bottom of it, yet...)

To everyone - A slight deviation regarding JiffyDOS - I like to watch scene demos, and I read that a lot of demos incorporate their own fastloaders/drive tricks and that JiffyDOS can actual cause issues. Is this correct? I know a demo I was watching the other day stopped some minutes in with the access LED just flashing?
Thinking about it - could JiffyDOS also cause tape loading issues?

I need to create a SDcard with a non-JiffyDOS Core to re-test the demo to see if that is a potential issue.

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Re: C64 core problems.....

Postby braincell1973 » Fri May 05, 2017 11:53 am

Hi,
As this problem is on the ZX-Uno too im confident it is a core problem and not a mist problem.

As the majority of software works this is definitely an obscure bug.

JIFFYDOS does indeed foul some demos and DEFINITELY does not work with tape as the turbo loader code resides in the tape code area IIRC.

Im hoping that i can find the problem but it could take a while, As of yet no reply from the original author :(

As the CIA controls timers, some interrupts and VIC access i am hoping this is the cause of the weird GFX corruption / input problems.

Lee

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Re: C64 core problems.....

Postby ericgus » Sat May 06, 2017 5:56 am

Higgy wrote:Great work braincell1973 - there seems to be negativity about improving Cores so well done in keeping at it. Just please make sure your mods don't mean your Core only works on MiST's with Holy Grail chips and not on others :lol: (SDRAM timing issues/FGPA variations? -not sure we have got to the bottom of it, yet...)

To everyone - A slight deviation regarding JiffyDOS - I like to watch scene demos, and I read that a lot of demos incorporate their own fastloaders/drive tricks and that JiffyDOS can actual cause issues. Is this correct? I know a demo I was watching the other day stopped some minutes in with the access LED just flashing?
Thinking about it - could JiffyDOS also cause tape loading issues?

I need to create a SDcard with a non-JiffyDOS Core to re-test the demo to see if that is a potential issue.



don't forget the 1541 portion of the c64 core also needs a lot of love too.. so it could be that as well.. until both are given a proper once over your milage may vary jiffydos or not.

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Re: C64 core problems.....

Postby braincell1973 » Sat May 06, 2017 8:37 am

Yea.
I agree but working on the 1541 or anything else needs to wait until fundamental problems are eliminated to stop fighting a war on 2 fronts :)

I have however just purchased a mint 1541-II from iretrovolver and a couple of cheap logic analysers from zbay for (much) later on :)

At some point im going to compare the mist behaviour directly to 1 of my 64s to try and nail this down.

Seems that my lunch hours are never long enough lol

Lee

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Re: C64 core problems.....

Postby ericgus » Sat May 06, 2017 3:07 pm

braincell1973 wrote:Yea.
I agree but working on the 1541 or anything else needs to wait until fundamental problems are eliminated to stop fighting a war on 2 fronts :)

I have however just purchased a mint 1541-II from iretrovolver and a couple of cheap logic analysers from zbay for (much) later on :)

At some point im going to compare the mist behaviour directly to 1 of my 64s to try and nail this down.

Seems that my lunch hours are never long enough lol

Lee

Yup totally agree 100% .. and I suspect once you get the 64 part squared away the 1541 will fall in line shortly thereafter.. (i.e. the 1541 will probably be an easier task as they are similar to a point)

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Re: C64 core problems.....

Postby Brt » Sun May 07, 2017 6:04 am

Thanks for Your effort in perfecting the core.
It's really great job!

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Re: C64 core problems.....

Postby Sorgelig » Sun May 07, 2017 6:36 am

check the sources of 1541-II - it should be more advanced than FPGA64.

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Re: C64 core problems.....

Postby bernouilli » Sun May 07, 2017 7:25 am

I hope the c64 will be able to write on d64 soon.

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Re: C64 core problems.....

Postby seastalker » Sun May 07, 2017 11:50 pm

I am sooo appreciative for this... I hope someday to be able to create cores or help update them.

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Re: C64 core problems.....

Postby braincell1973 » Mon May 08, 2017 7:51 am

Hi All,
As i have said previously this is a learning curve and i have a plan, 1541 is much later, I have purchased 1 if i need to do direct comparison but reading works well enough for now.

I had a brief message with QUEST over at ZX-UNO who has been looking at this problem too and we are in agreement the CIA (most likely) and or VIC is the problem.

But whatever i can get done will be in spare time so nothing will happen too quickly at the moment.(RL intruding)

I have the datasheet for the 6526 and i will look for some CIA test progs from google and see what happens, Once my (cheapo) logic analyser arrives i may hook up a real 64 and run the same progs on a real 64.

I am very doubtful these problems all stem from a single bug so will start with the CIA and go from there.

Lee


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