Hello,

this german distributor has replacements,maybe this is something you are searching for.I have one and it is ok.


http://shop.trenz-electronic.de/catalog ... ucts_id=78

Greetings,
Vassilis

Hello Andre,

Ok,so there must be something else wrong!? If you tristate the dataout then you get something like :



data <= "ZZZZZZZZ" when (dataout_en = '1') else (others => 'Z');



This would always tristate data independent of the status of the dataout_en signal.
So I would try to find out ...

Hello fachat,

first I would like to point out that I am a self educated hobbyist in all this and not a specialist! I have only tried to get an SRAM working an I am also not completely ready with it.There are many possibilities to write a state machine...

For my designs with tristates I try to keep ...

Hello all,



datain <= data when (phi2 = '1');



I think it is not desired to write a when condition for the input side.The CPLDs I have worked with (Xilinx/Altera) route the I/O Pin directly into the switch matrix.
Also most of them do not have an enable on the input side buffer in the io ...

Hello Ed,

thank you for the explanations!

Sharing the code is no problem.I have only made small changes:
- Removed some unused signals that were generating warnings.
- Changed binary opcodes like "00011000" to x"18" to be better readable.
- Added small comments to the opcodes when they were not ...

Hello BigEd,

I have made a picture of my small setup that I use to play with the T65 core.For different reasons I unfortunately have not made big steps until now.I also single step through hardcoded programs.I use the T65 version from fpgaarcade.

http://forum.6502.org/images/migrated/011709-000 ...

Hello all,

this is an amazing work you have done! Thank you so much! Now it is possible for someone who has the skills to write a HDL model of the 6502 that is not only bus cycle exact but also register exact!

I would also like to point you to another project of Mr. Curt Vendel of atariAge:

http ...

Hello all,

the detailed description of this 6502 behaviour here is very interesting but it is not new.
See the fpga64 project at http://www.syntiac.com/fpga64.html
and search for "Fixed IRQ/NMI timing of the branch instructions".
Peter has written an absolutely cycle exact 6510 for the chameleon ...

Hello all,

this is my first post here,so I would like to introduce myself a bit first.My name is Vassilis and I am from Germany.My hobby interests are primary the Atari 8bit computer and the Atari consoles A2600 and VC7800.All of them have a 6502 based CPU.I am exploring a little bit their hardware ...