I recently e-mailed Mike and asked if my emulator was worthy to be added to the 6502.org's emulators section.
He agreed and it is now added.
This is when I found this topic.
I wish I checked the forum more often.
Perhaps I will try it as New Year's resolution :-)
One has got to be up to date with ...

This is brilliant!

I built version 1.3.0-SNAPSHOT and fired up EhBASIC.
Nice GUI. It will be a valuable tool for any MOS 6502 enthusiast.
I did full MOS 6502 op-codes implementation in C++, including BCD mode: https://github.com/makarcz/vm6502
My emulator is nowhere as advanced as yours, just ...

Nice.
I'm doing something similar, project in progress, 6502 emulation, possibly something more in the future.
Rudimentary character I/O is supported.
Blog entry:
http://leisureprogramming.blogspot.com/2016/02/virtual-machines-and-cpu-emulation.html
Code:
https://github.com/makarcz/vm6502
I ...

The stupidest thing caused the RTC problem on CPU bus - the connection issue.
I have been connecting the RTC circuit built on the breadboard to my mobo with cables to slot B2 on the CPU bus. That particular slot had a connection
issue on pin A25 (data pin D3) - which simply did not have an ...

Jeff, you're correct. No multiplexer. Instead, the address/data are provided by hardware/software combined emulation in 2 steps.
The 74LS138 decoder with its address selection lines connected to pins Phi2, R/W and A0 depending on what's happening on the bus will select output pins that drive DS1685 ...

Hi guys,

I hope you can advise me on a problem I am having with my design.

My 6502 based general-purpose system is build around a mother board with 2-sided bus, which has a CPU side and buffered I/O side, both separated with 74LS245 transceivers.
I gate the buffer that separates data lines with ...

Congratulations are in order.

Lastly, thanks for the tip about starting small. I actually found myself thinking about grand stuff like a keyboard interface and some sort of display before I realized that the first step should be a 65c02, a chip for serial access over a terminal, some memory, and whatever glue chips. If that ...

Welcome Bogogil,

That "Kiwi" is a great piece of engineering. I saw it before on YouTube.

Good to have you here.

Hi alkopop79,

Just dropped in to 6502.org after a long break and notice this thread.
You were looking for some basic diagram of 6502 CPU system?
I got inspired by this project: http://chidesters.org/scott/meadow/Meadow_6502_SBC_User_Doc.html
It is a complete minimal 6502 computer with operating ...

Hello,

I recently re-discovered my own FORTH stuff for Commodore 64. I used to program a little in this beautiful system/language and now I want to pick up where I ended 15 years ago and extend my system a bit further (I did in FORTH a 7-segment display driver, 12-hour screen clock running in ...

Update:
I am reading the article about differences between PAL and NTSC video systems in context of C64 software and hardware compatibility and it looks like I should probably save $$ and not to buy a new VIC chip. Appears to be a normal thing for some software titles to have problems, when designed ...

Well, my PLA repair is based on EPROM, the chip is marked ST 27C512 and it matches the description about typical PLA repairs done with these chips, that I found on the internet.
Anyway, I am a little disappointed, because my PLA arrived in mail today, I replaced it and C64 still acts up the same ...

Thank you guys for all the replies. Very helpful.
I did find the 27C512 EPROM to PLA adapter schematics. I checked connections in the adapter found in my C64. All were OK. I replaced old IC socket with the new, better quality one with round pins. I re-did the adapter in fact. I soldered the EPROM IC ...

Thanks a lot for looking, Garth! I really appreciate it!

Well, if you find some time in the future and it would not be too much trouble, please send me a list of apple II related materials that you have. Perhaps I can pick something useful and we would agree to the price/shipment. Once again, thank ...