Jump to content
DavidMil

The 6502 Processor.

Recommended Posts

Many years ago (my wife is looking over my should and asked if this was going to be one of my caveman stories).  No Dear,

not that many years...  I wanted to build a 6502 processor using through-hole components.  I gave that up when a little research

pointed out that I would need approximately 4478 additional transistors to go with the 50 that I had, and 1019 resistors.  What

brought all this on was when I came across this interesting site:

 

www.monster6502.com

 

And it reminded me of that old idea I had.  (My wife is laughing now, but she's asking how come I can remember something

from 35 years ago, and can't remember what she asked me to do yesterday!  I'm now playing confused...).  Reading down

in the article, I noticed that to use through-hole components I would need a surface area of over a square meter.  Anyway

this is an interesting article.

 

DavidMil

 

    

  • Like 1

Share this post


Link to post
Share on other sites

The Monster 6502 is impressive work.

 

Also, if you haven't yet watched this video, I highly recommend it.

 

 

  • Like 4

Share this post


Link to post
Share on other sites

On a related note, I have yet to find an open source 6502 core to be used in FPGAs so we can run it at 100 MHz or higher.

 

I keep seeing mention of such things but never can seem to find such a virtual core to download.

Share this post


Link to post
Share on other sites
1 hour ago, atarialoha said:

On a related note, I have yet to find an open source 6502 core to be used in FPGAs so we can run it at 100 MHz or higher.

 

I keep seeing mention of such things but never can seem to find such a virtual core to download.

Have you asked foft?

Share this post


Link to post
Share on other sites
1 hour ago, atarialoha said:

On a related note, I have yet to find an open source 6502 core to be used in FPGAs so we can run it at 100 MHz or higher.

Eclaire does this, you can set the clock of the 6502 in bios

Share this post


Link to post
Share on other sites

My i9 does this. Hit the F1 key and suddenly we're playing Miniature Golf at thousands of FPS.

 

Share this post


Link to post
Share on other sites

Hi!

19 hours ago, atarialoha said:

On a related note, I have yet to find an open source 6502 core to be used in FPGAs so we can run it at 100 MHz or higher.

 

I keep seeing mention of such things but never can seem to find such a virtual core to download.

There are a lot of 6502 cores, in Verilog and in VHDL. Two of my recommendations:

 

- The Atari 800 core by Foft uses the VHDL core from the FPGA-64 by Peter Wendrich, see http://www.64kib.com/atarixlfpga_svn/trunk/atari_800xl/common/a8core/cpu_65xx_a.vhd

- If you want a really simple and small core, in Verilog, the one by Arlet Ottens is great:  https://github.com/Arlet/verilog-6502

 

A great place to discuss about reimplementations of the 6502 is the 6502.org forum, at http://forum.6502.org/viewforum.php?f=11  There you can find TTL implementations that work replacing the original CPU, and fast TTL implementations at more than 20MHz, with full cycle accuracy.

 

Have Fun!

  • Like 1

Share this post


Link to post
Share on other sites
7 hours ago, dmsc said:

Hi!

There are a lot of 6502 cores, in Verilog and in VHDL. Two of my recommendations:

 

- The Atari 800 core by Foft uses the VHDL core from the FPGA-64 by Peter Wendrich, see http://www.64kib.com/atarixlfpga_svn/trunk/atari_800xl/common/a8core/cpu_65xx_a.vhd

- If you want a really simple and small core, in Verilog, the one by Arlet Ottens is great:  https://github.com/Arlet/verilog-6502

 

A great place to discuss about reimplementations of the 6502 is the 6502.org forum, at http://forum.6502.org/viewforum.php?f=11  There you can find TTL implementations that work replacing the original CPU, and fast TTL implementations at more than 20MHz, with full cycle accuracy.

 

Have Fun!

Thanks! This is wonderful! I am only just starting to get into FPGAs.

Share this post


Link to post
Share on other sites

Amazing project!

 

Btw, it would be probably impossible to make replica of any of currently used processors. It would be really huge...

Share this post


Link to post
Share on other sites
31 minutes ago, JKK said:

Btw, it would be probably impossible to make replica of any of currently used processors. It would be really huge...

Apart from the space required the size would probably cause signal latency issues as well.

  • Like 1

Share this post


Link to post
Share on other sites
4 minutes ago, slx said:

Apart from the space required the size would probably cause signal latency issues as well.

Yes. Maximum reliable clockrate for the monster6502 is 50kHz.

 

  • Like 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...