DavidMil Posted May 23, 2021 Share Posted May 23, 2021 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 1 Quote Link to comment Share on other sites More sharing options...
atarialoha Posted May 23, 2021 Share Posted May 23, 2021 The Monster 6502 is impressive work. Also, if you haven't yet watched this video, I highly recommend it. 4 Quote Link to comment Share on other sites More sharing options...
atarialoha Posted May 23, 2021 Share Posted May 23, 2021 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. Quote Link to comment Share on other sites More sharing options...
zbyti Posted May 23, 2021 Share Posted May 23, 2021 (edited) Nice idea! :] Edited May 23, 2021 by zbyti Quote Link to comment Share on other sites More sharing options...
+DjayBee Posted May 23, 2021 Share Posted May 23, 2021 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? Quote Link to comment Share on other sites More sharing options...
xxl Posted May 23, 2021 Share Posted May 23, 2021 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 Quote Link to comment Share on other sites More sharing options...
Keatah Posted May 23, 2021 Share Posted May 23, 2021 My i9 does this. Hit the F1 key and suddenly we're playing Miniature Golf at thousands of FPS. Quote Link to comment Share on other sites More sharing options...
atarialoha Posted May 23, 2021 Share Posted May 23, 2021 Ha! Finally found one https://opencores.org/projects/cpu6502_true_cycle Quote Link to comment Share on other sites More sharing options...
dmsc Posted May 24, 2021 Share Posted May 24, 2021 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! 1 Quote Link to comment Share on other sites More sharing options...
atarialoha Posted May 24, 2021 Share Posted May 24, 2021 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. Quote Link to comment Share on other sites More sharing options...
JKK Posted May 24, 2021 Share Posted May 24, 2021 Amazing project! Btw, it would be probably impossible to make replica of any of currently used processors. It would be really huge... Quote Link to comment Share on other sites More sharing options...
+slx Posted May 27, 2021 Share Posted May 27, 2021 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. 1 Quote Link to comment Share on other sites More sharing options...
ivop Posted May 27, 2021 Share Posted May 27, 2021 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. 1 Quote Link to comment Share on other sites More sharing options...
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