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65816 First Fire Up - No Magic Smoke

Updated: Feb 11, 2022

Well, I have applied power. Magic smoke not detected. I haven't yet reviewed the monitored data to see if it matches what is expected at this point in the build.


After posting the video above, I realized I grabbed the wrong inverter from my parts bin. I have swapped out the inverter with a faster one.


Postscript

I now have the decode logic circuit connected -- and it appears to be working. The following oscilloscope output is looking at the enable lines for ROM and RAM while the 65816 is running.

OE for ROM and RAM
OE for ROM and RAM

Below is the state of the build for the above output. Next, I need to connect the output of the FPGA to the 3.3V-to-5V level shifter. After that, I can connect ROM and RAM to the address, data, and OE lines. Then... I might get to try some 65816 assembly.

Build with initial decode logic running
Build with initial decode logic running
Corresponding schematic
Corresponding schematic


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Joe Plocki
Joe Plocki
24. Jan. 2022

I may register here from my home PC with my personal account, just so I can post a pic of my own similar effort from the first half of this weekend. I hope you got what you expect - I didn't. But after I analyzed it long enough, what I got is what I expect from monitoring the lines on the board. Address bus, I got that right. Data bus... it feels like my '245 is backwards, but rereading the datasheet a dozen times, it should be right. Right now, I've been at the pool hall all day, and there's beer and its side effects, so I probably won't mess with it tonight. With my 245 feeding FF …

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