I cannot recommend enough Ben Eater's 6502 computer build on YouTube[1] if you want to play with a 6502 computer from the ground up. It is meant to be accessible to the ambitious amateur. It is roughly Apple 1 compatible, and he has videos on how to add new commands in Microsoft BASIC as well as how to modify Microsoft BASIC to support the computer.

Seeing him git clone Microsoft BASIC and make the changes atop it was definitely a weird but awesome moment.[2]

[1] https://youtube.com/playlist?list=PLowKtXNTBypFbtuVMUVXNR0z1...

[2] https://youtu.be/XlbPnihCM0E

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drujensen 6 days ago | parent [-]

100%.

3 years ago I modified his 6502 breadboard project and added a keyboard, display and then I modified MS Basic to get it to run. Also, I found a way to extend the RAM to 31kb. I called it eater-one.

All of his videos and kits are a must if you never understood how a cpu works. I highly recommend them.

https://github.com/drujensen/eater-one

	▲	DrillShopper 5 days ago \| parent [-]
		Another suggestion is Anders Nielsen's channel - his video on a single breadboard 6502 computer (really a 6507) with a RIOT is really good: https://youtu.be/s3t2QMukBRs