Doom does not run on 64 bytes of RAM.

Original system regs were 8 MB RAM. You can run it on 4 MB and can shave off some more but you need 16-bit bus ~MB's of RAM to run it.

I believe that's if you're running it under Windows, I feel sure I was playing Doom on DOS with 4mb ram.

Edit: yep, https://oldpcgaming.net/doom-1-review/

Yes. I remember that too. I edited it to 4 mb just before you responded.

The point is you can't run doom on hundreds of bytes or even several kilobytes or in 8 bit microcontroller.

Indeed, I didn't need to nitpick