Show HN: Turbine – 16-bit CPU Architecture and Emulator built in C
12 comments
·June 20, 2025lioeters
Fun article and project. I enjoyed reading and playing around with it.
My first run of `make release` failed with this error.
cc -std=c11 -Wall -Wextra -Werror -pedantic -O3 -DNDEBUG -c -o build/main.o src/main.c
src/main.c: In function ‘main’:
src/main.c:23:3: error: ignoring return value of ‘fread’ declared with attribute ‘warn_unused_result’ [-Werror=unused-result]
23 | fread(file, file_size, 1, fp);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
errorcodezero
Ah oops small mistake with the C file handling. Thank you for the kind words on my project and finding the issue I'll be sure to fix it when I get the time.
lioeters
The article was really good, explaining the details of how the virtual machine works.
I starred the Git repo, good luck with the Hack Club!
errorcodezero
Thank you for the star. It means a lot that you found the stuff I make cool.
johnisgood
Yes, to fix it: either check its return value, or add "(void)" at the end of the function, e.g. "(void)fread(...)". Since they did not add "(void)", I assume they meant to check the return value, they just simply forgot.
drob518
Fun project. You might want to build an emulator for a real 16-bit CPU like a 6502. That would allow you to run real, existing software on it. That way you don’t have to write your own code.
AlexeyBrin
6502 is an 8-bit CPU. Writing an emulator for it would be cool though.
vardump
It's interesting how arbitrarily CPU bitness is defined. Sometimes it's the register size, sometimes data bus width and sometimes the address width.
6502 has 8 bit registers, 8 bits wide data bus, and 16 bit addresses. Only PC register is 16-bit, but 6502 does have a zero page indirect 16-bit addressing mode.
wang_li
Sometimes by register size, sometimes by ALU size, sometimes by data bus width. But I've never heard of a CPU bitness defined by address bus size.
pjc50
M68k is probably the best choice for that. Not because of the architecture but because it was so widely used.
dmitrygr
68k has too many addressing modes. It is a pain to emulate properly.
errorcodezero
Thank you! I think building an emulator for a real platform is going to be next on my list. A game console might be interesting to try especially or a 16-bit cpu like you mentioned.
Github: https://github.com/errorcodezero/turbine