News for hackers. Stuff that matters.

A comment on DLS, the digital logic simulator game.

Re:DLS, the digital logic simulator game by userbinator on Saturday August 06, 2016 @02:24PM (#12239226)
One of my criteria for assessing a logic simulator is whether it can simulate something nontrivial like an entire CPU, so I was pleased to see there's a 6502 here...

https://github.com/jdryg/dls-schematics/tree/master/6502

...but it seems to be only a 6502-based system showing that you can use a 6502 as an opaque component, and isn't actually simulating its logic with the siulator. On the other hand, the 4004 here is mostly the real deal:

https://github.com/jdryg/dls-schematics/tree/master/i4004

[ Parent | on HN ]
Re:DLS, the digital logic simulator game by jdryg on Sunday August 07, 2016 @02:57AM (#12241334)
The i4004 was the first real thing I tried to simulate in DLS (I thought it would be easy since it's only a 4-bit CPU... :)). As you said, it's mostly the real deal, since it's missing some components. That's why I added scripting to see if it can make the whole process a bit simpler.

When scripting was implemented, I didn't want to redo the i4004, that's why I started the 6502. And since kernel and basic ROMs were available online, I thought of adding a display to see if I can get some output.

AFAICT, building an entire CPU out of logic gates in DLS is feasible. I just don't have all the time required to do it, that's why I'm currently building (reusable?) parts of a CPU and document the process in the blog. It will be complete some day, but not anytime soon :)

[ Parent | on HN ]