NES emulator written in D

[Manu]

On Mon, Nov 12, 2018 at 10:30 PM blahness via Digitalmars-d-announce
<digitalmars-d-announce at puremagic.com> wrote:
>
> On Tuesday, 13 November 2018 at 05:59:52 UTC, Manu wrote:
> >
> > Nice work.
> >
> > Oh wow, this is pretty rough!
> > ```
> > void createTable() {
> >   this.table = [
> >     &this.brk, &this.ora, &this.kil, &this.slo, &this.nop,
> > &this.ora,
> > &this.asl, &this.slo, &this.php, &this.ora, &this.asl,
> > &this.aac,
> > &this.nop, &this.ora, &this.asl, &this.slo,
> >     ...
> > ```
> >
> > Here's one I prepared earlier:
> > https://github.com/TurkeyMan/superemu (probably doesn't work
> > with DMD from the last year or 2!) Extensible architecture,
> > supports a bunch of systems.
>
> That's an artifact from the original code which was written in
> Go. My main focus was adding missing instructions & fixing any
> timing issues. It now passes nearly every NES specific CPU
> instruction & timing test I can throw at it so I'm fairly happy
> with it. Any improvements are always welcome though.

A great test is to emulate an Atari2600; you'll know your 6502 is 100%
perfect if you can play pitfall or some other complex 2600 games ;)
I can't see how your cycle counting logic works, it looks like it's
missing a lot of cycles. How do you clock your scanlines against your
CPU?
Can you run Battletoads or Super Mario Bros? They're pretty sensitive
to proper timing.