This might of interest - it's a graphical application that runs on Windows, OS X, Linux.

https://github.com/hneemann/Digital
(Screenshots within.)



Looks like it can optimise logic, and output TTL-style circuits or HDL for programmable logic. And the simulation sounds pretty fast and flexible.

Interesting that it can also include VHDL and Verilog components in its simulation. Theoretically that should mean you can include your choice of CPU to virtually build your computer around. And then with a custom Java component you can simulate your I/O devices, like a graphics or soundcard.

Ah, I didn't spot that - it is indeed interesting.

This is supposed to be a replacement of logisim, with really interesting new features.
But I tried the Mac version of it, and to me it was unusable. I wonder if the Windows version works better. The problem I had, is that when I move components around, wires connected to them do not move or follow the components. Therefore rewiring is required every time I need to arrange components in a different way or just move them to make room for more. It makes me think that I am missing something really obvious, because that's totally ridiculous, but whatever I tried the issue is always there (!?)

It does work as intended, and now i am thinking to make the 6502 purely on logic

This is normal

everything you select will move, so if you only grab the component all the wires stay in place, you actually have to make a selection box around the component that also grabs the adjacent wires for them to move with everything else.
note that Digital treats wires as 2 seperate points with a graphical line drawn between them.
So if you only select 1 point of a wire the other side will stay in place, but if you select the whole wire then it will move the whole wire without distorting it.

it's a bit weird to get used to from Logisim's automatic rewiring, but i think i prefer it over Logisim making huge U turns over other wires and components that i then have to manually remove.
I still use both programs very regularly.