A Taken branch before NMI delays NMI execution by one full instruction

[HiassofT]

An 800 with the 'old' 6502 (I checked):

 

2206 A9 01 A9 02

2308 A9 02 A9 03

2406 A9 01 A9 02

2507 A9 01 A9 02

Very interesting, thanks a lot again for testing!

 

So it seems that the original NMOS 6502 is also affected by this "interrupt bug".

 

I guess I go over to 6502.org and ask there if someone knows about this.

 

so long & thanks to all of you for your help and ideas,

 

Hias

[Bryan]

I sent a message to Bill Mensch asking him about it. I'll let you know if I get a reply.

[HiassofT]

I sent a message to Bill Mensch asking him about it. I'll let you know if I get a reply.

Great! I'm really curious if he can comment on this :-)

 

BTW: I just started a thread over on 6502.org: http://forum.6502.org/viewtopic.php?t=1634

 

so long,

 

Hias

[bged]

Anyone seen this? I'd love to get my hands on a real simulation model of the 6502.

Thanks for the info, I want one of these too! (and also models for Pokey, Antic, Gtia, of course :-)

 

so long,

 

Hias

That looks fantastic - a visual simulation of 6502 derived directly from photographing deprocessed chips. There's something like a bit like it for the 4004 by Lajos Kintli (Windows executable). See this screenshot:

[Bryan]

Check it out! It's online:

 

http://www.visual6502.org/

[HiassofT]

Check it out! It's online:

 

http://www.visual6502.org/

Absolutely wonderful!

 

I'll start playing with this immediately after I'm done with my work (sigh, still several hours to go...)

 

so long,

 

Hias