3 ms·

Given that the NES had NMI and the 2600 didn't, I think that NMI probably should have been wired to horizontal blank to begin with. I'm sure that there is some

Given that the NES had NMI and the 2600 didn't, I think that NMI probably should have been wired to horizontal blank to begin with. I'm sure that there is some reason why this wasn't done, but I can't understand why.

jdsully 7y ago
That would have wasted precious cycles for games that didn’t need it. The ‘n’ in NMI stands for non-maskable.
- bonzini 7y ago
  You can always mask it (enable/disable) at the place that triggers the NMI.
  - jdsully 7y ago
    Adding a a gate with jellybean logic was a noticeable expense in the 80s and would still be today.