Hail!
Once you wrote to Glen McNabb:
 CH> Not quite. NMI is disableable on all 286+ motherboards by setting bit 7 
of
 CH> port 70h. On an XT, It's possible by reprogramming the 8255.
   Wrong. IRQ masking port on XT was 0A0h, 8255 decoded ports 60h thru 63h.
Farewell!
--- GoldED 2.50+
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