PAL16R8
BRUCE CULBERTSON   4 OCT 1987
PAL TO GENERATE ONE CYCLE NMI PULSE WHEN SWITCH IS PRESSED.  IS THIS REALLY
NECESSARY?  DATA SHEET IS AMBIGUOUS: IS NMI LEVEL OR EDGE SENSITIVE?
CLK	/UP	/DOWN	/TSO	NC	NC	NC	NC	NC	GND
/OE	/NMI	/DUMMY	/DELTSO	NC	NC	NC	NC	NC	VCC

           ; ON IF SWITCH PRESSED, NOT ALREADY ON, AND DUMMY NOT ON
NMI	:= DOWN * /NMI * /DUMMY

DUMMY	:= NMI +              ; GOES ON ONE CYCLE AFTER NMI
           DUMMY * /UP        ; IF ON, STAYS ON UNTIL SWITCH OPEN

           ; DELTA TSO (DELAYED ONE CLOCK)
DELTSO  := TSO