\MOVE 1 TO #1005
\ON KEY F10 JUMP MENU
\LOC 0,4\WID 320 DOTS C\HEI 199\OVER 0,A,216
HOW A PISTON ENGINE WORKS
\DRAW C4J0,15R319C,D1C6,D1L319C,D1C5D1R319
\LOC 0,50\WID 214 DOTS\HEI 199\OVER 1,A,9
\IF #775>1\JUMP NOTENUF\ENDIF
\ON ERROR JUMP NOTENUF\READ PISTON.PIC\ON ERROR\MOVE 1 TO #775\JUMP GO_ON
\X NOTENUF\MOVE 4 TO #775\READ SMALLPST.PIC
\X GO_ON
The four-stroke piston engine
was invented in the 1800's.
In 1861 Nikolaus August Otto
built a working four-stroke
gas engine, having realized
the sequence of events
necessary to establish
a continuous operation.
\LOC 0,183\WID 320 DOTS C\OVE 1,A,8
Press "return" to continue...
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\ROUNDS -1 SPEED 14
\SHOW 220,40,1,24
\X NEXT1\ON KEY 7181
\LOC 0,30\WID 200 DOTS\HEI 199\OVER 1,A,7\SHOW 220,40,2
First, an air-and-fuel
mixture is introduced
into the chamber (in the
drawing at the right,
represented by the blue
dots.)  The valve on the
right (red in the
illustration) opens as the
piston sucks the mixture in.
When the piston is at the
bottom of its stroke the
valve is closed.
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\ROUNDS 1 SPEED 112
\SHOW 220,40,2,7
\X NEXT3\ON KEY 7181
\LOC 0,30\WID 200 DOTS\HEI 199\OVER 1,A,5
\"
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Next the gas mixture is
compressed to a small
fraction of its normal
atmospheric volume.
\"
\"
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\WAIT RET -1
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\SHOW 220,40,8,11\SHOW W=0,65,320,199 F=12,12
\IF #775>1\SHOW W=0,52,320,200 F=13,13\ELSE\SHOW W=0,070,320,199 F=13,13\ENDIF
\X NEXT4\ON KEY 7181
\LOC 0,60\WID 200 DOTS\HEI 139\OVER 1,A,7
As the piston reaches
maximum compression a
spark is introduced,
and the resulting
explosion forces the
piston down.  This is
the power stroke of the
engine.
\WAIT RET -1
\ON KEY 7181 JUMP NEXT5
\CLEAR SHOW
\SHOW 220,40,13,19
\X NEXT5\ON KEY 7181
\LOC 0,60\WID 200 DOTS\HEI 139\OVER 1,A,4
\"
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After the power stroke,
the exhaust valve opens so
that the rapidly cooling
gases can be expelled
from the cylinder.
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\WAIT RET -1
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\SHOW 220,40,20,24
\X NEXT7\ON KEY 7181
\LOC 0,81\WID 200 DOTS\HEI 199\OVER 1,A,3
The exhaust valve closes
and the intake valve
opens as the cycle begins
to repeat...
\"
\WAIT RET -1
\ROUNDS -1 SPEED 84
\LOC 0,183\WID 320 DOTS C\OVE 0,A,13
Press "return" to go to the main menu...
\ON KEY 7181 JUMP MENU
\SHOW 220,40,1,24
\X MENU\CLEAR SHOW\READ MENU.TXT
