Jasen,
Old and oldfashioned but great fun. Although I have to admit I don't see how
to connect that bistables to achieve a fair 1:6 chance for every throw. Ever
had the idea to go and collect dice circuits. Guess I'd need a big, big
harddrive for it. FAIK the latest dice can be made by a small micro, the
PIC12F629 or a similar tiny AVR.
petrus bitbyter
Bistable one was wired to change state with every clock pulse
it drove the dot "1" with its Q output and was wired with its
~Q output to the set input of of the second bistable, and a
high-pass filters to the set inputs of the other two bistables.
The second bistable drove the dots labeled "2" and "3" with with its
Q output and it's ~Q output was wired to the reset input of the third
bistable via a low pass filter.
the third bistable drove the dots "4" and "5" with its Q output and like
the second bistable it's ~Q output was wired to the reset input of tjh next
bistablee, the fourth.
the fourth bistable drove the dots with it's Q output
and also with its Q output drove the reset input of the second astable
but via a resistor so that it wouldn't reset while it's set input was high.
this was how it worked 2 6 4
1
5 7 3
start
bistable 1 set this lights dot 1
all the others reset, no other dota alight display shows "1"
clock pulse.
bistable one switches, dot 1 goes out,
bistable 2 gets set signal so dots "2" light,
bistable 3 and 4 also get brief set pulses but as their reset inputs are
activated via low pass filters from bistable 2 and 3 respectively the don't
change state (they may glitch a little but it doesn't show).
so the dots "2" and "3" are lit - the display reads "2"
clock pulse,
bistable one switches, dot 1 lights,
set input to bistable 2 goes low (no effect) negative pulses on the set
inputs of bistabl 3 and 4 (no effct)
so the so dots "1","2" and "3" are lit - the display reads "3"
clock pulse.
bistable one switches, dot 1 goes out,
bistable 2 gets set signal (it's already set) no effect
bistable 3 gets the set pulse as bistable two is already set there's no
reset signal present so it changes state, dot's "4" and "5" light.
bistable 4 gets the set pulse but is reset via the low pass filter from
bistable 2 (so no change)
so the so dots 2,3,4,5 are lit - the display reads "4"
clock pulse.
bistable one switches, dot 1 lights,
set input to bistable 2 goes low (no effect) negative pulses on the set
inputs of bistabl 3 and 4 (no effct)
so the so dots 1,2,3,4,5 are lit - the display reads "5"
clock pulse.
bistable one switches, dot 1 goes out,
bistable 2 gets set signal (it's already set) no effect
bistable 3 gets the set pulse (it's already set) no effect
bistable 4 gets the set pulse as bistable 3 is already set there's no
reset signal present so it changes state, dot's "6" and "7" light.
bistable 2 gets the weak reset signal but as there's a set signal present
doesn't reset
so the so dots 2,3,4,5,6,7 are lit - the display reads "4"
clock pulse.
bistable one switches, dot 1 lights, the set input to bistable 2 goes low
the reset input (from bistable 4s output) resets bistable 2 now that the
set input is low bistable 2 changes state. dots 2 and 3 go out, bistable
2's ~Q output goes high,
the high on bistable 2's ~Q output passes through the low pass filter and
resets bistable 3, bistable 3 changes state. dots 4 and 5 go out, bistable
3's ~Q output goes high,
the high on bistable 3's ~Q output passes through the low pass filter and
resets bistable 4, bistable 3 changes state. dots 6 and 7 go out, the
reset signal to bistable 2 turns off.
so dot 1 is lit, and the display reads "1" again.
this is the state I started with.
I'm not sure of the exact details of the conection to bistable 2's reset
input. there may have also been a primitive diode-resistor "and" gate
combining bistable 4's Q output and bistable 1's ~Q output instad of
the resistor I describe above...
Bye.
Jasen
