Video/Pin conventions for extra lives

On Wed, 22 Dec 1999 mike_ranger@DOFASCO.CA wrote:
>
> And, although probably common knowledge, when you get an extra ship,
> it let's you go again, which I can only assume it is it let the players
> finish together. If the one player (Paul) is much better than the other
> (Mike), Mike get's to stay, and play until the end, rather than potentially
> getting up to play another game while Paul finishes. A revenue tactic me
> thinks!

More of a counter-revenue tactic, if you're an operator :) On the other
hand, it's rather interesting that Omega Race follows the "pinball"
convention of letting you play your "extra ball" with your original
ball, where most vids alternated player 1 and 2 regardless of how many
extra ships were awarded.

As a handwaving guess as to why pins and vids evolved different
conventions for multiplayer behavior upon award of an extra ball/life,
here's my speculation:

I suspect the "video" convention of alternating player 1 and 2 was because
it was easier to do in software - Asteroids, for instance, used the same
RAM addresses for player 1 and 2, and bank-switched the game state every
time the player changed. They even used the same control inputs on the
cocktail cabinet, switching the inactive panel off by means of a signal
("PLAYER1" or its inverse) and a couple of diodes in the wiring harness.
With most vids being 2-player, rather than 4-player like pins, a 1-bit
toggle from player-1 to not-player-1 every time someone got killed was
probably easier to code, plus there were thousands of addresses in RAM
that could be used for counters to store the number of ships in reserve.

With pins having descended from state machines where little, if any, data
was stored in "memory" between plays (i.e. your score wasn't stored
anywhere in the electromechanicals except in the positions of the wheels
in the backglass :), it was probably easier to wire in "if after ball
drains, extraball was awarded, return to ball-at-plunger state, else [no
extraball was awarded] switch to next active player's score display,
before returning to ball-at-plunger state". (Implementing the "video"
convention would require that the pinball machine somehow record a
separate "number of balls remaining for each player" counter somewhere, as
opposed to the global "ball in play" display that applied to all players
at once. An EM pin doesn't know what your score is or how many balls you
play, as long as it can increment the score by the value of each target,
and end the game when the "ball in play" counter rolls over at "5",
regardless of how many extra balls were awarded between ball 1 and 5.)

Later,
Doug.

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