OK/Red Letter Game - Green Score Unit
Red Lamps In Game Name
The green score unit disc drives a couple things. The most obvious is lighting the correct letter in the game name red to indicate the ok/red letter game level. At any given moment, one letter in the game name is lit red, and the rest are lit white.
The circuit itself is a little odd because it relies on the physical properties of the lamps used. For the game name letters that need to be white, both the red #55 lamp and the white #47 lamp are connected in series between the two power supply rails. The current flowing through both lamps is sufficient to light the white lamp, but not enough to cause the red lamp to glow (much). Hence the game name letter appears white.
For the game name letter we want lit red (e.g. 'O' in the green highlighted circuit), the green score unit shorts out the white lamp so only the red lamp is connected between the power supply rails. Since this single lamp has less resistance than both lamps in series, more current flows and it's enough to cause the red lamp to glow brightly.
This reliance on the properties of the lamps means you must use different lamp types for the red and white bulbs. If you tried to use the same type lamp for both the red and white bulbs, they would glow equally dimly for the game name letters that are supposed to be white and you'd get one red letter and five pink ones.
Controlling Reset When Collecting OK/Red Letter Win
One big image for one simple concept. All the green score unit does is direct a pulse stream entering it on wire #56-3 out onto the wire corresponding to the lit ok/red letter.
For our example of the red letter being "O", the green highlighted circuit shows the green score unit connecting wires #56-3 and #63-17, which connects the pulse stream to wiper D on the ok/red letter unit.
For whatever reason, the wiper feed labeling on the ok/red letter unit isn't the obvious ABCDEF for BOUNTY, but is instead interleaved as shown on the image.
All the magic happens on the ok/red letter unit. Before looking at that, though, let's see where the pulse stream is coming from and where it's going.
