Universal 8116 daughter board 8116-SDS3 or 8116-SW1(B-D)

[uniman]

A little history lesson will help to understand the 8116 board.
When Universal came out with the 8116 board their slots had no buttons for credit, max bet, bet one, and cashout. You pulled the handle and all wins up to payout limit were paid immediately by the hopper.
When the buttons were added Universal also added the two molex connectors you see coming out of the MPU case to connect to the buttons and added a daughter board to eprom location A1. The first daughter board was the 8116-SW1(B-D). This little board has an 8-dip switch that determines credit limit, hopper type, and in some cases credit only/credit selectable choice. Then when casinos began connecting machines to their monitoring system they expanded this little board to include outputs to the casino's monitoring system. This was the 8116-SDS3.
Universal could have made eproms to do the same job as the 8116-SW1(B-D). But the dip switches allow changes to be made without changing eproms. Much easier. (Not to mention the cost of getting gaming commission approval of each eprom)
For the home user either daughter board will work. Without this board the machine will malfunction with varying errors depending on game and machine eproms used. These errors are usually;
31 - Hopper overpay
32 - Coin out jam
33 - Hopper empty
21 - coin-in jam
12- RAM error
and hopper runaway.

There is another little board called the 8116 SUB. This board is on most all 8116 boards and is used for transmitting coin-in and jackpot pulses to a progressive system.

[mantaramian]

A little history lesson will help to understand the 8116 board.
When Universal came out with the 8116 board their slots had no buttons for credit, max bet, bet one, and cashout. You pulled the handle and all wins up to payout limit were paid immediately by the hopper.
When the buttons were added Universal also added the two molex connectors you see coming out of the MPU case to connect to the buttons and added a daughter board to eprom location A1. The first daughter board was the 8116-SW1(B-D). This little board has an 8-dip switch that determines credit limit, hopper type, and in some cases credit only/credit selectable choice. Then when casinos began connecting machines to their monitoring system they expanded this little board to include outputs to the casino's monitoring system. This was the 8116-SDS3.
Universal could have made eproms to do the same job as the 8116-SW1(B-D). But the dip switches allow changes to be made without changing eproms. Much easier. (Not to mention the cost of getting gaming commission approval of each eprom)
For the home user either daughter board will work. Without this board the machine will malfunction with varying errors depending on game and machine eproms used. These errors are usually;
31 - Hopper overpay
32 - Coin out jam
33 - Hopper empty
21 - coin-in jam
12- RAM error
and hopper runaway.

There is another little board called the 8116 SUB. This board is on most all 8116 boards and is used for transmitting coin-in and jackpot pulses to a progressive system.

Is the "little board called the 8116 SUB." necessary?

[uniman]

Is the "little board called the 8116 SUB." necessary?

Yes, and sometimes no. 

Yes it is needed to determine hopper type and set credit limits. Also used to determine type of optics being used as earlier Universal's had black optics. And can be used to set all wins go to credit or all wins get paid out immediatley.

You see Universal's first machines had no credit meter, no spin buttons, and all wins were immediatley paid out by the hopper. Then buttons were added and that's why there are two sets of wires coming out of the 8116 to two connectors. They operate the buttons and were added to the board. Then the credit meter and two types of hoppers were used, the regular hopper with a coin counting switch and the high speed plastic hopper with coin counting optics. So the sub board was added. By setting the dips on the sub board you are telling the machine what hopper it has.

And now for the sometimes no; The sub board plugs into an eprom socket and the dips act like an eprom. The game's program fetches a binary 0 or 1 from the dips. I was able (a fews years back) to program a 2732 eprom and it worked in place of the sub board. As I remember the OFF on the dip was a binary 1 and the ON was a binary 0.

The first sub board was small and was used only for the above mentioned. Later they created the bigger sub board for communicating to a casino monitoring system besides the aboved mentioned.

The manual says it is needed for type 2 games but not for type 1. I think type 1's are rare as I have not seen one or recognized one.

Often without the sub board the hopper fails to payout correctly and you get errors for overpay, etc.