I'm designing a new trading board game that replaces the paper money tokens with a swipe card system that stores each player id and credit balance and during the course of the game will deduct and credit their points/cash.

I have looked at the commercial versions used with a computer. But I need something less expensive and complicated. Basically I'm looking for a glorified electonic calculator with memory that can write and read 6 players scores. I like the idea that each player would have a swipe card and they can use the card to trade during the game.

The reader/writer would also have a calculator to add credit or take away from the player balance.

Also some other functions that deduct or add set amounts.

Therefore a stand alone reader/writer with memory and LED calculator powered by a battery or mains adaptor. I'm looking to keep the unit as cost effective and wonder is there anyone have ideas where I can start to design and build the electronics of the unit.

I was hoping to store the balance on the magnetic strip of a plastic card but this wont be necessary as the swipe card will only need to act as a key to each player. The memory chip would store the results of the each player and display via the LED.

I am talking about a very basic electronic hard and software maybe I could modify a cheap calculator.

Maybe the swipe card could have just 1 to 6 holes instead of a magnetic strip. The card is only a key to the individual player.

Any ideas would be appreciated.