Make a One Chip RAM (random Access Memory)




Introduction: Make a One Chip RAM (random Access Memory)

Hi,since this is my first instructable and English is not my mother language so please excuse me for mistakes.

This instructable I'm going to show you how to make a RAM to use with a micro-controller for storing data and it is also expandable and uses only one IC and no other components. It is easy for any hobbyist to make.(COMMENT PLEASE) on to the next step!

Step 1: The Chip

The chip is a ten bit decade counter the "4017" but we only use two bits. You will make only six connections. Here is the data sheet of the chip. (COMMENT PLEASE) On to the next step!

Step 2: The Schematic

Wire every thing as the schematic.(COMMENT PLEASE)

Step 3: Using It

To use it on a micro-controller (for example arduino or pic )the read pin is connected to digital pin on the controller and the digital pin is set as an input. The write pin is connected to a digital pin that is set as an output. The write enable is connected to a digital pin that is set to output. When the chip is turned on for the first time the read pin is high. To write pull the write enable pin low then if the read pin is high a pulse will make it low if it was low a pulse will make it high. (what i mean here by pulse is pulse going to the write pin). If you don't want to use it with a micro-controller then connect a 4.7kohm resistor between power an write enable pin.(COMMENT PLEASE)

Step 4: Expanding

To add more bits or if you go large bytes (1 byte = 8 bits) duplicate the circuit as many bits as you want and then connect all the write enable pins together. That is it hope to see you again PLEASE ADD COMMENTS AND SUGGESTIONS AND CORRECT ME IF I WAS WRONG thank you.

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    1 year ago

    Can this be connected and work on a computer? And how much ram is those 3 connected?


    3 years ago on Step 2

    Perfect for everyone. Thank you a lot.


    6 years ago

    Great Instructable! But I have a problem, how can I use an SD card as RAM for a microcontroller? I cant find the chip you used anywhere! PLZ HELP


    Reply 5 years ago

    Thank you!

    An SD card shouldn't be used for RAM as it's slow and has limited number of read and write cycles that is less than a typical ram chip by a few orders of magnitude, so it's life as a ram would be extremely short. Check this out