Let's Make Robots!

2bit computer

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i am going to make a 2bit computer,it is a simple relay based study project.i will keep updated!


buy parts:
4 pole 12V relay*20
relay socket *20
lots of wires
1 pole switch*10
i think these parts is enough.


received all parts,drawn sch file,the attached picture is version0.1.
it is a very simple full adder machine.because i want to teach my son the binary system,he is only 5years old,at first i do not want make things too complex.the design based on harry's(http://web.cecs.pdx.edu/~harry/Relay/)1bit relay adder.i added I/O system(keep simple,just switch and LED)so we can watch how the machine operation.

the design have not test,i will do it weekend.


2bit relay adder test ok.there are small mistake in the sch v0.1.i updated v1.
i take some photos of the adder's running.see attached.
the below is 10+10=100

the below is 10+11=101

i have design a DTL baesd 1bit adder,this include 9*transistors and 27*diodes.there are nine NAND gates for one bit add.i have build a real thing,no test yet.see below.


i completed the DTL based ALU,and i built two register.

two 4bit register,the bus driver is 74hc244.


finally,i made a simple 4bit cpu.this is a HAND operating cpu.

there are four data input button(gray)and six instruction button(blue) on the panel.five led for result show.

the below is hand made ALU.this block like 74181 chip.

cpu structure show below.

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i'll be tuning in for some updates.

This is exactly something I want to make myself. However, my idea included Transistors and not relays for switching as realys (even digital ones) are not really considered digital technically by a lot of people. However, it'll be awesome to see a relay computer in the making. Best of Luck!!

ya, i am thinking of making one as well...this one soudns cool, an electromechanical computer!

yes DTL machine is fun too.

Do you have the schematics for this!? I was going good on a four bit adder until a wire or two broke and I could not find the problem =)


Good job!

my plan is build a adder first,then add RAM,INT,BUS,so so,step by step.i have updated the first design,hope this running good.

That is a simple circuit! Will you add onto the 2 bit machine when you are finished or will you leave it as a 2 bit computer?

i think you mean 10x10=100 you said 10+10=100

10=2 100=4