Homebrew 16 bit relay computer

A new video is online, in this video I describe how logic using relays works and how the registers are designed...

So, the first module, the address calculation module, is now finished...I added a plug to connect it with the control unit.

The wiring of the system is a bit messy, as can be seen in the following image:

So, I disconected the modules...

I will rewire the system, and I will use the following connectors for this purpose:

A major success has been achieved...the system test, which thoroughly tests all components of the system, was successfully completed. The following video shows the execution of the test. Phase 1 is now complete, and in Phase 2, the system will be extended with input and output registers.

To be sure that the system is working fine, development of a system test software ist started...the software will test:

a) all CPU-commands

b) the ALU

c) the adress range

The first step is a dynamic generation of a jump table with the subroutines for the three tests and a collection of the results.

So, the durability test is now finished. Thats the circuit diagram of the test:

Thats how the test looks like in reality:

The following picture shows the the Osci-Output (yellow: Arduino, blue: the second relay)

Anf here is the protocol:

So, more than 20 million switches are finished without problems...perfect accordance with the datasheets:

To ensure that repeated test runs of the system do not lead to a relay failure (relays are mechanical components and do not have unlimited durability), I have now started a durability test of two relays. An Arduino switches on and off 50 times per second, using a transistor to control a relay. This relay, in turn, switches a second one. I will let this setup run until one of the relays fails.

I tried a new program. I wanted to multiply 3 pairs of numbers and add the results...perfect for using the CALL and RETURN functions. But the end-result was not correct. I analyzed videos of the runs (by checking the LEDs), I also tried the three multiplications and the addition of three results in seperate programs...everything was fine. I think that the three multiplications are influencing each other...but before I step deeper into the problem I write a program which is testing the complete hardware of the system, especially the ALU, to be sure that a program error is the reason of the little problem.

So, the new commands are working fine, but the wiring is a little bit crazy:

The new board you see is the register which is able to store the return address.

Last week I finished two boards for the CALL and the RETURN command. The CALL command stores the program counter into a register and jumps to the adress after the CALL command, the RETURN command copies the adress stored in the this register into the program-counter.