Johnny's home-built CPU corner (and other stuff, maybe)


8080 CPU, built entirely by DTL-technology

Microcode SRAM


There isn't much to say about this. 8 pcs of 32Kx8 SRAM.  64 bit wide microcode.  The left one is dedicated for the ALU and the one to the right is for REGISTERS.


As you can see I have made 2 boards. Why not just one?

The CONTROL logic is somewhat complicated and thanks to the use of discrete components elsewhere it will take some room to fit it all together.

To that end I made the (easy) decision to go for 2 boards, each is 233x160 mm.


The Microcode Loader, the Microcode Sequencer and the IR register are all placed on the right side. The bottom right connector is for communication to those other boards.


Besides the SRAM chips there is 10 pcs of 74HC595 but they are not part of the 8080, they are only there for the purpose of loading the microcode into the SRAM.


The SRAM chips are the only (!) IC that is part of the actual 8080.


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