I still have a couple of TRS-80 computers (a model I and a model III) with Z-80 chips (and a Qume daisy wheel printer). I think the 4004 was first, then the 8008, then the 8080, then the Z-80? The Altair 8800 with an 8080 processor was all the rage in the mid-70's. I recall Altair also offering a machine with a Motorola chip (6800?) that predated the 6502 of Apple ][ and Commodore 64 fame. I bought the Model I TRS-80 in February, 1978. Brings back some old memories programming in assembly code back in the day. Google "Bruce Hansen TRS-80 TASMON". That was a machine language monitor program I wrote in around 1981. It was for debugging assembly/machine code programs. REAL geek stuff. I was such a nerd. . . .
Bruce