Z80, 8080A, and Z180 on the H8 bus.

[norberto.collado koyado.com]

I agree with Douglas that the H8 bus is more tuned to the 8080A design. I noticed that my H8 runs more reliable with the new 8080A and the Z180 board. The Z80 timing is more aggressive to the H8 bus, which I had to put more attention during the board design.

 

I came across this situation which I could not understand. I have some HDOS bootable floppies that boots fine with the new 8080A board and the Z180 board . With the Z80 starts to boot and then it hangs. If I do an Init/Sysgen with the Z80 on the floppy that it hangs, then such floppy media boots fine under the Z80 board. I think I had thrown a lot of good floppies into the trash overtime as they worked fine and then suddenly stopped working.

 

I’m happy with the 8080A performance and the Z180 as well.

 

Norberto