You mean five registers, all of them accessible through the sixth! I had a nice hand written note for register allocation for the Z-80; I used an stack-based IR

You mean five registers, all of them accessible through the sixth! I had a nice hand written note for register allocation for the Z-80; I used an stack-based IR and mapped the TOS to #A. I hope to god my parents haven't trashed my stuff, would love to see those perversions again :-)