I can remember thinking in Hex. I think I got this TRS-80 in 1980. Wish I still had it.

I wrote my first machine code program on this computer for the Z-80 processor. It was to transfer files back and forth between a TRS-80 and a Model 100 so I could use the disk drives on the TRS-80 to store my Model 100 software.

Did you ever have a Model 100? I used to have a HUGE 3 ring binder with a printout of the complete ROM of that machine disassembled with scribbles everywhere. I scoured that for hundreds and hundreds of hours marking useful machine calls that I could use. I wrote the first assembler for that machine, in believe it or not, BASIC. LOL Then, used that assembler to write a machine language version.

Those were the days. Lots of fun.

Greg