WX

I just remember that the Motorola 68000 build into the ATARI-ST had a very small cache. It could be used for a funny trick to hinder the debugger. If you just wrote the next instruction with a move the 68000 executes the instruction that was there before. But if you used a debugger you would execute the new instruction. Obviously you had to make sure that no interrupts occurred.

C64 on steroids

In the early 80th I codeveloped with Klaus Roreger the Floppy-Speeder Professional-DOS. See
http://www.d81.de/ProfessionalDOS/Hardware/roms.shtml
I don't remember the exact timeframe. It must have been before 1985. Wow that was really funny. I remember looking "alien" for the first time and talking with Klaus Roreger about how to get around this (at that time) expensive bit shifting. So we came up with the idea of a latch that is automatically filled with current low order 4-Bit and could be used in the next access. See http://www.d81.de/ProfessionalDOS/Hardware/electronic.shtml#Function. It was really funny to read this after all those years. And some guys really put very much energy into documenting it. We had no debugger at that time to debug the C1541. No emulator for the hardware. Just do it. Developing software got so much easier today.