[cctalk] Re: i8008 and interrupts

Thanks! A couple of questions - It looks like this code trashes DE, so I assume the background code just can't use those registers? So there's no way to code a truly transparent ISR? I also notice that the 8008 lacks any kind of interrupt enable F-F, nor any EI/DI type instructions. Is that right? I guess you could always implement those with external hardware, at least. And the big question - what's your code for restoring these flags when you exit the ISR? The MCS-8 manual says that all ALU instructions always update all flags, with the exception of the rotate opcodes which only change carry. It seems that means the ZS&P flags at least would have to be restored together in one instruction. Bob