> Many devices, even simple DACs and ADCs have time-out circuits in there
>> and when SPICLK hasn't come for a certain period of time during a
>> transmission they will abort for the affected data set.
>
> Actually I'm trying to do it any synch communications. SPI, I2C, and
> ICSP will be some of the protocols I'll try and implement. Kinda sucks
> that there is at time out and since SPI doesn't have an acknowledgement
> it makes it even works ;/
I believe the OP (that's you, Jon. ;-) ) has some confusion about what "synchronous comm" means. Or either I have.
The way I understood it, "sync" means that the receiver provides its own clock, and it gets sync'ed to the master by some scheme.
What you're talking about, driving something from the parallel port, is simply clocked. If you have control over the data and clock, and know how the destination device behaves when it receives them, then just do it; if your receivers are static, they shouldn't care about latency, as long as the signals get there in the right order.
Good Luck! Rich