It's easy to mislead yourself with what you're getting under Windows. Even under DOS, the business of synchronizing data acquisition with real-time processes is very difficult. If you can do it under complete control of your software, having disabled interrupts in your PC, you're probably OK, but don't forget that the PC has to refresh its memory and maintain the system time of day based on interrupts, so it will be necessary, essentially to reinitialize those processes from time to time.

EPP is capable of transferring data at about a 2 MBps rate on the ISA bus. Naturally, this can't be sustained, since the PC has to do something with its data and that will take time as well. However, you might be able to compensate for latency by accompanying each byte from your 805x-type with a time stamp. How you generate that time stamp will be dependent on your imagination and will impact its utility. If you have a way of, in real time, sending your real-time to the data buffer and subsequently (meaning immediately) obtaining the value you want from the source, and putting it in the buffer along with the data, that may help manage the latency inherent in using a PC for acquiring and processing data.

RE