Does the ECP parallel port specification require the use of a DMA channel?
No, but a specific device driver may make use of it if available. For example, if your PC and printer both support ECP mode, but your printer’s port has no DMA channel assigned, the Windows 95 printer driver will use Fast Centronics mode instead of ECP. This is faster than SPP (original) mode, but not as fast as ECP mode. Q: All the I/O cards I’ve seen require you to select a DMA channel when you jumper the parallel port in ECP mode. Yet, you can set up the “ECP Port” in Win95 with or without any DMA channel (and with or without any IRQ, for that matter). So, if I set up the parallel port on my I/O card to ECP mode with a DMA channel, but set up the “ECP Port” option in Win95 NOT to use any DMA channel, can I still use that DMA channel for another device? A: Yes.