On 01/15/2014 06:42 PM, Cory Smelosky wrote: A lot of people (myself included) insisted on direct-in-the-bus printer controllers when we saw how badly serial printers tanked the system when we connected them to DZ11s. ;) Oh I can imagine that. A dedicated controller would have MUCH higher bandwidth than the <1.5mbitcapable on the DZ11. ;) It's the interrupt load that's the problem. It could TANK an 11/750. Didn't the DZ11 depend on the CPU for interrupts? Every interrupt depends on the CPU. ;) Isn't that why say...the DHV11 had processors to offload serial processing to? The DHV11 has a pair of 8051s on it. The DH11 is several boards full of logic. It has buffering and DMA capability to offload the host system...it needs much less hand-holding than the DZ11. -Dave -- Dave McGuire, AK4HZ New Kensington, PA