DRV11-WA question

Does anyone have any timing info for the DRV11-WA / DR11-W cards? I am working on a Microvax II to send and collect data from a serial link used in the CF-18 aircraft (The box is real, but it is sitting in the lab!). I am modifying the XADRIVER provided by DEC to customize to my needs. I am having a few problems however... The ATTN bit does not seem to latch in the CSR when I pulse the ATTN line. Further, if I pulse it withing a few microseconds of a transfer and the transfer was < 3 words long, I miss the interrupt. (The IE bit is always set) Further, if send several QIO calls via my application program, it seems that there is an awfully large gap between the transfers (250 us to 2 ms) , yet my system is basically sitting idle. I can't figure out if it's the OS holding up the IRPs or if there is a problem elsewhere... Help! Eric Everton Avionics Simulation Specialist Dept. 49 Eric.Everton(a)cae.com (450) 476-4484