allisonp(a)world.std.com (Allison J Parent) Wrote: Right... but default secondary device for a DU handler is 17772144. (The reason for this is because back when the driver was developed, someone decided that since the vector was programmable, and the default was at 154, and nothing was at 150, that subsequent vectors would decrease by 4. This was then extended to the CSR... It wasn't until later that we found that the default secondary CSR was to be at 17760334. It never got changed. I think it is still that way for the to-be-released V5.7) So long as the address/vector match what is set in the device handler, it should boot. (I have a system at home with three, and at times four, MSCP adapters for various disk types -- MSCP, SCSI, ESDI, DSSI) Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com | | Unix Support Engineering Group | (home): mbg!world.std.com | | Compaq Computer Corporation | addresses need '@' in place of '!' | | 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ | | Nashua, NH 03062 | "pdp-11 programmer - some assembler | | (603) 884 1055 | required." - mbg | +--------------------------------+-------------------------------------+