Hi All, Sounds like it is a bit of a non-starter... Let me know when you get things going, the software has gone through a number of revisions since the version I sent you. I'm now looking at an application that first strips all the data from an HPIB disk drive dumping it onto a PC. A second application on the PC then emulates an HPIB drive using groups of files stored in a simple directory system on the PC. Sounds like a pretty rare piece of kit - is it a commercial Speech Synthesizer or home-brew? I certainly have an operations manual, it may include some service bits and pieces. I'll take a look when I get home to the UK. I have a couple of these bus analysers at home, I used them in the initial investigations for the CS80 reader. You can use them to slow down the bus traffic on an HPIB system either to 2 transactions a second or single step. I tried using one to investigate the traffic between a 9000 300 machine and a disk drive but as soon as you slow the bus down the 300 series machine complains that the disk has timess out. Luckily I have an old HP 3562 spectrum analyser than interfaces to CS80 / AMIGO disks. You can single step though commands with no timeout problems using it as the disk controller. In the end though useful the 59401 is somewhat limited in what it can do. With the long command sequences that I was examining I ended up having to write down each octal (Yes, OCTAL - the I lost count of the number of times that I accidentally read the numbers as hex....) data packet as it appeared on the bus and then go back and try to decode what it all meant. The bus analyser also occasionally dropped the first byte of information being sent back by the HPIB disk drive. I'm currently investigating another option. NI make a GPIB+ card (ISA or PCI) that acts as both a GPIB controller and a GPIB analyser. In theory this can be set up to 'sniff' the GPIB bus and generate a log file of each GPIB bus event (with a 50 ns time resolution). The log can be as long as you want so no more laboriously copying down octal codes. I'll let you know how I get on. I don't need the manuals straight away. I'm hoping they contain some info about HP-UX file formats (and general HP-UX stuff - I have no experience with HP-UX systems) I haven't seen them yet but it's a few days since anyone checked my mail for me. Cheers Peter Brown _________________________________________________________________ Tired of 56k? Get a FREE BT Broadband connection http://www.msn.co.uk/specials/btbroadband