I picked up a Softmark USB-GPIB interface at a swapmeet. Problem is that there's no way to program it. The CD installs an application that can give VERY LIMITED demo access. There's a usb.ocx control that doesn't appear to have many of the things you'd need for gpib, like setting the talk and listen addresses, asserting ATN, etc. Softmark has been very responsive, just not helpful.
Can anybody share some source code that can address an instrument and send/receive data using the softmark device? VB6 is my tool of choice, but anything would help. I guess I don't care if it uses the usb.ocx if I can bit-bang it. High performance is not an issue.
There's also some funny business going on on the bus (DAV) that I can't explain from the diagram and possible states of all the signals on the node. Using the demo app, I get replicated characters and missing characters in received data strings. Sending strings seems to work.
So far, I've got a paperweight.
Thanks, mike