marr@cup.portal.com (scott andrew marr) (07/26/90)
I am have a project where it is necessary to read, as fast as possible, large amounts of data from 8mm tape, using a DECstation 3100. The data is stored on the tape by a real time data aquistion processor in 1K blocks. I have been able to open the device and read from it using the standard UNIX system calls (open & read). The problem is that I can only read 1 block per call, and the cycle time between two reads is around a second. The data on the tape is hundreds of megabytes long, so the operation is unreasonable. Does anyone know of a way to get more than just one block per read? The only thing I've come across is using something called a nbuf facility (via ioctl) that implements multiple buffers, but I'm not sure what that will do for me (or to me!). Any suggestions would be appreciated. ____________________________________________________________________________ | marr@cup.portal.com Scott Marr | or | marr@decster1.msd.lmsc.lockheed.com ____________________________________________________________________________