Date: Fri, 11 Apr 97 14:30:39 METDST From: Rob Schofield <rschof@mccomm.nl> To: freebsd-hardware@freebsd.org (Hardware list at FreeBSD) Subject: Synch SCSI data Message-ID: <199704111230.OAA21211@mccomm.nl>
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Hi there. Although this question on the face of it appears to be primarily SCSI, I have posted it here as I think it's a hardware related matter. I have a DEC 433MP, and the primary bus is EISA (32 bit). The SCSI card for the disks is my old AHA-1742A, configured without floppy controller active. I have a number of SCSI disks on the bus of mixed vintage, and the bus is terminated actively on the last device in the chain, and on the host adaptor itself. The host is set to negotiate for Synchronous data exchange with any drives that support it; my main system disk is at address 0 (don't you just LURVE DOS systems...;), a Fujitsu M2694ESA, 1G FAST SCSI-2. This (I am reasonably sure) is also set to negotiate for Synch (yes, I know, only one should). I am not actually sure whether or not the disk and host ad are negotiating to run Synch SCSI data exchanges, and non of the system utils I have under any of the OS's I'm using on this machine allow me to see whether the handshake is synchronous after boot; I'm running 2.1.6 and wondered if there was any way of checking this out? Secondly, since I am multi-booting from a DOS partition to BSD, the boot loader is not run directly at boot time, but afterwards. The dmesg listing shows the loader is finding the host and all the other drives correctly, but not indicating if any of them have gone synchronous. Is this intermediate load procedure stopping it going synchronous at load time? The disk is a few years old now, so I'm not likely to make awarranty claim, but I've only recently become suspicious about this due to the observed data transfer rates (~750K/s) which seems to me to be rather low. Anyone have any ideas/Rude comments? Rob Schofield -- Witticisms are hard to define on Monday mornings... schofiel@xs4all.nl http://www.xs4all.nl/~schofiel rschof@mccomm.nl
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