neese@adaptx1.UUCP (04/19/91)
>/* ---------- "Re: Maxtor, Wangtek & WD FASST 7000" ---------- */ >In article <1991Apr12.150258.26918@qut.edu.au> lemon@qut.edu.au writes: >>The problem is that when a tape is placed in the tape unit the hard drive >>makes chlunking sounds(well the same sounds it makes at power up, a reset?) >>and also after reading a number of blocks from the tape unit the hard drive >>does the same thing, which results in the software hanging. It also hangs >>when trying to write to the tape unit, the hard drive make the same sounds. > >>Has anyone any idea as to what may be wrong ? > >>PS : the SST software reports the correct ID's for the drive's. setup is on >>a 386 20Mhz, AMI bios. CHIPS chipset. > >This sounds something like a problem I'm having with an Adaptec 1540 >and SCSI tape drives. After a little experimentation, I found that it >worked fine on Compaqs and failed in the same way (hanging on reads) on >three out of three Chips & Technologies motherboards. > >I believe the problem in my case, and possibly yours, is a bug in the >C&T chipset's DMA circuitry that shorts a couple of address lines together >at a crucial time. C&T supposedly issued an errata sheet with work arounds, >but apparently all the motherboard OEMs ignored it. Odd, out of the 3 machines I have here in my lab, two of them are based on the C&T (386) chip set. They work wonderfully, allowing the adapter to run at virtually the DMA rate you set the adapter for. No slow downs due to a poorly implemented IOCHRDY signal. All the systems have some sort of tape drive on them. Anything from a Cipher ST150S2 to a WangDAT 1300. >It is also possible for a busmastering adapter to work around this bug, >but apparently Adaptec did not know how or did not realize that they should. >(My company makes a busmastering graphic adapter, and our hardware guys >ran into and solved this problem, so I know it can be done.) I would be very interested in hearing more about this. Could you Email me errata number? We are always looking for better ways to make our adapter work in some of the implementations we live in. >P.S. I haven't been able to confirm any of the above with Adaptec because >Adaptec won't talk to me ("You're not a distributor.") Why am I taking a >chance on another Adaptec product when their tech support is so non-existant? >Because after lurking here in comp.periphs.scsi for awhile, I get the >impression their products are perceived as the safest bets. Go figure. Just to let the net know. I have put together a memo to our management about all the issues I have been seeing here concerning support. You can expect a change to be taking place at Adaptec in this area. Thanks to all those who voiced thier opinions. Roy Neese Adaptec Senior SCSI Applications Engineer UUCP @ neese@adaptex uunet!cs.utexas.edu!utacfd!merch!adaptex!neese