steveg@SAIC.COM (Stephen Harold Goldstein) (12/07/89)
For those interested, I picked up a Seagate 277N (65Meg) drive at the D.C. AtariFest, and got similar performace figures to those posted for the 296N - ~55KB/sec for 1:1, and ~330KB/sec for 1:2. I was in desperate need of the extra space, so I wasn't too disappointed with having to go 1:2, and I really haven't noticed that much of a difference - should only show up on massive file moves. Then again, seeing 500+KB/sec on my other drive (the 30Meg mech. from my Supra 30) is enough to make me curious about tweaking 1:1 out of the 277N. I'm using a Supra host adaptor (from the old drive), Supra software, and Toad Computers' 1/2 height under the Mega style HD case -- a little pricey ($119), but I needed its form factor.
dsmall@well.UUCP (David Small) (12/12/89)
The basenote discusses the 277N drives and interleaves. Steve, I have both the 277R and 277N; the 277R runs with an OMTI 3527 controller, that I recommend without reservation, at 1:1. As you may know, the Spectre v.1.51 had a problem with the 277N. File copies to the 277N, when the drive was formatted at 1:1, would sometimes fail. We *finally* tracked it down to the Seagate onboard controller board. The board was not capable of accepting SCSI commands immediately after transferring data; a delay was needed. This is the first drive we'd seen that required this delay, out of many. (And heck, maybe *we* are the ones out of SCSI spec). My 277N worked fine under TOS at 1:1 interleave, so my guess is that Atari is using different I/O code with a delay, or the natural overhead of GEMDOS is adding sufficient delay. It doesn't take much to make the 277N start working with 1:1 -- just turning on Spectre's disk monitor will do it. I've been told repeatedly that Seagate has done many different revisions of the controller ROM, some to try to fix this problem, by manufacturers who buy the Seagate products in quantity. (It drives them up the wall, too.) Hence, my 277N experience may not apply to you, so you know. Nowadays, we recommend "Slow SCSI" or 1:2 format on Seagate 277N, 296N, and 157N drives. I think possibly the 4096 80 mb unit wanted it, but can't recall. Hope this helps some. -- thanks, Dave / Gadgets (!hplabs!boulder.edu!tcr!gadgets!dsmall)