Messages in this thread |  | | Date | Fri, 3 Jan 1997 23:07:11 -0600 (CST) | From | Edward Welbon <> | Subject | Re: Adaptec AHA2940 |
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On Fri, 3 Jan 1997, Leonard N. Zubkoff wrote:
... > the NCR/Symbios BIOS > follows the CAM specification which tried to optimize the usage of the > disk space by computing a C/H/S translation that's optimal for each disk. > This causes disks partitioned on a Symbios host adapter to have problems > on host adapters that used the fixed schemes, such as Adaptec and > BusLogic. However, the Symbios BIOS will adopt a translation that's > already present in the partition table, so you can generally move a disk > from Adaptec or BusLogic to Symbios. > > Adaptec uses either 64/32 or 255/63 translation, based on the size of the > disk being > 1GB and the extended translation option being selected.
This seems reasonable, but...
> Here's a table of what host adapter changes should and should not work, based > on the host adapter that originally partitioned the disk and whether it had > extended translation enabled: > > Old Host Adapter New Host Adapter Compatible > ======================== ======================== ========== ... > Symbios/NCR Adaptec no
Hmm... I must be missing some part of the picture. I have a seagate baracuda 15150W (4G) disk that I partitioned using an NCR 825 card. At one time I was having problems with the NCR-Seagate combination (later proven to be temperature related); suspecting the NCR card (wrongly), I tried an adaptec 2940 (wide but not ultra). Apparently, I let the disk cool just enough that I was able to boot and use the disk (though later when the disk was allowed to heat up it failed again). I do seem to remember that fdisk did not like the partition boundaries which seems to agree with your basic points, but I was able to boot OK. I am fairly sure that fdisk complained only when the disk was too hot.
I have never formatted this disk, the format is the original from seagate. In a system using an NCR 53c825 with a Symbios 4.0 bios (rather than the NCR 3.07 - I have two of these cards each with a different bios - the bios initialization messages are markedly different), fdisk claims this seagate is mapped as 133 heads, 62 sectors, 1017 cylinders of size 8246*512 bytes. On problem is that I am not sure what Symbios/NCR bios level I did the partition with. I am pretty certain that it was from the older level bios (marked as S1365 V3.07 57F700). Anyway the disk works with every scsi controller I have tried (including aha1542) provided it is not too warm.
Ed Welbon; welbon@bga.com;
If you pick up a starving dog and make him prosperous, he will not bite you. This is the principal difference between a dog and a man. -- Mark Twain
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