terryk@pinocchio (Terence Kelleher) (02/01/90)
In article <20428.633818635@G.GP.CS.CMU.EDU>, David.Black@G.GP writes: > >CMU looked into adding third party disks, but gave up. The basic problem is >that Encore's I/O architecture is based around a very intelligent controller >[:-)], so adding an unknown device to the system requires new microcode for >the controller [:-(]. Some of the SMD disks Encore sells are available in >the secondary market, but the installation procedure is Encore-specific. >One warning from CMU's experience with CDC disks; the error logs that come >with the disks log everything that might be a defect. In practice they're >too long to cope with, so we've resorted to a 24-hour breakin period with >the disk exerciser. After remapping the defects that surface during this >breakin, the disks seem to work just fine. > >--Dave I think you may be dealing with an older system here. The Multimax no longer requires manual input of bad block lists. It can read them off the drive itself. This is true for the SCSI disks and the SMD disks on the NCR controllers. An older controller from DTC did not properly read the encoded data. The format opperation is quite simple. The controller is capable of getting all important information from the disks and requires no user input. Encore does not recommend getting disks from other vendors and putting them on your Multimax. Of course, Encore would rather sell you the disks, but also many disks that are available do not perform well under high stress. The Multimax is capable of sustained disk traffic that causes serious problems in many disks. In some cases the result is a SCSI disk that hangs and holds the SCSI bus busy, preventing other disk traffic. This causes a system hang. -- Terence Kelleher Encore Computer Corporation terryk@encore.com