geff@iastate.edu (Underwood Geoffrey Dale) (12/05/90)
In article <1990Dec5.005831.30208@mp.cs.niu.edu>, bennett@mp.cs.niu.edu (Scott Bennett) writes: > Here we go again. (sigh) If you don't have parity memory, you >don't have any way of knowing whether what was written to memory last >will be the same thing read back later. If you do have parity memory, you still don't have any way of _knowing_ whether what was written to memory last will be the same thing read back later. Your odds have increased, but two-bit errors will _still_ get you. Parity memory gives a false sense of security. If you really need more assurance of data integrity than regular backups can give, you need ECC memory. Besides, silicon memory is so much more reliable than core was that most people can ignore the problem. > [possible implications of bad data deleted] Yes, data errors can occur. Bloody unlikely these days, but not impossible. Of course, they can still occur even with parity memory, or even with _perfect_ memory -- disks can go bad, too. Parity memory does _not_ magically assure you of data integrity. > If I seem paranoid in all the above, please consider that I've >been working with computers for a fairly long time (see what you have >to look forward to? :-) and no, to my knowledge nobody had used non- >parity memory for a long time before I started (that was in 1967) either. And you had to program uphill both ways with a piano on your back, in the burning sun and whipping snow... :) Seriously, I can understand the desire for parity memory when you're working with stone knives and bearskins. Parity memory only became a joke very recently. > > > Scott Bennett, Comm. ASMELG, CFIAG > Systems Programming > Northern Illinois University > DeKalb, Illinois 60115 >********************************************************************** >* Internet: bennett@cs.niu.edu * >* BITNET: A01SJB1@NIU * >*--------------------------------------------------------------------* >* Visit the scenic Illinois Craters! Just 10 minutes * >* from New Chicago! * >********************************************************************** Geff Underwood geff@iastate.edu PS: Please, followup _only_ to alt.religion.computers. This really has nothing to do with NeXT.