Path: utzoo!utgpu!watserv1!watmath!att!att!linac!pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!usc!apple!snorkelwacker.mit.edu!ai-lab!rice-chex!caroma From: caroma@rice-chex.ai.mit.edu (Carl R. Manning) Newsgroups: comp.sys.next Subject: Re: memory (was: slab vs. cube and $$) Summary: Not parity memory, but ECC memory Message-ID: <12081@life.ai.mit.edu> Date: 29 Nov 90 01:42:25 GMT References: <1990Nov28.043420.19772@ariel.unm.edu> <1990Nov28.191405.25218@mp.cs.niu.edu> Sender: news@ai.mit.edu Lines: 26 In article <1990Nov28.191405.25218@mp.cs.niu.edu> bennett@mp.cs.niu.edu (Scott Bennett) writes: > Whether they have 8MB, 12MB, or even more, they'll be throwing those >SIMMs away and replacing them as soon as they can afford to when they >discover NeXT has stuck them with nMBx8 SIMMs rather than nMBx9's. Jeesh. >Nonparity memory was obsoleted in the 1950's. Here's a question: What does the NeXT do if it gets a parity error? If my machine gets hit by a cosmic ray or a chip goes bad, I don't want my machine to crash, or worse yet, become unusable (who knows what deadlines I might be under); it should correct the error and warn me about it the background so I can have it fixed in the future. As the amount of memory soars, the chances of a bit getting flipped or a chip going bad somewhere are also on the increase. Memory is cheap; add a few more bits and you can have ECC error correction of single bit errors. Perhaps futures NeXTs can be designed for people or servers who need this much reliability, at least as an option. I would think that this security could be a good selling point -- look at how 4wd cars and anti-lock brakes are selling these days. caroma@ai.mit.edu