fryd@G.GP.CS.CMU.EDU (Michael Fryd) (10/13/87)
Is it possible to tell by human inspection if a SIMM is 120ns or 150ns? I have heard that the MAC II requires 120ns memory. I have also heard that some 256k SIMMs are 120ns and some are 150ns. How do I tell from looking at a SIMM if it is suitable for a MAC II? In particular, I have some 256k SIMMs that came out of a MAC SE when it was upgraded with 1 meg SIMMs. The chips on the 256k SIMMs have the following numbers on them: NEC Japan 8707EK06 41256-15 Does the "-15" mean that these are 150ns parts? I had heard that all MAC SEs came were supposed to come with 120ns parts? - Thanks for any advice. Michael Fryd Michael.Fryd@cs.cmu.edu
shap@sfsup.UUCP (J.S.Shapiro) (10/20/87)
In article <162@PT.CS.CMU.EDU>, fryd@G.GP.CS.CMU.EDU.UUCP writes: > Is it possible to tell by human inspection if a SIMM is 120ns or 150ns? > > I have heard that the MAC II requires 120ns memory. It does require 120ns SIMMs. > The chips on the 256k SIMMs have the following numbers > on them: > NEC Japan > 8707EK06 > 41256-15 > > Does the "-15" mean that these are 150ns parts? Sorry Michael. You have 150ns parts. In general the number you want is the 41256-xx number. This number describes both the layout of the ram (i.e. 256k x 1 vs 64k x 4) and the speed. The numbers will typically trail off with the two xx digits being one of the following: -10 100 ns parts -12 120 ns parts -15 150 ns parts I do not know what is done for faster RAMs. Jon Shapiro AT&T