Path: utzoo!utgpu!attcan!uunet!seismo!sundc!pitstop!sun!decwrl!labrea!agate!helios.ee.lbl.gov!lll-tis!ames!ll-xn!mit-eddie!mit-amt!mit-atrp!pshen
From: pshen@mit-atrp.UUCP (Paul Shen)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Questions about adding RAM
Keywords: RAM, Dynamic
Message-ID: <3100@mit-amt>
Date: 5 Oct 88 04:02:21 GMT
References: <3012@dalcs.UUCP>
Sender: usenet@mit-amt
Reply-To: pshen@atrp.media.mit.edu (Paul Shen)
Distribution: na
Organization: MIT Media Lab
Lines: 26

In article <3012@dalcs.UUCP> lane@dalcs.UUCP (John Wright/Dr. Pat Lane) writes:
>I have a few questions about adding RAM to a PC or XT type system:
>
>1. What memory speeds are appropriate for different CPU speeds?  What other
>   factors are involved?  Can memory chips with different ratings be mixed?
>

	For 10MHz system, 100ns is required.
	For 12MHz system, 80ns is required.
	As the thumb of the rule, memory speed has to satisfy
		memory speed < 1 / system colck
	If you mix the different ratings, it will work as long as all
the chips satisfy the above requirement.

>2. What about 64Kbit chips vs. 256Kbit or whatever?  Certain memory boards
>   I've seen seem to allow different types to be used but it isn't clear
>   whether they can be used at the same time on a board, what restrictions
>   there might be on this, or how the board would figure out what was going
>   on.

	There is dip switches to set for the appropriate type of ram chip.


					Paul Shen

pshen@atrp.media.mit.edu