Article View: comp.sys.mac
Article #6030Re: Mac IIci SIMMs
From: Noah Price
Date: Mon, 09 Oct 1989 06:29
Date: Mon, 09 Oct 1989 06:29
21 lines
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1631 bytes
Just a minor correction...
In article <35341@apple.Apple.COM> marc@Apple.COM (Mark Dawson) writes:
>(2) As I understand it, a 1 meg chip only has 10 address lines, but you need
>20 bits to address the full 1 meg. So what you do (for a read) is to put the
>low 10 bits of the address on the address lines, and strobe the CAS line. You
^^^^^^^^^^^--not really, but ok in theory RAS~--^^^
>then but the upper 10 bits of the address on the address lines, and strobe the
^^^^^^^^^^^^^--again, not really
>RAS line. Now you have given the chip the "full" address, and it will output
^^^--CAS~
>the data you want.
So, RAS~ is asserted first with the address of the row, followed by CAS~ with
the address of the column within that row. CAS~ can be asserted repeatedly to
get other columns from that row.
noah price Mac IIci Hardware Design Team
Apple Computer, Inc.
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Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!ginosko!gem.mps.ohio-state.edu!apple!noah From: noah@Apple.COM (Noah Price) Newsgroups: comp.sys.mac Subject: Re: Mac IIci SIMMs Summary: More on fast-page-mode on the Mac IIci Keywords: fast page mode Mac IIci Message-ID: <35381@apple.Apple.COM> Date: 9 Oct 89 06:29:35 GMT References: <10730@phoenix.Princeton.EDU> <35341@apple.Apple.COM> Followup-To: comp.sys.mac Organization: Apple Computer Inc, Cupertino, CA Lines: 21