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From: jcav@quads.uchicago.edu (john  cavallino)
Newsgroups: comp.sys.amiga.advocacy
Subject: Re: Mac and Amiga (Games--Macintosh vs A500)
Message-ID: <1991Mar16.020812.14656@midway.uchicago.edu>
Date: 16 Mar 91 02:08:12 GMT
References: <1991Mar15.092920.16477@neon.Stanford.EDU> <1991Mar15.165054.27261@convex.com> <1991Mar16.013410.13890@neon.Stanford.EDU>
Sender: jcav@midway.uchicago.edu (john  cavallino)
Organization: University of Chicago
Lines: 41

In article <1991Mar16.013410.13890@neon.Stanford.EDU> torrie@cs.stanford.edu (Evan Torrie) writes:
>swarren@convex.com (Steve Warren) writes:
>
>>In article <1991Mar15.092920.16477@neon.Stanford.EDU> torrie@cs.stanford.edu (Evan Torrie) writes:
>>>daveh@cbmvax.commodore.com (Dave Haynie) writes:
>>                                     [...]
>>>>Certainly not MOST Mac IIs.  The IIcx here in my lab only has two banks of
>>>>SIMMs.   It supports (at least I think it does...) up to 16Mbit SIMMs, which 
>>>>would give you 32MB, if fully populated.                    ^^^
>>>
>>>  Hmm... you must have been thinking of beer last night Dave. 2 banks of SIMMs
>>>= 8 SIMMs * 16MB each = 128MB.  A firm demonstrated just such a setup
>>>at January's MacWorld (of course I wouldn't like to pay for that much memory)
>>                                     [...]
>
>>Dave clearly stated 16 Mbits, not 16 Mbytes.  If you want to take issue, you
>
>  Whoops.  I missed the Mbit, although I can offer in my defense the
>fact that I've never seen anyone quote SIMM capacities in terms of
>bits.  When I go down to the local Fry's I buy 256K byte SIMMs, or 1M
>byte SIMMs, or 4M byte SIMMs. 
>  Anyway, the maths [<- note the spelling :-)] is still wrong.  If you
>have a 16Mbit SIMM, that means there's 2MB of RAM on the SIMM.  Now,
>there are EIGHT SIMM sockets on the Mac IIcx, so that would make 16MB
>of RAM total, not 32.
>  Also, the IIcx doesn't accept 2MB SIMM chips, only 256K, 1MB, 4MB
>and 16MB SIMMs, so plugging in a 16Mbit SIMM wouldn't work.
>
>  Who cares really?  What's a factor of 4 between friends? :-)  

SIMMS are sized in megaBYTES.  Most SIMMs have 8 (9 with parity) Nx1 chips on
them, making the SIMM capacity N bytes. (yes, I know Apple's newer 256K
SIMMS have two 256x4 instead of eight 256x1).  I suspect (never having seen
one) that the SIMMs in question have eight 16megabitx1 chips, giving each
a capacity of 16MB. I suspect the original poster merely made a typo.

-- 
John Cavallino                      |     EMail: jcav@midway.uchicago.edu
University of Chicago Hospitals     |    USMail: 5841 S. Maryland Ave, Box 145
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"Opinions, my boy. Just opinions"   | Telephone: 312-702-6900