[comp.sys.mac] ROMs on SIMMs

frel@randvax.UUCP (Dave Frelinger) (09/30/88)

    While reading through the Macintosh Family Hardware Reference Manual I
noticed the reference to using a 64 pin SIMM on the MacII logic board to
hold the ROMs. (Those with the manual see pages 16-14 and 18-9 to 18-12) A
couple of questions come to my mind: (1) Is the ROM SIMM option intended
to replace the ROMs on the logic board or just supplement them is some
way? (2) Is this an option Apple is really offering to users, or is it
just something theyu are technically capable of and included in the manual
to taunt those of us who fear the growing number of patches in the system
file? :-)

   If Apple does, or intends to offer the SIMM ROM option it makes the
already dubious options of an expensive logic board swap to get many of
the MacIIx's features look even questionable by allowing the an old MacII to
duplicate most features of the MacIIx by adding a PMMU, a 68882, and
new ROMs in lieu of a logic board swap.  I would guess that it would be
cheaper to upgrade a vanilla MacII with the added chips then getting the
IIx logic board option.  If anyone knows what the status is of the SIMM ROM
option I would love to hear the story.
			Thanks,
			       Dave
------------------------------------------------------------------------
Dave Frelinger
The RAND Corporation
frel@rand-unix.ARPA

Traditional Disclaimer: The opinions expressed are mine, and do not
represent those of The RAND Corporation or its sponsors.

bob@eecs.nwu.edu (Bob Hablutzel) (10/03/88)

>    If Apple does, or intends to offer the SIMM ROM option it makes the
> already dubious options of an expensive logic board swap to get many of
> the MacIIx's features look even questionable by allowing the an old MacII to
> duplicate most features of the MacIIx by adding a PMMU, a 68882, and
> new ROMs in lieu of a logic board swap.  I would guess that it would be
> cheaper to upgrade a vanilla MacII with the added chips then getting the
> IIx logic board option.  If anyone knows what the status is of the SIMM ROM
> option I would love to hear the story.

  Apple does indeed offer the SIMM ROM option. It's called a "Macintosh IIx".
One of the features of the new IIx is the SIMM ROMs. Frankly, to me it
seems like one of the best features (and something that should have come
long ago...)

Bob Hablutzel		BOB@NUACC.ACNS.NWU.EDU

wetter@tybalt.caltech.edu (Pierce T. Wetter) (10/07/88)

>  Apple does indeed offer the SIMM ROM option. It's called a "Macintosh IIx".
>One of the features of the new IIx is the SIMM ROMs. Frankly, to me it
>seems like one of the best features (and something that should have come
>long ago...)

  My personal paranoia suggests that the reason for the SIMM ROM's are that
the IIx's roms are written in '020 code. Look for a new release optimized for
the '030 and its data cache.

Pierce

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chari@juniper.uucp (Christopher Michael Whatley) (10/08/88)

In article <8224@cit-vax.Caltech.Edu> wetter@tybalt.caltech.edu.UUCP (Pierce T. Wetter) writes:
>>  Apple does indeed offer the SIMM ROM option. It's called a "Macintosh IIx".
>>One of the features of the new IIx is the SIMM ROMs. Frankly, to me it
>>seems like one of the best features (and something that should have come
>>long ago...)
>
>  My personal paranoia suggests that the reason for the SIMM ROM's are that
>the IIx's roms are written in '020 code. Look for a new release optimized for
>the '030 and its data cache.

It may be partially for that reason but, I hear from the various rumor columns
that the new ROMs will be totally object-oriented. Sounds nice doesn't it?
Sounds kind of like a NeXt doesn't it?i

Chris
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jimc@iscuva.ISCS.COM (Jim Cathey) (10/11/88)

In article <5268@juniper.uucp> chari@juniper.UUCP (Christopher Michael Whatley) writes:
>>My personal paranoia suggests that the reason for the SIMM ROM's are that
>>the IIx's roms are written in '020 code. Look for a new release optimized
>>for the '030 and its data cache.
>
>It may be partially for that reason but I hear from the various rumor columns
>that the new ROMs will be totally object-oriented. Sounds nice doesn't it?
>Sounds kind of like a NeXt doesn't it?

Oooohhhh!  Now I can't wait for those new object-oriented keyswitches and 
object-oriented line cords to become available too!

Incidentally, socketed ROMs existed in this world long before they were placed
on a SIMM carrier.  My Mac 128K has them.  So why all the fuss?  Aren't they
socketed in the Mac II?

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stevel@eleazar.dartmouth.edu (Steve Ligett) (10/14/88)

In a discussion of the IIX roms on SIMMs,
In article <2066@iscuva.ISCS.COM> jimc@iscuva.ISCS.COM (Jim Cathey) writes:
>Incidentally, socketed ROMs existed in this world long before they were placed
>on a SIMM carrier.  My Mac 128K has them.  So why all the fuss?  Aren't they
>socketed in the Mac II?

Using the SIMM (just a little PC board, for those who never knew), makes it
easier to replace the ROMs.  No tools are required, and there are no pins
to bend or break off.
   Steve Ligett     steve.ligett@dartmouth.edu or
(decvax harvard ihnp4 linus)!dartvax!steve.ligett

korn@eris.berkeley.edu (Peter "Arrgh" Korn) (10/15/88)

In <10426@dartvax.Dartmouth.EDU>, stevel@eleazar.dartmouth.edu (Steve Ligett) said:  
>In a discussion of the IIX roms on SIMMs,
>In article <2066@iscuva.ISCS.COM> jimc@iscuva.ISCS.COM (Jim Cathey) writes:
>>Incidentally, socketed ROMs existed in this world long before they were placed
>>on a SIMM carrier.  My Mac 128K has them.  So why all the fuss?  Aren't they
>>socketed in the Mac II?
>
>Using the SIMM (just a little PC board, for those who never knew), makes it
>easier to replace the ROMs.  No tools are required, and there are no pins
>to bend or break off.

Something nobody seems to have brought up as to a possible reason why
Apple puts the ROMs on SIMMs:  I know of no EPROM burner that accepts SIMMs...


Peter "what, me cynical?" Korn
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Peter "Arrgh" Korn
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