mrh@Shasta.STANFORD.EDU (Marc Hannah) (06/09/87)
I was quite glad to see that the Mac II rated highly in the infoworld
review which was just released. I was unhappy to see that there were two
inaccuracies which I hope someone from Apple will write and comment on.
The worst of the two was the claim that the 256K ROM in the Mac II
is the same as that in the Mac SE. This has been a terrible source of confusion
and I hate to see it go uncorrected.
The second silly thing is the comment that the 68020 'emulates' the
68000 so the Mac II is software compatible with the earlier Macs. This may
just be a technical point but the 68020 doesn't EMULATE the 68000 but rather
is a superset of the 68000. This is a subtle but important point since e
the 80386 can only run 8088 programs in the 'emulation' mode which is evidently
much less efficient than the standard mode. I hate to see people in the IBM
world apply their problems to the Macintosh (someone asked me recently if
the Mac had a limit of 640K of memory). While not as serious as the above
ROM error, it seems like it should be mentioned.
Again I hope Apple responds to this article since they are incorrect
FACTS about the Mac, not opinions.
Before I go I just want to join the chorus of those thanking the Apple
people for their contributions here. Thanks!
David Gelphman daveg%slacvm.bitnet@forsythe.stanford.edudarryl@ism780c.UUCP (06/09/87)
In article <1746@Shasta.STANFORD.EDU> mrh@Shasta.STANFORD.EDU (Marc Hannah) writes: > I was quite glad to see that the Mac II rated highly in the infoworld >review which was just released. I was unhappy to see that there were two >inaccuracies which I hope someone from Apple will write and comment on. . . . . > The second silly thing is the comment that the 68020 'emulates' the >68000 so the Mac II is software compatible with the earlier Macs. This may >just be a technical point but the 68020 doesn't EMULATE the 68000 but rather >is a superset of the 68000. This is a subtle but important point since e >the 80386 can only run 8088 programs in the 'emulation' mode which is evidently >much less efficient than the standard mode. I hate to see people in the IBM >world apply their problems to the Macintosh (someone asked me recently if >the Mac had a limit of 640K of memory). While not as serious as the above >ROM error, it seems like it should be mentioned. The first silly thing here is that the 80386 'emulates' the 8086 (or 88, they support the same programmer interface). This may be just a technical point but the 80386 doesn't EMULATE the 8086 but rather is a superset of the 8086. This is a subtle but important point since emulation modes, like that on the VAX for PDP-11's, tend have implementation problems, and support _almost_ all of the machine they emulate. The 386 however runs 8086, 80286 and 80386 programs without any notable loss of efficiency. I hate to see people in the Mac world mistate the case of the Mac's competitors. While not as serious as the above errors, it seemed like it should be mentioned. :-) (You can perhaps guess the second silly thing here.) >Before I go I just want to join the chorus of those thanking the Apple >people for their contributions here. Thanks! Double ditto for me! --Darryl Richman, INTERACTIVE Systems Corp. ...!cca!ima\ >-!ism780c!darryl ...!sdcrdcf/ The views expressed above are my opinions only.
han@apple.UUCP (06/11/87)
In article <6564@ism780c.UUCP>, darryl@ism780c.UUCP (Darryl Richman) writes: > ... The 386 however runs 8086, 80286 and 80386 programs without > any notable loss of efficiency. ... > My understanding was that the 386 emulating the 283 resulting in about a 50% loss of MIP rating. ===================================================================== Byron Han | UUCP: {sun,voder,nsc,mtxinu,dual}!apple!han Apple Computer, Inc. | CSNET: han@apple.csnet 20525 Mariani Ave, | ATTNet: 408-973-6450 Cupertino, CA 95014 | GENIE: BYRONHAN APPLELINK: HAN1 MS 27Y | CSERVE: 72167,1664 ===================================================================== All opinions and statements do not necessarily represent those of my employer, Apple Computer Inc. =====================================================================