68k Macs, was Re: Alpha CPUs, was Re: [rescue] i860 Success
nate at portents.com
Tue May 4 09:33:36 CDT 2004
Here's a good site to cross-check your recollections of the 68k Mac:
On Mon, 3 May 2004, Patrick Giagnocavo +1.717.201.3366 wrote:
> The original Mac shipped with a 68000. Later Macs shipped with
It's not quite that simple... the Mac II (1987) and LC (1990) shipped with
the 68020. The last 68000 Macs were the Classic (1990) and PowerBook 100
> A smart programmer wrote a tool which Apple bought and distributed for
> free to everyone. It was called Mode32.
Apple had already developed a software-only solution to the 24-bit 'dirty
ROM' problem in the UNIX OS, AU/X. AU/X also served as a testbed for
32-bit Application development (it's Finder was the basis of the System 7
Finder). It's unclear why Apple didn't port their 32-bit clean software
solution from AU/X to System 7 (supposedly there were developers inside
Apple who said it 'couldn't be done').
Initially Mode32 was a commercial product, before Apple licensed it due to
the outcry from users (all early Macs had ROMs on SIMMs but Apple never
released any newer 32-bit clean ROMs except privately to developers).
Connectix had another commercial product called Optima which
brought 32-bit clean to System 6, and Maxima which allows access to 14MB
of RAM in System 6 using 'enhanced 24-bit addressing'.
On Tue, 4 May 2004, Andrew Weiss wrote:
> The Mac II was the only 68020 Mac AFAIK.
You're forgetting the original Mac LC (1990).
On Tue, 4 May 2004, Geoffrey S. Mendelson wrote:
> Todd Carson wrote:
> > I believe it was the SE/30 which was the first to have an '030, and
> > the Mac II which first had an '020.
The II came out in 1987, the IIx in 1988, and the SE/30 in 1989.
> The Mac II had a 68020, a 6881 floating point processor, and a socket for a
> The Mac IIx had a 68030 and a 6881. It also had a 1.4 meg floppy drive.
> The SE was a 68000 no MMU (no support on the chip).
> The SE/30 was a MacIIx squeezed into a Mac/SE case. 68030, 68881, and
> one modified NuBus slot (it had the connector on the end instead of the
> bottom of the card).
The SE/30 (1989) is closer to the Mac IIcx (1989) than the IIx (1988).
And the SE/30 did not have a NuBus slot or the logic for NuBus, it only
had a Processor Direct Slot (PDS). The IIsi was the direct decendant of
the SE/30 (you can take the ROM SIMM from the early IIsi and replace the
SE/30 ROM SIMM to make a 32-bit clean SE/30), and the IIsi could take
NuBus cards if you bought the PDS to NuBus 'adapter' that actually
included the NuBus logic on several chips, along with a 68882 (the IIsi
lacked a 68882, unlike the SE/30).
More information about the rescue