3 Jun
2013
3 Jun
'13
1:27 p.m.
On Jun 3, 2013, at 3:04 PM, Fred Cisin <cisin at xenosoft.com> wrote:
On the 68000, they abandoned all chance of ANY
compatability, to build
"THE BEST 16 bit processor" (arguably succeeding). Not "too little",
but
almost "too late". X86 and MS-DOS dominated the market. Fortunately,
Jobs' "clean room" design team for the Lisa had no "real-world"
experience, and no clue to even consider working from old designs, and
using any old software. That was one of Jobs' major goals. After the
fiasco with the Apple /// that put Apple on the rocks, he was determined
that the new design would not be tainted by ANY knowledge of anything
previous. So, they picked a processor from spec sheets, and the 68000 was
the clear winner. They designed from scratch. When it came to software,
they also had to design from scratch, there did not exist any 68000
compatible, nor even easily portable code. They didn't even know to
CONSIDER compatability. Even the drives had to be different, with an
extra slot to make it easier to put thumbprints on the media.
The "Maserati of the mind" was a design team dream. priced accordingly,
and with no place to carry a bag of groceries.
Fortunately, (after Jobs was out), the Mac was
designed as a newer version
of a Lisa (and cutting the corners necessary to get it into the price
curve, albeit near the peak - does Apple still hold all records for
highest manufacturing mark-up?)
Erm, the Macintosh was designed before Jobs was out, no? He was ousted
either not long before or not long after its introduction (memory fails
me, but I know Sculley set the price point, to the dismay of the more
egalitarian design team). The Macintosh design team also had relatively
little interaction with the Lisa team except as competition (Atkinson
and Horn were both Lisa people who moved to the Mac, and thank heavens
they did).
The Mac was also a better performer than the Lisa, probably largely due
to Burrell Smith's heavy use of PALs to reduce design size and cost
(with the side effect of also reducing propagation delays). From an
engineering standpoint, it was a better design, and Burrell was most
certainly a Woz admirer.
Motorola got smart with the Power-PC and provided
superb emulation to
maintain full compatability. Why did the promised "Intel emulation" never
catch on?
Did Motorola supply that? I know it was all software, not in hardware.
On the Mac OS, it had the benefit of being fairly close to the metal,
something which the third-party x86 emulation never really got around
to. However, there were some good performers for other architectures;
Connectix's Virtual Game Station was actually a fairly good Playstation
(33 MHz MIPS R3000). Admittedly, the R3k has a VERY small instruction
set, and the x86 has a VERY esoteric one, much more so than the 68k.
So, . . .
you can be constrained by the past, but never have to start over.
Or, you can start over, and not have the inherited limitations.
Indeed. Sometimes, you can also take some really interesting drugs
and come up with something like EFI, which combines the very worst
parts of every boot ROM I've ever seen.
- Dave