A large part of this stems from having a shoe-string budget.
The small size of the development team limited complexity. The power consumption had to be kept below 1W so that a plastic package could be used; a ceramic package would have cost more than the chip itself.
I can't place the link, but everyone who touched the PC @ IBM was doomed by it.
For a while, PCI roamed the Earth. It's still around in forms.
I'm not so sure that the original ISA bus wasn't the master stroke - it provided for all those third-party peripherals. The various forms of PC provided for doing systems integration at a then-lower cost. This was a significant business model from say, 1985 until 1995 or so. Perhaps even past that.
To an extent, the Lisa was the computer everyone wished the PC was. It sank under its price tag.
Strangely enough, there are still PC104 bus computers around.
I think you are perhaps underestimating the cost component of the barrier to entry for SGI and other "better" computers. They were often the price of a newish used car.
-- Les Cargill
I think David meant ISA as in "Instruction Set Architecture", not the ISA bus.
I agree with him, BTW. :-)
Simon.
-- Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP Microsoft: Bringing you 1980s technology to a 21st century world
What processors at that time were cranking over 1 watt? I recall lots of CPUs at that time with reasonable power levels. The original ARM was no competition for a desktop type CPU like the x86.
The real test of a CPU is the power for a given amount of work. There should be a power oriented Dhrystone type test. Measure the energy used while running the test and divide by the number of iterations in the test. Joules per Dhrystone.
But most processors spend a lot of time doing nothing waiting for something else to happen. PCs are the worst. Then the only thing that matters can be measured by a Watt meter.
-- Rick
But the newer one are waiting faster :-)
-- Reinhardt
On the first BBC Archimedes, one of the standard applications was a
80286 emulator that could boot standard MS-DOS and run DOS applications. It was a little slower than a real 80286 - but it was not significantly slower than a standard PC of two or three years earlier. That was just using a rather simple software emulator - when running native code, the ARM in the Archimedes rang rings round top-model PC's of the time.One of the demonstration programs was a Mandelbrot set renderer - full screen (640 x 480 pixels) renderings took 7 seconds, while PC's took minutes to complete. Another was a 3D spaceship game - IIRC, it was written in interpreted Basic on the Archimedes, but it had a level of graphics you didn't get in hand-coded assembly on PC's. And the gui on the Archimedes had features like anti-aliased fonts and full window movement that were not seen on PC's until perhaps 8 years later.
Obviously these are best-case examples, and it is hard to do an apples-to-apples comparison of systems from 25 years ago, but I believe the early ARM chips completely outclassed the available x86 chips in pure processor speed. And the Acorn software engineers and the RiscOS operating system completely outclassed anything MS (or Apple) could come up with.
(Acorn and ARM were not alone in this respect, historically. For example, the Commodore Amiga with its 68k processor was far faster, and had much better software, than PC's of the time.)
I don't know much about the Acorn, but the 68k on Amiga was assisted by blitters and such which did a lot of the heavy lifting and gave the impression of relativity fast system, whereas on PC of that era the 8086 had to do most of the work all by itself. A 8 MHz 68K wasn't that fast, though it did have a much, much nicer instruction set than the 8086 and
80286.
Ah; my bad.
-- Les Cargill
The game was Zarch by David Braben (of Elite fame), but the story about it being written in Basic is false. IIRC it had a loader written in Basic, which some journalists mistook for the game itself.
-a
Might remember wrong, but I think the SPARC is following the Berkley RISC approach.
BR Ulf Samuelsson
The ARM (Acorn RISC Machine) was initially design for the BBC Microcomputer TV Series. Once available they tried to sell it to the embedded world, with focus on laserprinters. This was a total failure.
The critical moment was the design-in at Apple for the Newton PDA.
The Newton was a total failure, but at its introduction, this was not known, and Semiconductor Companies had learned the need for binary compatability from the PC market, so many companies licensed the ARM core for use in ASICs, which they hoped then to sell to Apple.
With the ARM core available, people started to design ASICs with the core.
When I worked at National Semiconductor, Ericsson Mobile Phones started a study (IIRC around 1995) to replace the Z-80 they were using in the GSM phones, and the main contenders were the ARM-7, AVR and the CR-16.
There were some criteria:
It was good timing, because while the CR16 was real low power, it only had 128 kB address space, beeing a 16 bit machine. it was to be redesigned with a larger address space.
While working in the National Research Labs, I ran a project to make a synthesizable core, and together with my Manager, we made sure that National focused on IAR compilers for all parts.
ENEA could get an RTOS very quickly once needed. My only problem was that they designed the core with 2 MB address space, When the "official" project started, they requested working samples within 2 months. I still remember the expression on the VP of Microcontroller, when he found out from the manager of the Architecture group that they had been aware of the 4 MB address space requirement for 2 years...
The ARM architecture was judged as almost, but not completely useless for mobile phones, and Ericsson selected the AVR.
ARM redesigned their core to include the Thumb instruction set. At the same time, at National Semiconductor's request, (based on my studies :-) they also designed a synthesizable ARM core. I do not think National ever used the core though.
Most other mobile phone vendors were using ARM-7. Ericsson ran out of steam with the AVR around 2001 or so, and then went for the ARM-9 and later as many others the Cortex-A series.
The first general purpose ARM microcontroller was the Atmel AT91M40400, which I think was introduced around 1998.
BR Ulf Samuelsson
BR Ulf Samuelsson
So which of these features did the PowerPC or MIPS not have? I guess PowerPC was not availble as HDL, but wasn't MIPS being used in ASICs already?
Any idea why the ARM was thought useless? Was it too large and power hungry compared to the tiny AVR?
I guess your window into the scene is limited to what could be seen from inside National Semi?
-- Rick
and
took
essential
to
mismanagement
I work with a lot of safety-critical embedded customers, and most of the ones I have seen prefer PowerPC.
All that being said, never underestimate the value of a good tooling infrastructure to the success of a chip. There are a lot tools out there for ARM chips making it easy to experiment with.
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