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Mac OS 7.5.5 running on Apple Watch [video]

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Re: Mac OS 7.5.5 running on Apple Watch [video]

#14
post #5
post #3

In theory Apple Watch has the processing power for significantly > OS 7 http://www.cultofmac.com/320279/how-powerful-is-the-apple-wa...

MacOS System 7.5.x shipped on ~100MHz PowerPC chips with ~24MB of RAM, a bit higher in the later models. So the Watch most certainly has more processing power. The real problem is emulating PPC -> ARM, which is a very slow process, and why the boot time is so long in the video.

Not to mention the classic MacOS of that era had considerable amounts of code still written in 68k assembly, so a lot of what you're seeing is actually being emulated as 68k -> PPC -> ARM.

Re: Mac OS 7.5.5 running on Apple Watch [video]

#15
post #8

Earlier quoted context omitted.

For the record, my Performa 6116CD which shipped with 7.5 had a 60 MHZ PPC 601 and 8 MB RAM. It could run on significantly less than that as well - in fact I believe it ran as far back as on some 80s machines.

Yup. I had an LC520 (25 MHz 030--not that far back from your 6116) that ran 7.5.x.

7.5.5 was the last version that ran on the Mac Plus, SE, Classic, and various other 8MHz 68000 Macs.

Re: Mac OS 7.5.5 running on Apple Watch [video]

#16
post #5
post #3

In theory Apple Watch has the processing power for significantly > OS 7 http://www.cultofmac.com/320279/how-powerful-is-the-apple-wa...

MacOS System 7.5.x shipped on ~100MHz PowerPC chips with ~24MB of RAM, a bit higher in the later models. So the Watch most certainly has more processing power. The real problem is emulating PPC -> ARM, which is a very slow process, and why the boot time is so long in the video.

Processing power is not only frequency and memory. Different instruction sets might show drastically different performance. Processor cache might be higher on old computer (or might not, of course). Memory bandwidth or latency might differ too. I remember reading comparison between 1990 mainframe and current intel server. Mainframe has much higher memory bandwidth and performed much faster on tasks where processor cache was insufficient.

Re: Mac OS 7.5.5 running on Apple Watch [video]

#18
Aw. Apple Watch looks a lot like the Watch icon (shown when the system was busy) in the original MacOS.

Now if someone can figure out how to do pointing on a tiny screen, it might work. Maybe you wave you arm around in space and the accelerometers drive the cursor.

Re: Mac OS 7.5.5 running on Apple Watch [video]

#19
post #3

In theory Apple Watch has the processing power for significantly > OS 7 http://www.cultofmac.com/320279/how-powerful-is-the-apple-wa...

My understanding is that it is an A5 processor that is tuned for battery life, at the cost of performance. It all depends on the performance of the emulator, because OS 7 is not compiled for ARM.

> A5 processor that is tuned for battery life, at the cost of performance

It probably also has quite severe temperature scaling.

Re: Mac OS 7.5.5 running on Apple Watch [video]

#20

Over the weekend i saw an HN article about an x86 compiler written to compile using only MOV commands, after it was proven that x86 MOV is Turing Complete. I was sure this would be the most impressive waste of technology efforts i would see for a long time. I was wrong. It lasted 3 days.

One day I should finish my CP/M emulator for an MSP430 microcontroller with 2kB of ram (swapping out to external storage to emulate the CP/M 64kB address space). I got it up to the point of providing a login prompt --- it'd boot in about 10-15 seconds. You could type on it via a external PC/XT keyboard (bitbanged through the GPIO pins!), but I never got the screen to work, or any proper mass storage for disk. (The 8080 architecture is surprisingly elegant and orthogonal. The Z80's a bit of a mess by comparison.)

...what? Why are you looking at me like that?

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