Monday, April 17, 2017

Classic Mac Emulation in the Browser

Internet Archive (via Jason Scott, Hacker News):

After offering in-browser emulation of console games, arcade machines, and a range of other home computers, the Internet Archive can now emulate the early models of the Apple Macintosh, the black-and-white, mouse driven computer that radically shifted the future of home computing in 1984.


The first set of emulated Macintosh software is located in this collection. This is a curated presentation of applications, games, and operating systems from 1984-1989.

James Friend:

This is great because it provides the same level of accessibility and convenience to emulation as you’d expect of playing a media file or viewing a document.

When you start up the emulated computer on these pages of the Internet Archive, you’re running the PCE emulator, originally a piece of software intended to run natively on desktop operating systems, which has been adapted and recompiled to run in your web browser. As the person who did the initial work of porting this emulator, I thought it would be worthwhile to provide a run-down of the tools and gross hacks which made this possible.


I realised that in classic Mac OS, the mouse position is stored in a few fixed absolute locations in the computer’s memory, called ‘low memory globals’. Basically, I directly write the mouse position value into the emulated computer’s memory.


It’s pretty strange to see adding more and more stuff that’s under copyright without explicit permission.

Update (2017-04-19): See also: John Gruber.

3 Comments RSS · Twitter

Funny how the performance of System 7 emulated in a browser on a ~2013 MacBook Pro in Safari feels about on par with what you got out of a real Mac Classic.

@Lukas The booting is definitely much faster in the browser. Floppies were really slow. My guess is that actually using the apps is also faster in the browser, but it’s hard to be sure.

Yep, booting the OS in the emulator is much faster, but actually starting and running the apps seems comparable. Our Classic had a hard disk, so that might skew the results a bit, though. Booting still took minutes, IIRC.

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