MAME 0.273 was released at the end of 2024 and it features working support for the Mac PowerBooks 140, 145, 145B, 160, 165, 165c, 170, 180, and 180c.

The portable train has kept on rolling since then, too:

Yes, it’s the entire 68030 lineup of the PowerBook Duo, plus two 68040-based models.

And finally, but definitely coming after those PowerBook Duos, we’ve had a breakthrough in the emulation of the NuBus Power Macintoshes!

MAME 0.268 was released overnight US time by our handsome and talented coordinator Vas Crabb and it features 5 new working Macintosh models: the IIfx, Quadra 900, Quadra 950, Macintosh Portable, and PowerBook 100.

I’ve mentioned the first 3 quite a few times in recent posts, but the last two I saved as a little surprise since the final progress on them came late in the cycle.

The Macintosh Portable weighed 16 pounds (7.3 kilograms), making it not exactly portable in the sense we understand now, and contained a 15 MHz 68000 and up to 9 MiB of static RAM plus a non-backlit monochrome 640×400 LCD display and a lead-acid battery. Naturally that didn’t sell well, even after a small revision to add a backlight (which just made the battery life even worse).

Apple’s design team then worked with Sony to repackage the same internals (minus the floppy drive) into the PowerBook 100, which was the first instance of the modern laptop form factor, with the pointing device (a trackball in this case) centered nearest the user and the keyboard pushed back towards the screen. PC laptops at this time had the keyboard all the way forward, which wasn’t great ergonomics and left no good place for a trackball or track pad when Windows 3.x started to take off.

Other Mac improvements in this version include correct memory size settings for the Mac II and related machines (IIx, IIcx, and SE/30). You can no longer select memory sizes on the original Mac II that caused real hardware to malfunction due to ROM bugs (this was fixed for the Mac II FDHD). In some cases the bad RAM sizes would even cause MAME to freeze, not just the emulated machine. An issue where mouse movements could become erratic and the mouse button would sometimes click by itself on some machines (particularly the IIci and IIsi) has also been fixed. The cursor now tracks smoothly on all supported Macs.

Along with these changes I’ve updated the MAME Macintosh user guide on the wiki.

Continuing on from the previous post, ADB and the floppy drive interface have been fixed for machines with the “IOP” co-processors (Mac IIfx, Quadra 900, and Quadra 950). The floppy drive is interesting because the IOP actually does DMA transfers to and from it, making the IIfx the first Mac to be able to do that.

The IIfx’s SCSI uses a one-off custom chip used only in that machine called “SCSIDMA” which promises DMA to and from SCSI devices. Unfortunately, despite some code to do just that in the SuperMario “System 7.1” source tree that’s been around for 15+ years now, no shipping version of Mac OS that supports the IIfx (6.0.5 through 7.6.1) actually uses the DMA mode, preferring the same “handshake PIO” as most other 68K Macs instead. On the plus side that made support relatively simple to implement, and the IIfx, Quadra 900, and Quadra 950 will all be promoted to working systems in MAME 0.268 when it arrives.

I haven’t dug into the unique “SCSI DMA” on the Mac IIfx yet, but as I mentioned in the previous post, the Quadra 900 and 950 have the IIfx’s “IOP” co-processors combined with perfectly normal Quadra-series 53C96 SCSI. Turns out when you put them together, you get a running system. It’s not perfect yet (floppies don’t work, serial is questionable, and System 7.6.1 hangs if extensions are enabled) but it’s a good start.