OpenBSD - Understanding macppc Users

Every hardware platform is unique. The macppc architecture consists of the "New World" Apple Macintosh computers built around the PowerPC processor. These computers are servers, workstations, and home computers. OpenBSD/macppc can be a desktop operating system for day-to-day computing, but not exactly like other OpenBSD platforms.

"New World" is only one of five types of Macintosh. The Macintosh does not have hardware midi. The Macintosh keyboard does not beep.

"New World" is only one of five types of Macintosh.

There are actually around five architectures of Macintosh computers.

1. 68k Macintosh (mac68k)
2. NuBus PowerPC Macintosh (/dev/null)
3. "Old World" PowerPC Macintosh (macppc)
4. "New World" PowerPC Macintosh (macppc)
5. Intel-based Macintosh (i386)

The oldest 68k Macintosh and the newest Intel-based Macintosh are not PowerPC machines. The NuBus PowerPC Macintosh is a mostly forgetten class of slow and low-end machines that can only boot Classic Mac OS, MkLinux (a variant of Linux 2.0) or NuBus Linux/PPC (a variant of Linux 2.4).

The remainder of, and vast majority of, PowerPC Macintosh hardware are Old World or New World machines. The Old World represents computers before the iMac, while the New World represents the iMac and later machines. Both classes of machines contain a PCI bus and use Open Firmware to locate devices and boot the OS. Classic Mac OS, Linux, and NetBSD boot on most Old World and New World machines. Mac OS X and OpenBSD boot only New World machines. (OpenBSD 4.1 will boot some Old World machines, but is officially only for New World machines.)

Among the New World machines, the iMac desktops and iBook laptops form the low end, while the Power Macintosh desktops and PowerBook laptops form the high end.

The Macintosh does not have hardware midi.

There is no midi(4) device on Macintosh. In actual practice, this means that OpenBSD/macppc users are unable to play MIDI files. A few old web sites that feature MIDI files will be silent on OpenBSD. OpenBSD/macppc users can still handle MIDI files by using a software synthesizer and instrument set to convert MIDI files to an audio format, such as Ogg Vorbis.

One such converter is TiMidity++. There is an OpenBSD port in /usr/ports/audio/timidity but it uses an instrument set with "copyrighted patches", thus there has never been an OpenBSD package of TiMidity++. Thus, it is inconvenient for an OpenBSD/macppc user to play MIDI files, because of the required manual conversion, and because one must use ports (not packages) to install TiMidity++.

To play MIDI files directly, we would need to modify the kernel so that we can create a pseudo-midi(4) device that pipes music to TiMidity++. We could also investigate alternate converters and instrument patches.

The Macintosh keyboard does not beep.

Traditionally, each terminal either had a visual bell, or an audible bell on the keyboard. Thus, the wscons(4) layer in the OpenBSD kernel uses a design that associates the bell (or beep) with the keyboard driver.

However, neither ADB keyboards nor USB keyboards contain a beeper, thus the beep in OpenBSD/macppc is conveniently nonfunctional. Neither the console terminal nor the console X server may beep. (Mac OS does not use a keyboard beeper, but traditionally plays a beep to the audio device. Even the Mac OS "Simple Beep" sounds better than the flat note that wscons would play. Linux is apparently able to beep to the audio device.)

OpenBSD users on i386 and some other platforms have PC/AT keyboards, and those also lack a beeper. However, the kernel pckbd(4) driver can send beeps toward the speaker(4) device. OpenBSD/macppc users do not have a speaker(4) device (which plays simple tones instead of audio), so this strategy would not work.

Presently, both the akbd(4) and ukbd(4) drivers completely ignore any beeps.

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