Macintosh startup

The Macintosh startup sequence for Apple Macintosh (or Mac) computers includes hardware tests and diagnostics which can trigger the startup chimes and/or other instances of success or failure of the startup routines.

The startup sequence provides auditory and visual symbols of the computer's status and condition as it powers up, providing users with immediate feedback on the machine's soundness. Additionally, they allow the user to quickly identify any potential problems and take any appropriate actions to rectify faults.

Macs made from 1984 to 1998 used Old World ROM as the boot loader for all Macs produced around that time period. From 1998 up until the PowerPC to Intel transition, New World ROM was used for all Macs starting with the first iMac and later expanding to the first iBook and the Blue and White Power Mac G3. BootX is used as the boot loader for macOS on Old World/New World Macs. Most Intel-based Macs used Apple's implementation of UEFI as the boot loader, while those with a T2 security chip used a slightly different approach where it verifies the digital signature of the UEFI firmware via the security chip, which will then load the firmware upon successful verification. All Apple silicon-based Macs use a newer method separate from previous Macs where it uses a boot ROM located on the SoC to launch iBoot, in a similar manner to that of the iPhone and iPad.

In all instances, the startup chimes will be heard upon completion of the boot process (if successful), and a Happy Mac (or the Apple logo on newer versions) will be displayed on the screen to visually indicate that no hardware issues were found during the boot process. On the other hand, a failure to do so will result in a different outcome where a different sound will be heard in place of the startup chime. This would either be the Chimes of Death (for most Old World ROM Macs made from 1987 to 1998) or a series of simple beep codes (for Macs made from 1998 onwards). In addition, a Sad Mac with either one or two lines of hexadecimal codes will be displayed on some Old World ROM machines to visually indicate a hardware issue during the boot process.

All Macs made from 2016 to 2020 have the startup chimes disabled by default, however, it was later re-enabled on those Macs running macOS Big Sur or later; this can be disabled by the user within System Preferences (Big Sur up to Monterey) or System Settings (Ventura and later).

The Macintosh startup chime is played on power-up, before booting into an operating system. The sound indicates that diagnostic tests were run immediately at startup and have found no hardware or fundamental software problems. The specific sound differs depending on the ROM, which greatly varies depending on Macintosh model. For models built prior to the introduction of the Power Macintosh in 1994, the failure of initial self-diagnostic tests results in a Sad Mac icon, an error code, and (later) the distinctive Chimes of Death sounds.

The startup chime used in the first three Macintosh models is a simple square-wave "beep" generated at 600 Hz that was programmed in software by Andy Hertzfeld, utilizing the computers' onboard MOS 6522 VIA chip. All subsequent sounds after it are various chords. Software engineer Mark Lentczner used the Apple Sound Chip, his innovation of sound for the Macintosh, to play the C major fourth chord used in the Macintosh II that was programmed in software. Variations of this sound were employed until Apple sound designer Jim Reekes created the startup chime used in the Quadra 700 through the Quadra 800. Reekes said, "The startup sound was done in my home studio on a Korg Wavestation EX. It's a C major chord, played with both hands stretched out as wide as possible (with 3rd at the top, if I recall)." He created the sound as he was annoyed with the tri-tone startup chimes because they were too associated with the death chimes and the computer crashes. He recalls that Apple did not give him permission to change the sound and that he secretly snuck the sound into the computers with the help of engineers who were in charge of the ROM chips. When Apple discovered this, he refused to change it, using various claims in order to keep the sound intact. He is also the creator of the iconic (or "earconic", as he calls it) "bong" startup chime used in most Macintoshes since the Quadra 840AV. It was created with multiple synthesizers, one of them being Reekes' Wavestation using a modified version of the "Sandman" preset and another being an Oberheim Matrix-6. A slightly lower-pitched version of this chime is used in all PCI-based Power Macs until the iMac G3. On the other hand, the Macintosh LC, LC II, and Macintosh Classic II do not use the Reekes chime, instead using a software-programmed F major fifth chord that simply produces a "ding" sound. The first generation Power Macintosh computers also do not use the Reekes chime, instead using a chord strummed by jazz guitarist Stanley Jordan on an Ovation (sometimes incorrectly attributed as a Yamaha in some sources) steel-string acoustic guitar using the finger tapping technique. Furthermore, the Power Macintosh 5200–6300 computers use a unique chime (excluding the 5400 and 5500, which uses the same "bong" chime used in all PCI-based Power Macs) that was composed on the Fairlight CMI, which is also used in television commercials for the Power Macintosh and PowerBook series from 1995 until 1998. The 20th Anniversary Macintosh uses another unique chime, which was also composed on a Korg Wavestation using a modified version of a preset found on one of its sound expansion cards.

The chime used for all Mac computers from 1998 to early 2016 is the same chime that was first introduced in the iMac G3. It was produced by pitch-shifting the 840AV's startup chime, making it an F-sharp major chord. Since 2012, the Mac startup chime has been a registered trademark in the United States, and is also featured in the 2008 Pixar film WALL-E when the titular robot character is fully recharged by solar panels as well as in the 2007 Brad Paisley song "Online".