The programmer's key (also known as the interrupt key) is a keyboard combination in classic Mac OS where simultaneously pressing the command key and power key can be used to invoke the MacsBug console or the built-in mini debugger (known as "MicroBug"). Using this key combination during bootup on an Old World ROM system will result in a Sad Mac error.[1]
History[]
Classic Macintosh models through the Power Mac G4 included small programmer's interrupt (⎉) and reset (◁) switches hidden near or on the back of the computer. These switches can be pressed with the end of a paper clip. Early models included a clip-on accessory to make it easier to access these switches.[2][3] As the clip-on buttons disappeared from later models, the keyboard combination could be added as an alternative through an extension (INIT) written by Apple engineer Paul Mercer for System 6.0.8 and earlier. System 7 through Mac OS 9 have this key combination built-in.[4]
Discontinuation[]
The hardware switches were retired on Macintosh models that did not support natively booting into classic Mac OS. Mac OS X was released with different debugging features and no longer supported this key combination.
References[]
- ↑ G Finder and Crash recovery by Kevin McMurtrie, Google Groups. 1996-07-17.
- ↑ Programmer’s Switch by Jeff Thompson. 2012-08-22.
- ↑ How did the “Programmer's Switch” work on early Macintosh Computers? by Brian H, Stack Exchange. 2021-04-15.
- ↑ Programmer's Key 1.4.2 by Paul Mercer, Macintosh Garden. 1992.
External links[]
- Technical Q&A 1264: Generating Non-maskable Interrupts Without a Programmer's Switch at Apple Developer Connection (mirrored 2003-04-23)
- Mac 512K Reset Interrupt Programmer's Switch closeup by Dog Cow at Mac GUI (2018-05-21)
- Clear Programmers Switch for Macintosh SE & SE/30 at MacEffects
- Programmer's key at Wikipedia
Articles[]
- Happy Birthday, Mac - How to Recover From the Dreaded Bomb Box Error Message by Sandro Cuccia at The Mac Observer (2014-01-25)