Guru Meditation

Guru Meditation is the name of the error that occurred on early versions of the Commodore Amiga computer when they crashed. It is analogous to the "Blue Screen Of Death", often referred to as a 'BSOD', in Microsoft Windows operating systems.

Description

When a Guru Meditation is displayed, the options are to reboot by pressing the left mouse button, or to invoke ROMWack by pressing the right mouse button. (ROMWack is a minimalist debugger built into the operating system which is accessible by connecting a 9600 bit/s terminal to the serial port).

The alert itself appears as a black rectangular box located in the upper portion of the screen. Its border and text is red for a normal Guru Meditation, or green/yellow for a Recoverable Alert, another kind of Guru Meditation. The screen goes black, and the power and disk-activity LEDs may blink immediately before the alert appears. In AmigaOS 1.x, programmed in ROMs known as Kickstart 1.1, 1.2 and 1.3, the errors are always red. In AmigaOS 2.x and 3.x, recoverable alerts are yellow, except for some very early versions of 2.x where they were green. Dead-end alerts are red in all OS versions.

This error is sometimes referred to colloquially as a "trip to India," or the "Unwelcome Visitor from the East", or just "alert".

The alert occurred when there was a fatal problem with the system. If the system had no means of recovery, it could display the alert, even in systems with numerous critical flaws. In extreme cases, the alert could even be displayed if the system's memory was completely exhausted.

The error is displayed as two fields, separated by a period.The format is #0000000x.yyyyyyyy in case of a CPU error, or #aabbcccc.dddddddd in case of a system software error. The first field is either the Motorola 68000 exception number that occurred (if a CPU error occurs) or an internal error identifier (such as an 'Out of Memory' code), in case of a system software error. The second can be the address of a "Task" structure, or the address of a memory block whose allocation or deallocation failed. It is never the address of the code that caused the error.If the cause of the crash is uncertain, this number is rendered as 48454C50, which stands for "HELP" in hexadecimal ASCII characters (48=H, 45=E, 4C=L, 50=P).

The text of the alert messages was completely baffling to most users. Only highly technically adept Amiga users would know, for example, that exception 3 was an address error, and meant the program was accessing a word on an unaligned boundary. Users without this specialized knowledge would have no recourse but to look for a "Guru" or to simply reboot the machine and hope for the best.

A guru Meditation error is also known to occur in Winamp, when a script in a media playlist becomes corrupted, it shows the same error box as the Commodore Amiga Guru meditation error, except the Winamp guru meditation error does not have a flashing red border, but a solid red border

ystem software error codes

The first byte specifies the particular area of the system affected. The top bit will be set if the error is a dead end alert.

Origins

The term "Guru Meditation Error" was an in-house joke from Amiga's early days. One of the company's products was the "joyboard", a game controller much like a joystick but operated by one's feet. Early in the development of the Amiga computer operating system, the company's developers became so frustrated with the system's frequent crashes that, as a relaxation technique, a game was developed where a person would sit cross-legged on the joyboard, resembling an Indian guru. The player was supposed to remain perfectly still with the goal of the game being to stay still the longest. If the player moved, a "guru meditation error" resulted.

The error was removed from subsequent versions of the Amiga ROM (Kickstart), but some users chose to patch it back in.

Trivia

The blinking border of the original guru meditation number was created by writing the border in black 6,809 times and then writing it in red 6,809 times. This was in honor of the Motorola 6809, a popular CPU that was a favourite of the system designers.

Guru Meditation errors are also adopted in Nullsoft Winamp's script engine "MAKI" (Winamp3 and Winamp5 freeform skin engine) when something goes wrong.

Deliplayer (for Windows) also display a guru meditation if somethings goes wrong.

The Varnish HTTP accelerator also adopted Guru Meditation errors, for example:"Error 503 Service Unavailable Backend did not respond. Guru Meditation: XID: 456452130"

TechCrunch sometimes displays a text guru meditation error when its website is having technical issues.

Prevue Channel ran on AmigaOS from 1988 to December 1999. In its early days, errors could be prevalent - Guru Meditation errors among them. Once the channel went to a blue grid in 1993, errors decreased, but still could occur. After TV Guide bought the channel, a new guide was brought in that ran on different equipment.

Later versions of AmigaOS

It should also be noted that although the Grim Reaper replaces many of the alerts, the error is still called a "Guru Meditation" as seen in the first screenshot.

The program which caused the particular error used as an example here was the following:

int main(void) { int *bad=0; *bad=0; return(0); }

Other

A 503 error that includes the text "Guru Meditation".

See also

External links

* [http://www.scotek.demon.co.uk/guru.html Guru Meditation code explained]
* [http://www.atariage.com/controller_page.html?SystemID=2600&ControllerID=11 Joyboard Controller]
* [http://www.guru-meditation.net Guru Meditation] (the introduction page contains an image of the effect)
* [http://search.cpan.org/~rse/CGI-GuruMeditation-0.05/GuruMeditation.pm CGI::GuruMeditation] Perl die handler to catch abnormal CGI termination and visually mimicking Amiga behavior
* [http://www.gurumeditation.dk/ Guru Meditation] (a simulation of the effect when a corrupted disk is inserted - there are minor changes to the images)