Guru Meditation
Encyclopedia
Guru Meditation is an error notice displayed by early versions of the Commodore Amiga
computer when they crashed
. It is analogous to the "Blue Screen Of Death
" in Microsoft Windows
operating systems.
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 are 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 LED
s may blink immediately before the alert appears. In AmigaOS
1.x, programmed in ROM
s 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.
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 game controller much like a joystick
but operated by one's feet, similar to the modern-day Wii Balance Board
. 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 A similar game is the final unlockable balance activity in Wii Fit
.
The error was removed from subsequent versions of the Amiga ROM (Kickstart), but some users chose to patch it back in.
Since version 4.0
of the OS, many alerts are replaced by an error handler known as "The Grim Reaper". The Grim Reaper displays the task which caused an error and the nature of the error (illegal memory access
etc.), whereupon it presents the user with several options such as suspending/killing the task, displaying more information such as a register
dump or attaching a debugger
(gdb).
Although the Grim Reaper replaces many of the alerts, the error is still called a "Guru Meditation" as seen in the first screenshot.
Amiga
The Amiga is a family of personal computers that was sold by Commodore in the 1980s and 1990s. The first model was launched in 1985 as a high-end home computer and became popular for its graphical, audio and multi-tasking abilities...
computer when they crashed
Crash (computing)
A crash in computing is a condition where a computer or a program, either an application or part of the operating system, ceases to function properly, often exiting after encountering errors. Often the offending program may appear to freeze or hang until a crash reporting service documents...
. It is analogous to the "Blue Screen Of Death
Blue Screen of Death
To forse a BSOD Open regedit.exe,Then search: HKLM\SYSTEM\CurrentControlSet\services\i8042prt\ParametersThen make a new DWORD called "CrashOnCtrlScroll" And set the value to 1....
" in Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
operating systems.
Description
When a Guru Meditation is displayed, the options are to rebootBooting
In computing, booting is a process that begins when a user turns on a computer system and prepares the computer to perform its normal operations. On modern computers, this typically involves loading and starting an operating system. The boot sequence is the initial set of operations that the...
by pressing the left mouse button, or to invoke ROMWack by pressing the right mouse button. (ROMWack is a minimalist debugger
Debugger
A debugger or debugging tool is a computer program that is used to test and debug other programs . The code to be examined might alternatively be running on an instruction set simulator , a technique that allows great power in its ability to halt when specific conditions are encountered but which...
built into the operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
which is accessible by connecting a 9600 bit
Bit
A bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...
/s terminal to the serial port
Serial port
In computing, a serial port is a serial communication physical interface through which information transfers in or out one bit at a time...
.)
Recoverable Alert
Recoverable Alerts are non-critical crashes in the Amiga computer system. In most cases, you can resume work after one, and save your data, while a normal, red Guru Meditation always results in an immediate reboot....
, another kind of Guru Meditation. The screen goes black, and the power and disk-activity LED
LEd
LEd is a TeX/LaTeX editing software working under Microsoft Windows. It is a freeware product....
s may blink immediately before the alert appears. In AmigaOS
AmigaOS
AmigaOS is the default native operating system of the Amiga personal computer. It was developed first by Commodore International, and initially introduced in 1985 with the Amiga 1000...
1.x, programmed in ROM
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
s known as Kickstart
Kickstart (Amiga)
Kickstart is a commonly used term for the bootstrap firmware of the Amiga computers developed by Commodore.Most Amiga models were shipped with the Kickstart firmware stored on ROM chips...
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.
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
ASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
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.
Guru Meditation handler
There was a little known commercial error handler for the older Amiga OS called GOMF (Get Outa My Face) made by Hypertek/Silicon Springs Development corp. It was able to deal with many kinds of errors and gave the user a choice to either remove the offending process and associated screen or allow the machine to show the Guru Meditation. In many case removal of the offending process gave one the choice to save one's data and exit running programs before rebooting the system. When the damage was not extensive one was able to continue using the machine. However it did not save the user from all errors, as one may still see this error occasionally.System software error codes
The first byte specifies the area of the system affected. The top bit will be set if the error is a dead end alert.| Area of system | Value | Specific part of system |
|---|---|---|
| Libraries | 01 | Exec library |
| 02 | Graphics library | |
| 03 | Layers library | |
| 04 | Intuition Intuition (Amiga) Intuition is the windowing system and user interface engine of AmigaOS. It was developed almost entirely by RJ Mical. Intuition should not be confused with Workbench, the AmigaOS spatial file manager, which relies on Intuition for handling windows and input events.Users may remember the initial... library |
|
| 05 | Math library | |
| 06 | CList library | |
| 07 | AmigaDOS AmigaDOS AmigaDOS is the disk operating system of the AmigaOS, which includes file systems, file and directory manipulation, the command-line interface, and file redirection.... library |
|
| 08 | RAM Handler library | |
| 09 | Icons Icon (computing) A computer icon is a pictogram displayed on a computer screen and used to navigate a computer system or mobile device. The icon itself is a small picture or symbol serving as a quick, intuitive representation of a software tool, function or a data file accessible on the system. It functions as an... library |
|
| Devices Device driver In computing, a device driver or software driver is a computer program allowing higher-level computer programs to interact with a hardware device.... |
10 | Audio device |
| 11 | Console device | |
| 12 | Gameport device | |
| 13 | Keyboard device | |
| 14 | Trackdisk device | |
| 15 | Timer device | |
| Resources Resource (computer science) A resource, or system resource, is any physical or virtual component of limited availability within a computer system. Every device connected to a computer system is a resource. Every internal system component is a resource... |
20 | CIA resource |
| 21 | Disk resource | |
| 22 | Misc resource | |
| Other areas | 30 | Bootstrap Booting In computing, booting is a process that begins when a user turns on a computer system and prepares the computer to perform its normal operations. On modern computers, this typically involves loading and starting an operating system. The boot sequence is the initial set of operations that the... |
| 31 | Workbench Workbench (AmigaOS) -Overview:Commodore named their Amiga computer's first operating system Workbench 1.0 and continued with the Workbench name until version 3.1, when it was changed to AmigaOS, prompted by Apple renaming their propriety OS from "System" to "MacOS"... |
|
| 32 | Diskcopy |
Origins
The term "Guru Meditation Error" was an in-house joke from Amiga's early days. One of the company's products was the JoyboardJoyboard
The Joyboard is a balance board peripheral for the Atari 2600 video game console. It was released in 1982 and was used by standing on top of it and leaning in a certain direction.-Design:...
, a game controller much like a joystick
Joystick
A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks, also known as 'control columns', are the principal control in the cockpit of many civilian and military aircraft, either as a center stick or...
but operated by one's feet, similar to the modern-day Wii Balance Board
Wii Balance Board
The Wii Balance Board is a balance board accessory for the Nintendo Wii video game console. Along with Wii Fit, it was introduced on July 11, 2007 at the Electronic Entertainment Expo...
. Early in the development of the Amiga computer operating system, the company's developers became so frustrated with the system's frequent crashes
Crash (computing)
A crash in computing is a condition where a computer or a program, either an application or part of the operating system, ceases to function properly, often exiting after encountering errors. Often the offending program may appear to freeze or hang until a crash reporting service documents...
that, as a relaxation technique, a game was developed where a person would sit cross-legged on the joyboard, resembling an Indian guru
Guru
A guru is one who is regarded as having great knowledge, wisdom, and authority in a certain area, and who uses it to guide others . Other forms of manifestation of this principle can include parents, school teachers, non-human objects and even one's own intellectual discipline, if the...
. 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 A similar game is the final unlockable balance activity in Wii Fit
Wii Fit
is a video game developed by Nintendo for the company's home video game console, Wii, designed by Hiroshi Matsunaga. It is an exercise game consisting of activities using the Wii Balance Board peripheral...
.
The error was removed from subsequent versions of the Amiga ROM (Kickstart), but some users chose to patch it back in.
Later versions of AmigaOS
AmigaOS 4
AmigaOS 4, , is a line of Amiga operating systems which runs on PowerPC microprocessors. It is mainly based on AmigaOS 3.1 source code, and partially on version 3.9 developed by Haage & Partner...
of the OS, many alerts are replaced by an error handler known as "The Grim Reaper". The Grim Reaper displays the task which caused an error and the nature of the error (illegal memory access
Segmentation fault
A segmentation fault , bus error or access violation is generally an attempt to access memory that the CPU cannot physically address. It occurs when the hardware notifies an operating system about a memory access violation. The OS kernel then sends a signal to the process which caused the exception...
etc.), whereupon it presents the user with several options such as suspending/killing the task, displaying more information such as a register
Processor register
In computer architecture, a processor register is a small amount of storage available as part of a CPU or other digital processor. Such registers are addressed by mechanisms other than main memory and can be accessed more quickly...
dump or attaching a debugger
Debugger
A debugger or debugging tool is a computer program that is used to test and debug other programs . The code to be examined might alternatively be running on an instruction set simulator , a technique that allows great power in its ability to halt when specific conditions are encountered but which...
(gdb).
External links
- Guru Meditation code explained
- Joyboard Controller
- Guru Meditation (the introduction page contains an image of the effect)
- CGI::GuruMeditation Perl die handler to catch abnormal CGI termination and visually mimicking Amiga behavior
- Guru Meditation (a simulation of the effect when a corrupted disk is inserted – there are minor changes to the images)