bryce@COGSCI.BERKELEY.EDU (Bryce Nesbitt) (07/30/87)
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----- An Amiga glossary. Terms and definitions often used when discussing
----- the Amiga. Copyright (C)1987 Bryce Nesbitt. All rights reserved.
----- Please don't redistribute as of yet. Please write to me if you have
----- gripes at a definition, or if you feel something should be added.
------ucbvax!cogsci!bryce -or- bryce@cogsci.Berkeley.EDU
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:-)
A net smilely. When sprinkled near a statement it indicates that it
was was not meant seriously. "The bombs drop in 5 minutes" -Ronald
Reagan :-)
()
Used to signify a routine. If I talk about Wait(), I am referring to
the routine named "Wait".
$C00000 MEMORY
Memory that sits at location $C00000. Such memory is automatically
added to the memory lists by the V1.2 operating system, yet does not
take up normal auto-config space.
AGNUS
One of the "big three" custom chips inside the Amiga. Controls RAM
addressing, DMA and other timing.
AmigaDOS
Amiga Disk Operating System. Strictly speaking, the part of the Amiga
operating system that controls the file system. Unlike MS-DOS, there
is more to the Amiga operating system that just DOS.
Workbench CLI Programs
\ | /
\ | /
\ | /
\ | /
\ | /
AmigaDOS ;DOS level
/ | \
RAM: DF0: HD0: ;FILE SYSTEM level
| | | ;(managed by handler processes)
memory disk hard disk ;DEVICE level
drive drive ;(managed by device drivers)
Programs may often bypass the DOS level by sending a packet directly to
the proper handler process.
ARP
AmigaDOS Replacement Project. A holy crusade undertaken by Charlie
Heath (of Microsmiths) to implement and distribute a free set of
improved CLI commands, and programmer facilities.
ATOM
A kludge to help developers tell their programs the differences between
FAST and CHIP memory. See FIXHUNK.
AUTO-CONFIG
A system of automatically detecting and configuring memory and hardware
without the need for millions of dip switches or direct user hassle.
Basically, the software will tell the individual board's hardware what
address ranges to respond to, and will resolve conflicts. Not actually
implemented in the Amiga until operating system V1.2.
AUTODOC
A brief, sometimes cryptic, summary of each Amiga library routine is
kept in the actual original source code. These are extracted
automatically by C-A and distributed on paper (in the RKM) or on disk
to programmers.
BOOT
From "to pull oneself up by one's bootstraps". To start or restart
one's computer from scratch. With the exception of recoverable RAM
disks, this means loosing all data in memory.
BARREL SHIFTER
The part of the blitter that can shift bit images to arbitrary
boundaries nearly instantly.
BIMMER
BLITTER
A graphics engine that is part of the custom chips. It can do BLITs
(Block Image Transfers) in hardware. Sometimes called a BIMMER (Bitmap
IMmage Manipulator) because it can also do logic operations during the
transfer, line draws, hardware fills, and more.
C-A
Shorthand for Commodore-Amiga, Inc.
CHIP MEMORY
Memory accessible by the custom chips. This contains the frame buffer,
sprites, audio DMA buffers, etc. This memory runs at twice the speed
of the 68000, which normally allows the 68000 to run without delay.
With a very busy display that has lots of extra colors, copper lists,
or blitter moves, this memory can get bogged down with all the extra
work. Fortunately there is an alternative, it's called FAST MEMORY.
CHUNK
See IFF.
CLI
The AmigaDOS Command Line Interpreter. A traditional line oriented DOS
interface. Can be though of as existing "under" the Workbench Tool.
COPPER
Display co-processor. Yet another microprocessor within the Amiga,
this time specialized at for raster synchronization. It only has three
instructions, but since it can access any of the ~100 custom chip
registers it's rather powerful. Easy tricks include changing
resolution on any line, reusing sprites later in a display, modifying
the pallette on the fly, page flipping with no 68000 involvement, etc.
DEAMON
The actual working part of a program that may do it's dirty work while
hidden in the background.
DENISE
One of the "big three" custom chips in the Amiga. Contains the video
output signals, mouse input and misc. timing.
DEVICE, EXEC
Usually a task that that talks directly to some piece of hardware. The
"keyboard.device", for example, reads the keyboard then tells the rest
of the world about it. The "trackdisk.device" is an example of a
device that can have multiple units.
Programs communicate to devices with IO requests, a form of inter-task
communication.
The standard devices are: timer, trackdisk, keyboard, gameport, input,
console, audio, narrator, serial, parallel, and printer. With each
hard drive, SCSI interface, or extra serial port, you will probably get
another exec device.
DEVICE DRIVER
The actual code that a device executes.
EHB
Extra HalfBrite. A video mode that allows 64 colors per line.
Available on all A500s and A2000s, and roughly half of the A1000s.
EXEC
The executive. Master of the Amiga. Controls task switching and low
level system details.
EXECUTE
To command a program or sequence of computer instructions to commence.
Not "put to death".
FAST MEMORY
Memory that is not accessible to the custom chips, and not subject to
possible delay, either. Most quality expansion memory fits in this
category. This is the preferred location for most program code and
data.
FILE SYSTEM
A place to store files. DF0: is one, so is RAM:.
FIXHUNK
A utility. Some older programs for the Amiga where improperly written
and will not work if non-CHIP memory is added. Fixhunk can usually fix
the problem.
GARY
Stands for "Gate ARaY", cute eh? A single custom chip used in the
Amiga 500 that replaces a large number of individual chips from the
original A1000.
GENLOCK
The capability that allows synchronizing of the Amiga's video to an
external source and the overlay of the two images.
GOLDFISH
A intellectual possession of another that is not to be abused, stepped
on, fried or otherwise compromised. :-)
HAM
Hold And Modify. A obscure, but powerful, Amiga video mode that
expresses each pixel as a modification of the last. Allows for some
nice shading.
HANDLER
On the Amiga, the code that manages a file system. Handlers often live
in the L: directory when not in use.
HEAP
A place to toss all sorts of junk.
HUNK
A subdivision of an AmigaDOS object file. HUNKS come in several
flavors including those that store CODE, DATA and BSS (uninitialized
data). If all the HUNKS in a file do not line up correctly, AmigaDOS
will report error 121, "file not an object module".
HUNKPAD
A utility that can fix files that have been damaged by XMODEM transfer.
One symptom of a damaged file is error 121, "file is not an object
module". This utility also prevents future XMODEM damage.
HYBRID MEMORY
Memory that can't be addressed by the custom chips, yet is still
subject to the delays they can can cause. Sometimes called SLOW FAST
memory.
ICON
A pictorial representation of a file. Expressed as a file with the
".info" suffix. These come in the DISK, DRAWER, TOOL, PROJECT,
GARBAGE, DEVICE and KICK flavors. The last is not used, and the second
to last is used in conjunction with auto-config.
IFF
Interchange File Format. A standard for creating file format
standards. Popular formats include ILBM (InterLeaved Bit-Map) for
raster images, SVX8 (8 bit digital samples), and SMUS (Simple MUsical
Score).
ILBM, SVX8 and SMUS are all FORMs. Each form is composed of one or
more CHUNKS. Each CHUNK holds a specific class of the file's data. For
example in ILBM FORMs there are several possible CHUNKs including BHMD
which holds the actual picture data, CMAP which holds the color map,
and DEST which has to do with converting pictures with different
depths. Any writer that does not know about DEST won't write that. Any
reader that does not care about DEST won't read it. If a program wants
a CMAP, but a file does not have it, it will use default values or make
something up. The beauty of this system is that new CHUNKS can be be
added to an existing IFF file definition without affecting portability.
INPUT.DEVICE
Where all the input from the keyboard, mouse and other user input
devices flows. Also a popular place for user interface modifying
programs to hang out.
INTUITION
"The Amiga user interface". Intuition uses the low level layers and
graphics libraries to build screens, windows, menus, gadgets and other
user interaction mechanisms.
LIBRARY
All Amiga system function calls are grouped into libraries. Commonly
used libraries include exec, intuition, dos and graphics.
LOCK
An AmigaDOS structure that prevents multitasking programs from stomping
on shared files. Other Amiga subsystems use locks for other purposes.
MMU
A device for arbitrating and protecting against a task damaging the
memory of another task. Also has lots of other uses that are beyond
the scope of this discussion. The current generation Amigas do not
contain one.
MESSAGE
A mechanism of inter-task communication.
NUKE
To destroy, demolish, obliterate, wipe out, mung, hash into little
bits, waste, screw up, or make FUBAR, by means of atomic weapons, or
with a computer.
OVERLAY
An AmigaDOS feature that allows part of a program to sit on disk, to be
brought into memory only when needed.
OVERSCAN
Any of the pixels beyond 640 (high res) or 320 (lo res) wide and 200 or
400 high that are actually used in a display. The Amiga system
software will let you specify a display as wide as 704, and as high as
464 pixels, but on most monitors some of that will be clipped by the
borders of the display monitor used. It is possible to adjust a
monitor to show that space, however. The "morerows" program can be
used to add overscan pixels to the Workbench screen. For broadcast TV
use, overscan allows the picture to use the full width of the display.
PACKET, AmigaDOS
An AmigaDOS specific message. All DOS activity is actually carried out
with a packet sent to the proper DOS HANDLER process.
PAULA
Another of the "big three" custom chips. Includes the audio DAC's,
4703 custom interrupt chip, custom serial chip, and hyper-fancy custom
disk controller.
PROCESS
A task that has been taught how to talk to AmigaDOS.
PROJECT
Workbenchism for the output of a tool. A data file.
RKM
The ROM Kernal Manual, the Amiga programmer's bible. The other two
essential books are the Intuition manual and the AmigaDOS manual(s).
These books are *not* tutorial in nature.
PUBLIC
A memory attribute that must be specified if a section of memory is to
be shared between two processes. This will become critical when a MMU
is added to the Amiga.
TASK
The system's idea of a running program. Each task thinks that it has
the main processor all to itself. Each task is wrong. It will
actually be sharing it with many other tasks. Tasks that have nothing
to do will Wait(). Waiting tasks take virtually no processor time.
TOOL
Workbenchism for "program"
UUDECODE
UUENCODE
Encode and decode routines that allow the transmission of binary files
over normal text based mail systems.
VULCAN NERVE PINCH
The CTRL-AMIGA-AMIGA reboot sequence.
WCS
Writable Control Store. This is the 256K of extra memory on the Amiga
1000 that is provided to hold the contents of the Kickstart disk. The
V1.1 and V1.2 operating system updates where distributed on disk.
WORKBENCH SCREEN
The default screen that appears when the machine first starts up. It's
titled "Workbench Screen" and may, or may not, contain the workbench
tool.
WORKBENCH TOOL
The icon oriented interface to AmigaDOS. This is normally started up
when the machine is booted via the "LoadWB" command. "LoadWB -debug"
can be used to start up with an invisible debug menu.
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|\ /| . Ack! (NAK, EOT, SOH)
{o O} .
( " ) bryce@cogsci.berkeley.EDU -or- ucbvax!cogsci!bryce
U "Success leads to stagnation; stagnation leads to failure."ralph@mit-atrp.UUCP (Amiga-Man) (08/01/87)
An excellent job on the glossary, Bryce ! The language is clear *and* entertaining. Two very good qualities for technical writing. Now how do we make sure all new, budding Amiga Programmers get a copy ?
kent@xanth.UUCP (Kent Paul Dolan) (08/02/87)
In article <1427@mit-amt.MEDIA.MIT.EDU> ralph@ATRP.MEDIA.MIT.EDU (Amiga-Man) writes: > >An excellent job on the glossary, Bryce ! >The language is clear *and* entertaining. Two very good qualities >for technical writing. >Now how do we make sure all new, budding Amiga Programmers get a copy ? Do like the folks in the newusers group, Bryce; post it periodically (quarterly plus significant updates would be great and surely wouldn't overburden the net!) Kent, the man from xanth.