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Path: informatik.tu-muenchen.de!kellerer From: kellerer@informatik.tu-muenchen.de (Ignaz Kellerer) Newsgroups: comp.sys.amiga.introduction,comp.sys.amiga.misc,comp.sys.amiga.programmer,comp.answers,news.answers Subject: Amiga FAQ (Frequently asked questions) (Part 1 of 4) Supersedes: <AmigaFAQ-1-824230821@informatik.tu-muenchen.de> Followup-To: comp.sys.amiga.introduction Date: 9 Apr 1996 16:00:25 GMT Organization: InternetNews at TUM, Technical University of Munich, Germany Approved: news-answers-request@MIT.EDU Distribution: world Expires: Sunday, 12 May 96 18:00:24 MESZ Message-ID: <AmigaFAQ-1-829065624@informatik.tu-muenchen.de> Reply-To: kellerer@informatik.tu-muenchen.de (Ignaz Kellerer) NNTP-Posting-Host: hphalle3g.informatik.tu-muenchen.de Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Summary: Frequently asked questions on the Amiga. New users should read this! Originator: kellerer@hphalle3g.informatik.tu-muenchen.de Posted-By: auto-faq 2.4 Archive-name: amiga/introduction/part1 Last-modified: Tuesday, 9. March 1996 Posting-Frequency: ever fourth week Frequently asked questions (FAQ) concerning the Amiga. [1/4] ------------------------------------------------------------ Below you find a list of frequently asked questions. It should especially be for new users but perhaps experienced users may find something too. This is part 1, the second begins with chapter 4, the third with chapter 5, the fourth with chapter 7. It is in Ascii format to be easily read by everyone. It is also available in AmigaGuide, Dvi and html (for WWW servers) format as part of the Amiga-FAQ archive. (File docs/misc/AmigaFAQ.lha on any Aminet site) Please note the following: - Changes since the last posting are marked with a ! changed this line/section, respectively + added this line < removed something before this line - An index is at the bottom of part 4. If this still doesn't help: E-mail me, probably I can include an answer into the FAQ. - Suggestions, contributions, critics and beer bottles are very welcome. :-) Send them to: Ignaz Kellerer Georg-Habel-Str. 11 81241 Muenchen (Germany) Tel. (+49) 089 / 885147 Internet: kellerer@informatik.tu-muenchen.de ===========================(Cut here)========================================= Amiga-FAQ ********* This document lists some frequently asked questions and tries to give answers. Its intention is to help new users and to reduce the amount of news that most experienced users don't like to read anymore. Please notice that there are many questions that aren't answered yet, even more: Whole sections that remain empty! I feel that I cannot give satisfying answers. So it's your turn: Fill the gaps and tell me what i should include into this document! Disclaimer 1 CPU, Custom chips, RAM and other stuff 1 What are 68EC020, 68EC030 and 68LC040? 2 What's an FPU? 3 Can I use a 3.5' HD in my A1200? 2 The Operating System 1 Can I use another Kickstart than the builtin? 2 The Graphical User Interface 3 What is MUI? 1 Icon collections and Backgrounds 4 What is the Amiga equivalent of . (Current directory)? 5 The PIPE: queue-handler 1 Using PIPE: in a standard AmigaShell environment 2 The Pipe command 3 Pipe command support in AmigaShell 4 Quick usage guide 5 Related things 6 Troubleshooting 6 ARexx, the program control language 3 How about Graphics? 1 What are chunky and planar displays? 2 What is doublebuffering? 3 What monitors will work on my Amiga 1200/4000? 4 How do I switch between PAL and NTSC? 4 Programming 1 What documentation do I need as an Amiga programmer? 2 What is CATS? 3 Where do I get the Amiga includes? 4 How do I become a developer? 5 What compilers (assemblers) are there? 6 Those never working Esc sequences! 7 Is it possible to use AmigaBasic on the A1200? 8 How do I localize my program? 9 How to obtain a pointer to a console's window 10 What are pragmas? 11 My Compiler/Linker is complaining about missing symbol xxx. 12 Where do I find the function xxx? 13 The GNU C compiler: general information and installation 1 Current Version 2 Requirements 3 Authors 4 Sources for Gcc 5 Inline Headers 6 Amiga Libraries 7 Installation 8 Compiling 9 How to get help 5 Applications 1 Text Editors 2 What word processors are there? 3 Desktop Publishing 4 What is TeX and where can I get it? 5 Are there any Postscript interpreters? 1 Amiga Font Formats 2 Frequently Requested Amiga Fonts 3 Commercial Font Sources 4 Non-Latin fonts on the Amiga 5 Amiga Font Installation 6 Amiga Font Utilities 7 Making Outline Fonts 8 Problems and Possible Solutions 6 How to deal with Non-Latin texts? 1 Japanese editors and viewers 2 Chinese text viewers 6 Connecting your Amiga to the world 7 Emulators 1 Can I run Unix on my Amiga? 2 Is it possible to use the Amiga as X11 terminal? 3 Is there a way to start MS-Dos programs? 4 How to mount MsDos-formatted Syquests on Amiga 8 Miscellaneous 1 Is there any unix version of LhA? 2 What are files ending with ...? 3 Is there a Stacker-like utility to pack my hard drive? 4 Where do I get Fish disk xxx? 9 Where and how do I get software and other informations? 1 Files and databases on freely distributable software 2 A collection of tests 3 Getting files from a FTP server 4 Getting files from a Mail server 5 Getting files from a mailbox 6 The Fish PD series 1 The Amiga Library disks 2 The Fresh Fish CD-Roms 7 How do I Read and write MS-Dos disks? 8 How do I split large files? 9 Discussing things 10 Other FAQ's The Amiga-FAQ archive Contributions Credits Index Disclaimer ********** This document is Copyright (C) Ignaz Kellerer Georg-Habel-Str. 11 81241 Munich (Germany) Tel. (+49) 089 / 885147 Internet: kellerer@informatik.tu-muenchen.de Permission is granted to make and distribute verbatim and modified copies of this document following the terms of the "GNU General Public License" provided the copyright notice and this permission notice are preserved on all copies. The author gives *absolutely no* warranty that the answers given here are correct or usable. Many of them were contributed by other users and I cannot even make marginal checks. If you think that something should be changed, please tell me. Suggestions, contributions, new answers, critics, flames (oh, how I like this `nil:' :-) are rather welcome. See Contributions. 1 CPU, Custom chips, RAM and other stuff **************************************** This chapter contains questions concerning the Amiga-Hardware. 1.1 What are 68EC020, 68EC030 and 68LC040? ========================================== Motorola, the company producing the 680x0 family offers crippled versions of their processors. They are a little bit cheaper than the originals, that's why Commodore decided to build the 68EC020 into the A1200 and the 68EC030 into the A4000/030. The difference between the 68020 and the 68EC020 is that the latter can address just 16Mb of memory. That's why the A1200 cannot have more that 10 Mb RAM. In most cases you will not notice the difference. This is not the case for the 68EC030: Many owners will notice that the 68030 has an MMU and the 68EC030 doesn't have. There are some important programs depending on an MMU, for example Enforcer (a debugging utility), GigaMem (a program to emulate virtual memory) or all current Unix versions (see Unix). Other Amigas than the A4000 and the A3000 need an additional processor card using a 68030 or 68040 or 68060 to run these. Finally the 68LC040 is a 68040 without FPU. See FPU. 1.2 What's an FPU? ================== The first 680x0 processors (upto 68030) could process integers only. Floating point operations had to be emulated by the software. An FPU is a chip (or part of a chip) that can process floating point operations, a mathematical coprocessor. One separates three FPU types on the Amiga: The 68881, 68882 and the 68040's internal FPU. The 68882 is up to 1.5 times faster than the 68881, because it is splitted in two parts: A conversion unit (the FPU's are using an 80 bit format internally) and the arithmetic unit. The 68040's internal FPU adds a pipeline, but misses the trigonometric instructions of the others. These are still emulated by the software, 68040.library for example. Special programs (Raytracing, DTP, Mathematics, TeX) are offered in a special coprocessor version which are up to 50 times faster than the original versions. Michael Kaiser (kaiser@ira.uka.de) 1.3 Can I use a 3.5' HD in my A1200? ==================================== Many people would prefer to use a 3.5" instead of the smaller 2.5" drives as the former are much cheaper. This is possible, but you need a special cable to connect the drive to your IDE controller. Additionally you should put some isolating material between the drive and the main board. Some people report termic problems but I did not notice anything. Some dealers offer a set which contains the cable, isolating material and for about 20$. See the magazines for more information. Thomas Schuh (thomas@stepout.tynet.sub.org) If you are going to install an IDE-harddisk, regardless if 2.5" or 3.5", you should always consider that the it may not work flawlessly, if the drive and ROM-version have not been tested and approved by Commodore. Regarding the A1200, one should also remember that this Amiga has not been designed to hold 3.5" harddisk drives. The 2.5" drives, which are mainly thought for portable computers, may have some advantages (for example in power consumption, heat emission or shock resistance) that could pay off because of the small keyboard case of the A1200 and the limited power supply. With the larger 3.5" drives, ventilation inside the computer might also be disturbed. If it is necessary to remove some shielding inside the A1200 to make the drive fit inside, even radio interference may occur. To sum it up: if 3.5" harddisk drives could really be used in the A1200 without any problems, you could be sure Commodore themselves wouldn't have used the slightly more expensive 2.5" drives in the A1200-HD. 2 The Operating System ********************** This chapter handles questions concerning the operating system, Kickstart as well as the Workbench. 2.1 Can I use another Kickstart than the builtin? ================================================= First let's drop some words on the Kickstart's Copyright: This belongs to Commodore, you *must not* use Kickstarts, without the right to do it! Especially it isn't allowed to make an image of anyone else's Kickstart and run this on your own Amiga. (I even doubt that it is allowed to do this on your own Amigas, if you have more than one.) But of course it is possible and allowed for some people, developers for example. There are two different ways, a hardware solution and a software solution. The former is to buy a card which can hold two or more Kickstart ROMS and allows to select between when the System is booting. The software solution needs a program (softkicker) and an image of the ROM. The softkicker allocates RAM, loads the ROM image into the allocated memory and reboots. Of course you have less RAM after the Reboot: 256Kb when running Kickstart 1.2 or 1.3 and 512Kb for Kickstart 2.0 or higher. There are different Softkickers, some of them needing a MMU (see 68EC0xx). I recommend SKick 3.43 (Aminet, directory `util/boot') because it doesn't need a MMU and supports many different Kickstarts. It is rather easy to create the ROM image using the following program: #include <stdio.h> #define kickorig 0xf80000 /* 0xfc0000 for Kick 1.2 und 1.3 */ #define kicklen 0x080000 /* 0x040000 for Kick 1.2 und 1.3 */ void main(int argc, char*argv[]) { FILE *fh; if ((fh = fopen("kickstart.file", "w")) != NULL) { result = fwrite(kickorig, kicklen, 1, fh); } fclose(fh); } 2.2 The Graphical User Interface ================================ Die standardmΣ▀ig mitgelieferte OberflΣche "Workbench" ist nur die Grundlage zum Aufbau einer guten, angenehmen OberflΣche. Zu diesem Zweck gibt es zahlreiche Tools, die den Anwendern das Leben erleichtern. Einige von diesem findet man auf dem Aminet in den Verzeichnissen `util/#?/'. 2.3 What is MUI? ================ MUI is a set of shared libraries which are used to build a comfortable GUI (`Graphical user interface'). The general idea of MUI is that the programmer determines only the logical structure of the GUI and the look (Font, Size, Windows on Workbench, Public Screen, own Screen, ...) is determined by the user only. From the programmers point of view using MUI is simpler than `gadtools.library' but much more powerful. On the other hand MUI interfaces are slower than GadTools-Interfaces, especially on old 68000 machines. MUI is found in two archives, one for developers only and one for users. Source: Aminet, `dev/misc'. 2.3.1 Icon collections and Backgrounds -------------------------------------- The standard icons aren't beautiful, indeed. But there do exist some beautiful icon collections. I know of `MagicWB' and `NewIcons'. `MagicWB' is Shareware. The icons are drawn beautiful in pastel with every known trick. You also get a lot of good backgrounds which beautify workbench windows and MUI programs. Fine and good readable fonts replace the clumsy topaz8 font. You also get good icons for the ToolManager. You can find a test version of MagicWB on Aminet. `NewIcons' is Freeware. The icons do have relative intensive colors and are drawn as three dimensional objects floating slanted in space. You can find NewIcons on Aminet, `util/wb/NewIcons.lha'. *F:* How do I turn off the "Gag" of MagicWorkbench (the intro which appears sometimes during booting)? *A:* In S: should be a file called `mti.data'. Delete it. *F:* How can I create NewIcons? *A:* The author of NewIcon currently works on an IconEd. Until then, Iconian 2.9x (I3) is the only way to create NewIcons. *F:* How can I prevent MagicWorkbench Icons to appear in incorrect colors? *A:* Register MagicWB 2.0, it contains a tool which patches the palette, or get one of the different tools from Aminet. *MagicColors* *ShoveColors* Its a good program, you can find it in Iconian, PictIcon or `Aminet:util/wb/'). 2.4 What is the Amiga equivalent of . (Current directory)? ========================================================== The AmigaDOS equivalent for the . representing the current directory on Unix and certain non-reentrant interrupt handlers is the empty string, which is written as "". Example: COPY S:Startup-Sequence "" copies your Startup-Sequence to the current directory. There is some FD software available to patch a Unix-like interpretation of . and .. into the AmigaDOS, including, but not limited to, Martin Scott's UnixDirs. (Aminet, `os20/util/UnixDirsII.lha' or Fish-disk 837) Arno Eigenwillig (arno@yaps.dinoco.de) 2.5 The PIPE: queue-handler =========================== In the AmigaOS release 2.04, a new handler for passing data between programs was introduced. This handler is called `L:Queue-Handler', better known as the `PIPE:' device. `PIPE:' implements a true `pipe' familiar from UNIX systems. Its function is to pass the output of one program to another program as input. You can chain several programs together using multiple pipes. The advantages of using pipes are: 1. No need for a lot of RAM to keep the temporary files, or, no need to slow things down by storing temporary files on the HD. 2. Faster operation since the intermediate data doesn't need to be stored anywhere between programs. The `PIPE:' device differs from the UNIX pipes in two important respects: 1. It is a device, so the input and output of the programs doesn't need to be a redirected standard output, although that is the general case. You can also use `PIPE:' instead of files, with two restrictions; you can not read a directory from `PIPE:', and the `PIPE:' `file' can not be `seeked' in. 2. It does not support a flush operation. If all of the data written in a `PIPE:' device is not read out, it will stay there, buffered. Thus you must always `empty' a pipe before closing it. 3. Because of the above, if unread data exceeds the size of the `PIPE:' internal buffer, the program writing to the pipe will `block' (that is, suspend operation) until the data is read. See below on how to manually flush a pipe. The PIPE: handler name syntax is `PIPE:name/bufsize/bufnum', where `name' is the name for the pipe channel. Using names you can have several simultaneous pipe operations. The optional arguments `bufsize'and `bufnum' specify the size and number of the buffers used by `PIPE:'. Normally, you would just use `PIPE:name'. The default buffer size of `PIPE:' is 4096 bytes, and the number of buffers (ie. channels) is unlimited. Osma Ahvenlampi (Osma.Ahvenlampi@hut.fi) 2.5.1 Using PIPE: in a standard AmigaShell environment ------------------------------------------------------ First, make sure `PIPE:' is mounted. You can do this by giving the command 1> Mount PIPE: in a Shell window. On an AmigaOS 2.1+ system, `PIPE:' is normally mounted on startup by placing the mount entry file `PIPE' in the drawer `DEVS:DosDrivers'. In an AmigaShell window, give the commands: 1> Run List SYS: >PIPE:Listoutput 1> More <PIPE:Listoutput (1) These two commands list the contents of the `SYS:' volume to a pipe and then type it in the Shell window. You could also use: 1> Run List SYS: NOHEAD >PIPE:Listoutput 1> Run Sort PIPE:Listoutput PIPE:Sortedoutput 1> More <PIPE:Sortedoutput Notice that you need to `Run' all the programs except for the last one. This is so that you can get them all running simultaneously. You could also use several Shell windows, or any other way of running all the programs at the same time. Also this might not work if `More' isn't the standard Commodore AmigaOS 2.04+ More found in `SYS:Utilities'. In case you need to manually flush a pipe, for example because the program that was reading from it aborts prematurely, it can be done with the command: 1> Type PIPE:name TO NIL: ---------- Footnotes ---------- (1) Note that `1>' is the prompt AmigaShell gives when it is waiting for a command. The number varies, and the prompt can be customised to look completely different. It is not a part of the command. 2.5.2 The Pipe command ---------------------- As you can see, this is a somewhat difficult way of using pipes, needing a lot of typing especially compared to the UNIX pipes. There is a solution for that. Andy Finkel, a former Commodore software engineer wrote a command called `Pipe' (not to be confused with `PIPE:') that simplifies the use of the `PIPE:' device. Unfortunately, this command did not make it into the 2.04 release. However, Commodore has given the permission to distribute this, and a few other commands, freely. (Sources: Fish disk 673, Aminet, `util/cli/finkelshelltools.lha') For some reason Commodore did not include these commands in the later OS releases, although they work fine even with OS 3.1 (V40). Thus all users are required to get them from the above sources if they wish to use them. The Pipe command usage is simple. The commands to be run with their inputs and outputs piped together are given as arguments to the command, separated by the | (vertical bar) character: 1> Pipe List SYS: | More or 1> Pipe List: SYS: NOHEAD | Sort IN: OUT: | More Notice how Sort needs `IN:' and `OUT:'. These devices don't actually exist, but the Pipe command simulates them with the PIPE:. This is necessary because C:Sort can not use the `standard IO', but insists on files. The separator character | can be configured to be something else with the local variable __PCHAR. 2.5.3 Pipe command support in AmigaShell ---------------------------------------- There is a little known and quite useful undocumented feature built in the 2.04+ AmigaShell, that is, AmigaShell knows about the `Pipe' command. By setting the local variable _PCHAR, you can use pipes without even entering the Pipe command. AmigaShell will prepend it on the command line automatically if it sees the pipe separator command specified by _pchar on the command line. Thus, after the command: 1> Set _pchar "|" (1) the above examples can be used like this: 1> List SYS: | More or 1> List SYS: NOHEAD | Sort IN: OUT: | More Those familiar with the UNIX pipes will notice how the usage is very similar to the UNIX pipe usage. ---------- Footnotes ---------- (1) The quotes around the vertical bar are important, to avoid AmigaShell interpreting the command as an attempt to use PIPE:, if _PCHAR is already set (for example if the Shell is started from within another one). 2.5.4 Quick usage guide ----------------------- 1. Get the ShellTools archive from the Fish disk 673, or from Aminet, `util/cli/hacks204.lha'. 2. Install the commands in this archive in your Shell search path, preferably C:. 3. Put the command `Set _pchar |' in your `S:Shell-Startup' file. 4. Restart your AmigaShell so that it reads the `S:Shell-Startup'. 5. Try `List SYS: | More' 6. Read the ShellTools documentation and experiment. 2.5.5 Related things -------------------- The variable _mchar is used to separate one command from another in a shell line. So, after the command: 1> Set _mchar ";" you can put more shell commands into the same line, separated from each other by `;'. 2.5.6 Troubleshooting --------------------- *Q:* When I try the command `List SYS: | More' I get an error PIPE: Unknown command I have `PIPE:' mounted, what's wrong? *A:* AmigaShell is referring to the command `Pipe' in the error, not the `PIPE:' device. You haven't installed the commands in the ShellTools archive. *Q:* I get a requester that says Please insert volume PIPE: in any drive when I try any of the command examples. *A:* `PIPE:' is not mounted. Try `Mount PIPE:'. If that doesn't work, refer to your AmigaDOS manual or a friend that knows how to mount devices. *Q:* When I try any of the examples the More window pops up but nothing is shown/I get an error afterwards/More pops up a file requester. *A:* You are not using the standard AmigaOS `More' command. Either use another name or install a command that supports pipes. Possibilities are the C= More, Less, or Most for example. *Q:* With use of PIPE:, sometimes characters get lost. What happened? *A:* Up to OS 3.1, the queue-handler has some bugs which don't allow a really foolproof transmission of data. A compatible replacement for the queue-handler can be founbd on Aminet, `util/sys/HWGQueue.lha'. *Q:* None of these happen but it still doesn't work as you described. *A:* Are you using OS 2.04 later? Are you using the standard AmigaShell? Try with all extras disabled. 2.6 ARexx, the program control language ======================================= *Q:* I want to send an ARexx command through CLI or through a shell script, but that (rx ADDRESS PORTNAME;COMMAND) doesnt work. *A:* You have to put quotation marks. (rx "ADDRESS PORTNAME;COMMAND"). It also prevents upcasing the portname when it should be lowercase. 3 How about Graphics? ********************* Graphics is one of the major strengths of the Amiga. Why don't we have more answers here? :-( 3.1 What are chunky and planar displays? ======================================== Simply put, the terms `chunky' and `planar' (short for `bitplanar') refer to different ways of storing graphics information in a computer's memory. They are rather easy to understand, as far as things go, but incredibly difficult to explain: Computer images are arranged as a grid of pixels, each of which can be thought of as a number representing the color number of the pixel, sort of like a paint-by-numbers scheme. For example, here's a simplified example image, in four colors: 00302132 The Amiga stores this image in a `bitplane' mode. That is, it is represented by several planes of bits (binary digits, 1s or 0s). This is a four-color image, so each color number could be represented by two bits. Therefore there are two bitplanes: 00100110 Here's bitplane 0 00101011 And here's bitplane 1 -------- Now, let's add them up, binary style: 00302132 Which is the final image. If the image was in two dimensions, it would truly be composed of bit planes. However, I'd need three dimensions to show multiple bitplanes overlayed, and therefore for simplicity we're working in one dimension (which is all we need). Now, there's another way of storing this image. How about if we localize the bit data in little chunks? 00 00 11 00 01 10 11 01 = 00302132 This is the principle of the `chunky' pixel mode. Both methods of image storage are perfectly logical, and no one can say that one is better than the other. However, there are certain technical aspects which cause certain advantages and disadvantages. First, if you've seen colored text scroll on your Amiga, you know there is a bit of "flicker" that arises. Specifically, what happens is that while the text is scrolling, its color temporarily changes to something completely different. What's happening is that the computer's moving several bitplanes of data while the raster (monitor electron gun) is sweeping across the screen. What that means is that, if the raster catches the data while it's being moved, you can end up with some bitplanes being moved and some not. What if we filled bitplane 1 in the example above with 0s? Instantly all the 3s become 1s, and the 2s become 0s! This is what causes "flicker" when certain colors are scrolled. By contrast, if a chunky pixel display is caught while scrolling, all we see is a partially-scrolled image; the colors are preserved (since their units are the small ones). That's a disadvantage to planar pixels, but what about chunky pixels? Well, recall that a computer organizes information in terms of 8 bit bytes. These groups are static; you cannot decide to all of a sudden organize data in terms of three bytes or something! Therefore, when using chunky pixels, things get complicated if we decide to use a nonconvenient number of bits per pixel. In practice, the 8-bit (256-color) mode, and 24-bit (16 million color) modes are the most common candidates for chunky pixel displays. Finally, certain effects can be accomplished with the different systems. Bitplanar mode is particularly useful for things like shadows (where an extra bitplane is set with 1s instead of 0s), and chunky mode is great for perspective and "mapping" (since the data for each pixel is localized in a single "chunk"). The latter advantage makes chunky pixel mode really great for games, and is what made Wolfenstein 3-D possible. We all know that Amigas use the bitplane system for storing images. However, the Macintosh and PC(VGA) both use chunky pixel modes. While we can optimize our RAM usage with "bizarre" modes like 8- and 128-color, they gain the advantages of non-flicker scrolling, and the programming simplicity of just writing a byte where you want the pixel to go. The difference between the two modes becomes problematic in things like emulation. EMPLANT has a "chunky to planar" routine which it uses to convert a Macintosh display into an Amiga one. "Chunky to planar" routines are also useful for getting chunky-inclined things to run on Amigas (see TMAPDemo, rotdemo). On a side note, there was some confusion as to what EMPLANT used the MMU for with regard to chunky to planar. The MMU itself is incapable of performing the algorithm for the conversion; rather, it is used to detect what portions of the display memory are updated from the Mac side, and therefore the processor is saved from having to perform the chunky to planar conversion for the entire display. I sincerely hope that helped clear up most of the mystery concerning the terms "Chunky" and "Planar"! (Joseph Luk, jluc@eis.calstate.edu) 3.2 What is doublebuffering? ============================ Don't be ashamed if you haven't a clue as to what this is. It's rather simple, really. Imagine you wanted to animate something by drawing out each frame. Now imagine you had only one piece of paper. Even if you drew pretty fast, it would be difficult to see what the animation looks like because you'd have to erase the frame you just drew, in order to draw the next one! What if you had two pieces of paper? Why, then, you could see the difference between two adjacent frames. First you'd draw your first frame on the first piece of paper, then you'd draw the second frame on the other piece. Then you'd erase the picture on the first piece of paper, and draw in the third frame. Then you'd erase the picture on the second piece of paper, and draw in the fourth frame, and so forth. This is the principle of doublebuffering. The computer shows you the picture it just drew, then turns around and draws the next one. It then swaps the picture in front of you with the one it just drew, and repeats the process. The result is a smooth animation, because you never need to see the computer draw; all you see is each finished product. (Joseph Luk, jluc@eis.calstate.edu) 3.3 What monitors will work on my Amiga 1200/4000? ================================================== Monitors can be classified after the horizontal scan frequency they require. TVs, as well as C='s 1084 monitor, need frequencies around 15 kHz. VGA/SVGA need approx. 30 kHz. Multisync monitors can take many frequencies. In short: You can use any monitor you want with an A1200. BUT: - If you use a regular VGA/SVGA monitor, you can only use a few display modes (like DblPAL, DblNTSC and/or Productivity). I.e. (320|640) x (256|512|1024) for DblPAL. This is great for Workbench and all "serious" utilities (DTP etc), but don't expect any games to work... they don't use your preferences, just take over the machine and assume a 15 kHz monitor. Also, you cannot utilize the "Early Startup Control" screen (you know, disable cache, and that stuff), which also requires a 15 kHz monitor. Furthermore, VGA monitors don't have speakers. And the VGA-type modes don't support Genlocks. But for a lot of "serious" work, a VGA monitor is quite adequate. - You already know what happens with a 15 kHz monitor; the flickering in Interlace mode. A small tip: Try to use NTSC instead of PAL. This increases the refresh rate from 25 Hz to 30 Hz, at the expense of lower vertical resolution (482 lines maximum). The NTSC and PAL modes aren't as bad as many people think. If your monitor has a lot of phosphorous (long afterglow), PAL Laced can be quite OK, and it gives you a resolution of 1448x566 in SuperHiRes. That's the highest resolution currently supported on AGA Amigas, in _any_ display mode. - A Multisync gives you the best of both worlds. The 1940 and 1942 monitors from C= are quite OK, although rather cumbersome to use... The h/v size and offset must be set manually each time you switch display mode. (1) The 1960 monitor doesn't have this problem, but it's a bit more expensive. For a VGA/SVGA or Multisync monitor, you'd need a little shiny box which gives you the standard 15-pin "D" connector. It costs around $15. There are other alternatives... like the "AmiVGA" box ($50 or so), which I think is a cheapo version of the Flicker Fixer. (But it's really a shame to use this on an AGA Amiga.) Also, you can get a VGA monitor, and hook up your TV to the composite or RF port on the Amiga - one monitor for games, one for serious stuff. (Per Espen Hagen, per.e.hagen@ffi.no) ---------- Footnotes ---------- (1) A patch is available on Aminet for Kickstart 3.0 to do this without manual actions in the file `os30/util/Monitor30Patch.lha'. 3.4 How do I switch between PAL and NTSC? ========================================= PAL and NTSC are two different video standards, the former being European, and the latter being American. PAL has a slightly taller screen (256 lines non-interlaced, non-overscanned) as opposed to NTSC (200 lines), so if you see the bottom portion of a program's screen getting cut off on your American machine, chances are the program was written for PAL, and is running on your shorter NTSC screen. PAL and NTSC differences are somewhat less important to European users; since their machines default to PAL, running an NTSC program is no more than a minor annoyance having the screen only appear in the top portion of the display. Therefore, for us NTSC folks, switching into PAL mode becomes important to avoid loss of some picture on Euro Demos, etc. First, the most common misconception about switching between PAL and NTSC is that you need a Multiscan or special monitor for such a purpose. Not so! Just about any monitor can handle the minor signal difference between PAL and NTSC (50Hz vertical refresh versus 60Hz). The 108x, 19xx, and 20xx series, and even most TVs, can display both PAL and NTSC. Sometimes it is necessary to perform minor tweaking of vertical hold and/or v. size on your monitor to achieve full display, though this is trivial. What IS needed to switch between PAL and NTSC in software, is a "Fatter" (1MB) Agnus or better. If your system has more than 512K of CHIP RAM (use the avail command to find out) you have this chip. If you do not, ou can still construct a hardware switch (see below). The following directions assume you're an NTSC user who wants to switch into PAL mode, but the procedure for going from PAL to NTSC is much the same. The most common use of switching into PAL is for self-booting games, demos, etc. The best way to accomplish this on pre-3.0 systems is to use Chris Hames' Degrader program (most recent version: 1.30). Once you have procured this program, the switch is as simple as selecting "50Hz", and "50Hz System", then installing the program's ROMTag (little program that runs at boot-time) by pressing the "Survive Reset(s)" button. AmigaDOS 3.0 added a PAL/NTSC switch feature to its Boot Menu, and all you need to do in order to access this is hold down both mouse buttons as the computer boots. Select Display Options, Display Mode/PAL, and then Boot. If the program still fails to go into PAL mode (Zool is one I've found), you may wish to get Degrader anyway and try that. Software PAL/NTSC switching is easy and painless. Some people have gone even further by installing hardware PAL/NTSC switches. This results in a system which even the most nasty hardware-banging programs can't bring to its original configuration (if it has been switched). The procedure is simple - most Amigas have jumpers already - but beyond the scope of this document. Therefore, if your screen is too short or cut off, seek the different screen mode. You'll "see new horizons", literally! (Joseph Luk, jluc@eis.calstate.edu) (1) ---------- Footnotes ---------- (1) PAL/NTSC switching with a MultiSync monitor is possible on 2.0+ and easily accomplished by moving the PAL monitor type to (or NTSC, as applicable, I have them both in) the Devs/Monitors drawer (from the Storage/Monitors drawer), reboot, then go into the Prefs drawer and select the ScreenMode program. You will see at least two PAL modes available (PAL and PAL Interlaced). Simply select one of the (usually non-interlaced for demos) and select "Use". All windows on the Workbench will close, the video mode will change, and then the windows will reopen - that simple! Allen J. Newton, anewton@alturia.abq.nm.us