AMOS PD CD

home *** CD-ROM | disk | FTP | other *** search

/ AMOS PD CD / amospdcd.iso / aminet / amos136.dms / amos136.adf / About_AMOS_1.36 < prev next >

Wrap

Text File | 1993-03-15 | 55KB | 1,485 lines

----------------------------------------------------------------------------- AMOS BASIC VERSION 1.36 UPDATER By François Lionet AMOS (c) 1990 / 1991 / 1992 / 1993 Europress Software Ltd. ----------------------------------------------------------------------------- Important copyright notes --------------------------- The AMOS Basic 1.36 Updater is public domain. You can (and you are encouraged to) copy and distribute it freely. It does not mean AMOS Basic itself is public domain. Copyright remains on the interpreter, and on the updated version. You need AMOS Basic V1.1, V1.21, V1.23, V1.3, V1.31, V1.32, V1.34 to make the adaptation. ------------------------------------------------------------------------------ Move the mouse pointer to read the text. ------------------------------------------------------------------------------ Foreword. ------------------------------------------------------------------------- Welcome to a new update of AMOS! This update of the software brings you only one new thing, but a big one: it works on a AA machine. You can now start AMOS from a AA workbench, and flip between them as normal. If you own V1.34 of AMOS, you will find that this is the only modification to the software. If you intend to compile programs and make them available to the Amiga community, make sure that you compile them with Compiler V1.36, which also works under the AA chipset. The V1.36 Compiler Updater is also available in PD. If you own a previous version of AMOS, this version will bring you a much safer environment, better accessories: a lot of work has been done between V1.2 and V1.34 of AMOS... Make sure you read all the documentation to receive all the information about the new instructions... All the best! François 01/02/1993. Contents. --------------------------------------------------------------------------- * Enhancements to V1.34 * Bugs removed from V 1.31 * New instructions in V 1.36 * Manual main bugs * Safe AmigaDos EXECUTE function * Time and Data procedures * Modifications up to V 1.2x - Bob flipping - Serial port (modified since V1.23!) - Multi-tasking - Folders - Interlace - Other bits - Converting your 1.2 .Env file to 1.3 Introduction. ----------------------------------------------------------------------------- AMOS Basic has gone through a number of changes during the course of its existence. Rather than rest on our laurels, we've steadily updated the system to include many new features suggested by AMOS users. Incredibly enough, we've placed these improvements on the public domain. Special updater discs are available from the official AMOS PD. library or your local PD. library. So whatever your version of AMOS Basic, you can upgrade to the latest system for the price of a disc. Here's a list of the versions of AMOS Basic to date: AMOS 1.1 The original! AMOS 1.2 This included several new commands such as a BANK SWAP. There was also a whole new set of SPRITE flipping routines introduced which allowed you to display a single image in several orientations. The file-selector was completely reworked, and allowed you to change the current disc by pressing the RIGHT mouse button and simply clicking on the new device name with the mouse. The UP/DOWN arrows were repositioned at the top of the scroll bar for maximum speed, and the PARENT button was repositioned to the far left corner and reduced in size. AMOS 1.23 Added the SERIAL extension, SPRITE compactor and procedure locking utility. AMOS 1.3 This version comes with the compiler and includes a range of turbo-charged Bob and screen copy routines written by Gary Symons. These optimise the performance of commands such as SCREEN COPY and PASTE BOB/ICON, leading to dramatic speed improvements in many games. AMOS 1.31 Only minor internal modifications done since version 1.3. AMOS 1.34 By cleaning up the code dramatically, we've been able to get rid of many little but annoying problems. It also includes major enhancement to the music routines. AMOS 1.36 AMOS now works on a AA machine. Improvements (from 1.31). ------------------------------------------------------------------------- * AMOS now works on a AA machine. You can as usual flip between a AA workbench and the AMOS Program. The new method used on a AA machine makes it impossible to work under interrupts. That's why you will discover that it Amiga-A does not respond when a disc activity is taking place, but only when disc access is over. The new method used on a AA machine makes it impossible to work under interrupts. That's why you will discover that it Amiga-A does not respond when a disc activity is taking place, but only when disc access is over. * Versions.AMOS. This little program will explore the whole contents of your AMOS_System directory, and load the beginning of each file. It will look for a special string that contains the version number, and display it onto the screen. You will know at a glance all the version numbers of your programs! * The directory system has been totally re-written. You can now, safely use DIR$= to set the current directory, and it does not leave a Lock as it used to. More than that, =DIR$ does not crash any more when it cannot find a disc in the drive. The file selector now automatically sets the dir to the current path when you select a file. Note that the SET DIR button still works, if you want to quickly set the directory, without loading a file. To sum-up, AMOS now has one current path, automatically set by the file selector or by the DIR$= instruction. * Hexadecimal and binary tokenisation now stops on spaces. It makes possible to tokenise such a line: If A=$1234 And B=2 It was impossible before, as the A of "And" was used as part of the hexadecimal number! * AMOS now closes the workbench under 2.0. If you want to prevent that, you have to use the configuration program, in the SET EDITOR menu. New in version 1.36, the CLOSE WORKBENCH instruction will not have any effect if you choose not to close the workbench in the configuration program. More than just preventing AMOS from closing the workbench upon loading, it is preventing any AMOS program from closing it. You are now the master of your own Workbench! * The Requester now appear under AMOS on a 2.0 system. It does not crash as it used to sometimes under 1.3. The disc-inserted detection has been improved, it detects all disc-changes now. It also works with one option requesters. * The disk-font library only loads when you call it the first time. It means you may have to re-insert the Workbench disc upon running a new program, as you would do if it was using floating point numbers. * Load IFF accepts new colour palettes, with colours defined on 8 bytes, instead of 4 (this palette are saved by some new software). * Physical drives are now listed in the device list (in file selector and in =Dev First / =Dev Next). Some devices (like "Work:") are defined in both logical and physical list. You will find them twice in the list. This is normal! * Copy now works with ODD addresses, and ODD lengths. I should have done this improvement much sooner. * You can now recover from an "Out of variable space" error, it does not stop the program as it used to. All you'll have to do in this case, is free a couple of strings from memory. * Sound samples of any length are perfectly played. * Autoback 2 mode does not produce a flash in the bobs as it used to, sometime. It gives a much better display. On the other hand, pasting and printing in this mode will take one VBL longer than before. Bugs removed (from V1.31). -------------------------------------------------------------------------- * ICONS used to be in transparent mode upon loading, instead of being in replace mode, as stated in the manual. * CBLOCK did not work for blocs larger than 480 pixels. * The inactive mouse-zone (when the mouse pointer was exactly over the top of the horizontal slider, no keyboard input was processed) has been removed. * The disappearing line bug has been removed from the editor! * Def Fn does not crash any more with no parameters. * Set Rainbow does not crash with negative parameters in definition strings. * Error n instruction now reports errors over 50. * AMOS now saves Workbench icons properly, not all placed over each other, as it used to! * EVERY command works fine. At last. * PLOAD used to leave a lock in the system. * =DRIVE() does not display a requester if the device does not exist. This was really stupid, as this instruction was used to determine existing devices! * Music banks are now detected upon running. It means you can safely save them with the program. * Arrays now work fine when you access elements higher that 65536. * On Menu Proc used to block the machine under certain circumstances. * Bobs can now be displayed on VERY large bitmaps. * Marks did not work on A3000. * Opening procedures with errors within, used to position the cursor at the beginning of the text. * INPUT #x,A$(n) did not ask for a proper string space. The result in worse cases was a crash, as the incoming string erased crucial AMOS pointers. * Note on serial interface problems. A lot of users have reported to us problems when they were using the serial extension. Their programs used to work the first time, and crash on the next RUN. Amazingly enough, this bug does not come from AMOS, but from Commodore. Commodore released a few years ago a bugged version of the serial.device. Bad luck, this bugged version happened to be duplicated on our AMOS Master. At that moment we didn't realise this. As soon as we were made aware of the problem, we re-mastered the AMOS discs. But too late, some version of AMOS have got the wrong device. The updater will save a good version of the serial.device on the copy of your AMOS Master. New music instructions. ----------------------------------------------------------------------- The music extension has been considerably enhanced. We've listened to your requests: * Playing Soundtracker modules. SoundTracker is moving too fast for us. Every month or so, a new program pops up, with new instructions, making the SoundTracker converter obsolete. The SoundTracker converter works fine with modules up to NoiseTracker V2.0. Above this version, some effects may be badly converted. Anyway, you thought that this converter program was not a very good idea. That's why we have directly implemented a Tracker player in the music extension. The chosen one is "Startracker player", because it contains all the latest and main effects (today!), and it has the ability to play synthetic instruments. Here are the new instructions: TRACK LOAD "Name_Of_The_Module",Bank ------------------------------------ Load up a tracker module into a chip memory bank. It will of course it reserve the bank for you, and choose the correct bank size. If AMOS detects a Startracker synthetic instrument file (which must have a ".NT" extension appended to the file name), it will load it AS WELL into the bank. In fact you don't have to worry about it. TRACK PLAY [Bank],[Pattern] --------------------------- Plays a tracker module loaded into a bank. "Bank" is the number of the bank to be played. If omitted, it is the last loaded with the TRACK LOAD instruction, or upon running, bank number 5. "Pattern" is the first pattern to be played. Use this with caution, as NO CHECK is done on the number of the pattern. You can very simply crash the computer by giving a bad value. This parameter is intended to allow you to have more than one music in a tracker bank... TRACK LOOP ON / OFF ------------------- Enable or disable looping when the tracker music is finished. TRACK STOP ---------- Stops a tracker music being played. IMPORTANT NOTES: ----------------- The Tracker-playing instructions are implemented to give you a quick way of playing modules. It is not as powerful as the normal AMOS music system. For example : * Do not play a normal AMOS music while playing a tracker module, this can lead to unpredictable results. * Do not start any sample, or sound effect when a Tracker module is played. * A Tracker module uses and initialises all four voices, even if your music is only on 3 or 2. So do not play any sample on the other voices you think are free. They are not! * VOLUME instructions do not have any effect on the Tracker music, but =VU METER works fine with a Tracker module. ... if you want to make sound effects while a music is playing, then you should use the Soundtracker converter, and the normal AMOS Music system... Improvements in sample playing: -------------------------------- Here again we have listened to your complaints! You'll be happy to know that you can now play samples of any length, and that the small tick at the beginning have been removed. But much more than that, we have made it possible to play samples bigger than the actual memory of your Amiga, with the new double-buffer sample instructions. Floppy users : sorry, these new instructions will not be useable by you, but at a very low sample playing rate (like 4000-5000 Herz). The disc data output speed is just too low. Theses new instructions were designed mainly for CDTV and multimedia purposes... A working example of this instruction is given in the file "Sample_Double_Buffering.AMOS" you will find on your updated disc. I have commented this example very carefully, so that everything is clear to you. Before running this example, you have to create (or grab) a sound-sample, any size (preferable big), and copy it onto your hard-drive. You can easily understand that we could not put a 2 Megabytes sample on the updater disc! SLOAD File_Number,Length TO Address ----------------------------------- A new instruction intended to load parts of a sample, but it can be used in many other ways. This instruction is an extended BLOAD "File_Number" is the number of a file opened previously with the OPEN IN File_Number,"Name" instruction. "Length" is the number of bytes to load. If this number is bigger than the actual size of the file, then only the remaining bytes are loaded, without errors. You'll get an error if you try to load once more after the end has been reached. "Address" is the destination address. Of course, the memory must have been previously reserved. The advantage of this instruction, is that you can set the position of the file pointer with the POF()= instruction before using SLOAD. As you can see, this instructions can have a lot more usage than just loading samples... SAM SWAP Voices TO Address,Length --------------------------------- This instruction initialise the sound-swapping. The actual swapping will only occur when the actual buffer has been totally played through the speaker. The swap is done under interrupts, so you will not hear any tick in the sample. "Voice" is a bit pattern to define the voice concerned, just like in the SAM RAW instruction. "Address" is the address of the next buffer to play. Of course, it must be in chip memory. "Length" is the number of bytes to play. =SAM SWAPPED(Voice_Number) -------------------------- This function returns a boolean value (TRUE -1, or FALSE 0). It is the key function in synchronising double buffer players. "Voice_Number" is the number of the voice you want to have information about (0 to 3). Do not make mistake, is it NOT a bitpattern. It returns TRUE if the sample swapping has occurred, it means the new buffer you have initialised with the SAM SWAP instruction is being played at the very moment. It returns FALSE if not. Practically, you can only load a new part of the sample in the free buffer, when the SAM SWAPPED instruction returns you a TRUE value. It returns FALSE if the sample swapping has NOT happened. SAM STOP [Voice_Pattern] ------------------------ This simple instruction seems to have been forgotten in the instruction set since the beginning. The only way to stop a sample playing, was to use the PLAY instruction! "Voice_Pattern" is a bit pattern defining the voices to be stopped, like in the SAM RAW instruction. All voices will be affected if you omit it. NOTE: it is perfectly possible to have an AMOS music bank playing on 2 voices, and double-buffered samples playing on the last 2. (hey, but not a Tracker module, if you remember what I told you!) Other new instructions (from 1.31). --------------------------------------------------------------------------- * =COL(Bob) --------- Well, in fact, it is not a new instruction, but a good enhancement to the collision detection method. To detect a collision, I remind you, you have to use one of the collision detection functions (=BOB COL(), =SPRITE COL(), =BOB SPRITE COL(), =SPRITE BOB COL()). When this function returns a TRUE value, you have to explore the =COL() reserved array to find out which bob or sprite created the collision. The problem, is that you had to write a loop exploring sequentially all the COL() array. This was eating a lot of processor time. You could see certain games slowing down when some bobs were colliding. I wanted to do something to correct it. But what? The problem with AMOS, is that if I change the syntax or the behaviour of one instruction to please certain people, it may (and surely will) not be compatible with thousand of existing programs! So I found a -rather tricky- solution to this problem. =COL(Number) behaves normally if you send it a POSITIVE number as an argument, this keeps it compatible with all existing programs. If "Number" is negative, AMOS will first remove the sign, i.e. turn it into a positive number. Then it will explore the COL() array himself, and find the first non-zero value higher than -Number. Then it will not return TRUE or FALSE as it used to, but the actual number of the bob colliding. To get the next bob colliding, simply call it again with a this number, minus one.. Example, this small and fast loop, will give all bobs colliding with bob zero: B=Bob Col(0) BB=0 Repeat BB=Col(-(BB+1)) If BB Print "Bob";BB;" is colliding..." Endif Until BB=0 You can certainly remark that with this method, it is impossible to get the collision of bob number zero. That's why I say this was not perfect... =DISC INFO$("Name") ------------------- ...is a new instruction that returns information on any disc. "Name" is the name of a file or a directory of the disc you want to have information about. The string returned has the following form: "NAME_OF_THE_DISC:XXXXXXX" , where XXXXXXX is the free space on the disc. To get both, use this simple method: A$=DiscInfo$("Df0:") C=Instr(A$,":") N$=Left$(A$,C) F=Val(A$,C+1) Print "Name of the disc :";N$;" Free space:";F = PRG STATE (returns the current status of a program) ----------------------------------------------------- =PRG STATE This little handy function let you know how your program was launched. It returns three possible values: 0 : if your program was run under the AMOS interpreter. 1 : if your program was run under RAMOS run-only. -1 : if your program is compiled. Getting the system date and time. --------------------------------------------------------------------------- You will find on your updated disc a program called "GET_TIME.AMOS". This program includes two procedures to get the time and date from the system. Time. ----- Call the procedure, and you'll have in Param$ the current clock time under the following format: 00:00:00 _TIME$ Print Param$ ... 11:04:04 Date. ----- This procedure returns the current date in Param$: _DATE$ Print Param$ ... 21/06/1991 Safe AmigaDos EXECUTE. ------------------------------------------------------------------------------ It is perfectly possible to launch an external program from AMOS. But in order to do so, you have to know some of the AmigaDos internal functions. That's why you will find on your updated disc a small program with a procedure called _EXECUTE. Just transmit an AmigaDos command to this procedure, and it will launch it out of AMOS. To run an external program, use: _EXECUTE["RUN >NIL: <NIL: Program_Name.AMOS"] You can launch other CLI commands (like "Assign"). Of course if you want to see the display, you have to perform an AMOS TO BACK instruction. As the Amiga is a multitask machine, your AMOS program will go on running as well as the launched program. Of course the speed will be bit reduced, depending on the other program. Manual bugs. ---------------------------------------------------------------------------- This paragraph will just list some of the main errors found in the manual, like missing instructions. LLIST ----- This instruction does not exist, and never did! To print a program: - Mark the whole text as a block (CONTROL-A) - Go to the BLOCK menu, and select PRINT BLOCK. NO ICON MASK [number] (Remove the mask from an icon). ----------------------------------------------------- This instruction has simply been forgotten in the manual. It simply does the same job as NO MASK, but for icons. RAINBOW DEL [Number] (Delete on or all rainbows). ------------------------------------------------- Another instruction forgotten in the manual, but very useful when you want to get rid of a rainbow! "Number" specify the number of the rainbow to remove, or all if omitted. = TEXT STYLES (Returns the current font attributes). ---------------------------------------------------- This instruction is badly spelt in the manual. You must add an "S" to it! New instructions in V 1.3x / V 1.2x. ---------------------------------------------------------------------------- The following part of text grabs some parts of the previous "About_AMOS_1.3", found on the AMOS 1.31 PD. update. Anyway, you should (must) read it, as we have added some instructions that mysteriously disappeared from the documentation. Multi tasking improvements. --------------------------------------------------------------------------- MULTI WAIT (Force a multi-task wait vbl) ---------- MULTI WAIT To make effective multi-tasking programs, you must not grab most of the processor time, leaving only a limited amount of power for other tasks. MULTI WAIT does a MULTI-TASK wait vbl. You should use it in your programs main loop, when you wait for example, for a menu item to be selected. Note that you should not use this instruction to make accurate screen synchronisation as it is designed to multi-task. This instruction is not consistent at all! It may skip many VBLs, depending on the number of running tasks at the time. If you missed it elsewhere in the manual, Multitasking can be activated by pressing Amiga+A to flick between AMOS and the CLI or Workbench environments. This allows systems with at least 1 meg to run AMOS and programs like DPaint III at the same time! AMOS TO BACK (Hide AMOS from view and show the Workbench) ---------------------------------------------------------- AMOS TO BACK This will bring forward the Workbench display, allowing you to access other programs. AMOS TO FRONT (Switch AMOS to the display) ------------------------------------------- AMOS TO FRONT AMOS is forced back onto the display with this command, leaving the Workbench hidden. AMOS HERE (Report which task is on display) -------------------------------------------- AMOS HERE This returns TRUE if AMOS is currently displayed and FALSE if the Workbench is in view. AMOS LOCK (Forgotten instruction : Locks AMOS in front position) ---------------------------------------------------------------- AMOS LOCK This instruction first does an "AMOS TO FRONT", and then disable the AMIGA-A system. Use this instruction if you do not want people to know your program was written in AMOS. AMOS UNLOCK (Forgotten instruction : make AMIGA-A active) --------------------------------------------------------- AMOS UNLOCK Just restores the AMIGA-A Workbench/AMOS flipping. You may want people to stay under AMOS during certain parts of your program for example, to see your name (!) and then free them. Swapping banks. ------------------------------------------------------------------------- BANK SWAP number1,number2 ------------------------- This instruction will swap the pointers of the two banks. Useful if you want to turn an icon bank into a sprite bank. Example: Bank Swap 1,2 or have more than one music bank at the same time, for example: Bank Swap 3,5 Display-handling enhancements. ------------------------------------------------------------------------ LACED (Function to open an interlaced screen) --------------------------------------------- To open an interlaced screen use the following syntax: SCREEN OPEN 0,320,200,16,LACED [+HIRES] [+LOWRES] LACED is a function that returns 4. Important: As soon as one screen is opened with Interlace, all the other screens turn to interlace. The interlacing will only truly effect the screen actually opened with LACED. All the others will just have their vertical lines doubled on the screen to adjust to the special mode. Interlaced mode is perfect for displaying pictures, but animation runs at half normal speed. Games should not be written in Interlace! As soon as the last interlaced screen is closed the whole display returns to normal mode. Your TV monitor might not like lots of fast switching from normal mode to Interlace, so you are advised not to do this excessively. All normal operations are available in interlaced screens: Screen Offset, Screen Display and so on. The only problem that arises is due to interlacing being software driven in AMOS. The bitplanes are changed during the vertical blank and this particular interlace process is forbidden during copper list calculation. So if you have a large copper list (i.e.. four screens, one interlaced, and a rainbow), and have a copper calculation to do, the interlaced screen will display only half of the picture during the calculation. Nothing can be done to solve this, it is simply a limitation of the whole system. There are two extra screen commands in AMOS now. These allow a program to work out what type of display it is being run on: DISPLAY HEIGHT (Report how tall a screen can be) ------------------------------------------------- =DISPLAY HEIGHT This command returns 311 in PAL and 263 in NTSC. NTSC (Flags the type of display in operation) --------------------------------------------- =NTSC This returns TRUE if the system is in NTSC mode or FALSE if in PAL. Ideal for international software development! NTSC refreshes the screen at 60 times a second whereas PAL screens refresh at only 50 times a second. However, AMOS1.3 compensates for this and now music runs at exactly the same speed in PAL and NTSC AMAL also relies on the interrupt routine but is not slowed down to comply with PAL speeds. You must therefore be careful not to synchronise music and animations by just relying on the speed they run at. Check that an animation frame has been reached or the music has played a certain note. Using this technique you'll ensure the software executes at the right points on all systems. Requester enhancements. ------------------------------------------------------------------------- REQUEST (Generate a requester routine) --------------------------------------- REQUEST ON This will make AMOS use its own requester routine and is the default. REQUEST OFF AMOS will always select the CANCEL button of the requester if this command is used. The actual requester will not be displayed, so this is ideal for error trapping within a program. REQUEST WB This tells AMOS to switch back to Workbench's system requester. You'll come back to AMOS as soon as you have chosen one of the options. Note: If you don't load up the Requester (by deleting it from the extension list using the config file), the normal Workbench requester will be used for displaying messages. This does have a bad side-effect though, AMOS will seem to have crashed when a requester appears. If this happens you must simply press Amiga+A to return to the Workbench, answer the question and press Amiga+A once again to return to AMOS. It's only best to avoid loading the requester when memory is very low! Bob and sprite flipping commands. --------------------------------------------------------------------------- In a great number of games, the main character needs to animate left to right, and up and down. Up to now, you were obliged to keep in the sprite bank reversed copies of small animation sequences for the main character. As the main character usually has the best animation, you lose an enormous amount of space! For the game RanXerox, for which AMOS author François Lionet wrote the sprite routines, a flipping routine was developed which allowed just one copy of the main character to be kept in the bank. This routine has been enhanced and placed into AMOS. How does it work? Imagine your character is walking to the left and then back to the right. You would only have in your bank the image of him walking to the right. To display this right image, you simply refer to the image number in the bank as usual. To display the image reversed in the X axis (left walking image), you set bit number 15 of the image number to 1. Don't panic, you can simply do it with: $8000+Image number So: Bob 1,160,100,1 will display your character walking right, and: Bob 1,160,100,$8000+1 will display it walking left. The same principle is used for vertical reversing. For this, bit number 14 is used - add $4000 to the image number. To have a vertical and horizontal reversing, use $C000. The symmetry is a full symmetry: The hot spot of the bob is also reversed. For example, if we had put the hot spot in X under the feet of our character, the reversed version would also have it under his feet. So be careful if you set the hot spot on the top left corner on a bob, the reversed image will be displayed at the top left! You might say that $8000 and $C000 are a bit weird to use. We have provided special functions to give a better AMOS interface: =HREV(image) adds $8000 to the image =VREV(image) adds $4000 =REV(image) adds $C000 Use them in place of the hex values: Bob 1,160,100,10 Bob 1,160,100,HREV(10) Bob 1,160,100,VREV(10) Bob 1,160,100,REV(10) To allow easy use of the bob flipper in AMAL, we have implemented Hexadecimal evaluation. So you can use hex notation to refer easily to reversed bobs. If hex frightens you, just add $8000, $4000 or $C000 before all references in your AMAL strings. Example: Old AMAL string: "Anim 0,(1,2)(2,2)(3,2)(4,2)" New reversed string: "Anim 0,($8000+1,2)($8000+2)($8000+3)($8000+4)" or "Anim 0,($8001,2)($8002,2)($8003,2)($8004,2)" If you use a register to calculate the image number, do not try to modify the calculation itself, but only when you assign the register to the image. Old AMAL string: For R0=1 To 10; Let A=R0; Next R0 New one: For R0=1 To 10; Let A=$C000+R0; Next R0 How does the flip routine work? It is really important for you to understand how it works internally, so that you do not ask this system to do things it is not designed to do. The reversing system is designed to free memory before trying to be fast (although we would not mind if it was actually fast, would we?). Concessions had to be made to have it fast, and at the same time easy and powerful. The routine actually works right in the middle of the bank, and does not use any extra memory. The bobs are flipped during the update process, just before a bob is redrawn on the screen. AMOS looks to see if the image needs to be flipped in the bank. If it does, it is flipped and a flag is set within the bank. On the next update, if the bob image has not changed, it will not be flipped, thus saving a lot of time. If you understand the above, you will also realise one big limitation. It is not wise to use more than one flipped bob pointing to the same image. Let's see the next example: Bob 1,160,100,1 Bob 2,160,150,$8001 Bob 3,20,20,$4001 Bob 4,20,100,$C001 Update During the UPDATE process, AMOS will first draw bob number 1. No problem, it is in the right position. Then bob number 2 - AMOS needs to reverse it in X. Bob number 3 needs a Y and an X reversing (to put the bob back to normal in X!). Then bob number 4 needs an X flipping. On the next update, providing the bob's image has not changed, to display bob 1, AMOS will have to flip it in X and Y, then bob 2... As you can see, for each UPDATE, that is, every 50th of second, if the bobs move they need to be reversed! This will work, but will take a lot of processor time, and the animation will be disastrous. So the golden rule is, use the reversed bobs for objects alone on a screen (or be sure that normal and reversed images are not displayed at the same time on the screen). If you want, you can have two bobs like this - experiment! We told you before that this system was for use with bobs. Yes, it is totally automatic with bobs. But as it directly affects the sprite bank, you can also use it with sprites. When a hardware computed sprite is calculated, AMOS looks into the sprite bank and gets the image from it. If the image is reversed at that moment, the hardware sprite will display a reversed image. You can therefore have reversed hardware sprites using this method. But you cannot do this for example: Sprite 1,200,200,$8001 Pasting flipped bobs PASTE BOB also accepts reversed images. A simple trick to reverse an image in the bank without having to display a bob, is to PASTE the reversed image outside of the screen. Example: Paste Bob 500,500,$C000 This will reverse image 4 in the bank, without any output (and quite fast). Collision detection This is an important point, and you have to be very careful when you detect collisions with reversed bobs! The collision detection uses the shapes in the bank at the very moment it is called. Let's see an example that will never work: Bob 1,160,100,1 Do Bob 2,XScreen(XMouse),YScreen(YMouse),$8001 Wait Vbl Exit if Bob Col(1) Loop Why doesn't it work? We have two reversed images of the same definition in the bank. After the updating process, the image in the bank is left reversed. So the Bob Col instruction will take bob shape 1, the reversed image, and this will not work! So remember: Thou shalt never use collision detection with more than one reversed image on the screen! How is it coded into the sprite bank? Two bits of each images X Hot Spot are used to flag the flipping (at SPRITE BASE+6). Bit number 15 for X 0 if normal, 1 if reversed Bit number 14 for Y 0 if normal, 1 if reversed Before RUN and SAVE, the bank is restored to its normal state, so that it is still compatible with version 1.1. Block flipping The flip routine can also be used for blocks. HREV BLOCK (Flip a block horizontally) HREV BLOCK image Flips block number image horizontally. VREV BLOCK (Flip a block vertically) VREV BLOCK image Flips block number image vertically. Altering the Bob drawing order. ----------------------------------------------------------------------- PRIORITY REVERSE ON/OFF (Change the order in which Bobs are printed to ----------------------------------------------------------------------- the screen) PRIORITY REVERSE ON PRIORITY REVERSE OFF PRIORITY REVERSE ON, reverses the entire bob's priority table. This means that bob number 1 will be the first one drawn in front of all other bobs, 2 will come in second etc... This priority list is compatible with STOS. This instruction has another feature when used in conjunction with the PRIORITY ON command. The bobs are not printed from TOP to BOTTOM any more, but from BOTTOM to TOP! The highest bob on the screen will be displayed in front of the others. Squash a bob routine. ----------------------------------------------------------------------- This routine was originally written for a Fun School 3 program called Letters. Each letter in the alphabet is displayed as a single large sprite. This requires a total of 52 separate images, taking up a massive 110k of memory. Since only a couple of images are displayed at a time, most of this space is actually wasted. So a small routine was written to pack the unused sprites into a spare memory bank. This allowed us to compress the entire sprite bank into just 26k! AMOS Squash is now available on the public domain. Feel free to use it in any of your own programs. It's especially useful for the massive Level Guardians in an arcade game. These can be compressed into a fraction of their normal size, and can be instantly retrieved at the appropriate point in your program. Using AMOS Squash The packer program comes in two separate parts. The first program loads a sprite bank into memory and compacts your images. It can be found in the file Squash_a_bob.AMOS In order to use this routine, you need to perform the following simple procedure: Load a sprite bank from the disc using the file-selector. Enter the number of the first sprite you wish to pack. Enter the number of the final sprite in your list. Input the number of colours used by your sprite images. Choose a new memory bank to hold your squashed images. The squasher routine will now be executed and your selected images will be quickly compressed. After it has concluded, you will be given an option to save your compacted images onto the disc. Note that no colour information is saved with these images. So you may need to make a note of the current colour settings before proceeding any further. Once you've squashed your images, you can load them into your AMOS Basic programs with the help of three small procedures. These can be found in the file Squash_procs.AMOS and can be incorporated into your program using the MERGE command from the AMOS Editor menu. The squash routines are remarkably easy to use. The first stage is to load your original sprite bank from Direct mode and delete the images you have just compressed. Use a line like: Del Sprite start To finish This erases your old images from memory, saving you a considerable amount of storage space. You can now enter your packed images from the disc with the LOAD command: Load "images.abk" At the start of your program, you should initialise the compaction system with a call to the PBOB_INIT procedure: PBOB_INIT[bank,cols,max_x,max_y] Where: bank is the bank number containing your compressed images cols holds the number of colours max_x stores the maximum width of your images max_y holds the maximum height of your images The action of this procedure is to prepare a temporary screen for the squasher utility. Your images can now be unpacked as and when they are required, using a simple call to the PBOB routine. PBOB[source,dest] source is the number of the image to be unpacked. This is the original image number from the sprite bank. dest is the number of the new image you wish to install in the sprite bank. Choose the number of the last sprite in the bank plus one. Once you've installed your image into memory, you can animate it directly with the various SPRITE or BOB commands. PBOB can be called as many times as you wish. So the same image number can be re-used again and again. Finally, add a call to the PBOB_END procedure towards the end of your program. This will erase the hidden screen created by PBOB_INIT. Serial port commands extension. ------------------------------------------------------------------------- Welcome to the intriguing world of AMOS communications. The serial extension is intended for those of you who wish to transfer information between several different computers using the Amiga's serial port. The extension provides you with a total of 15 new commands. You can use these commands to create amazing multi-user games. It's also possible to access a Midi interface which has been plugged into the Amiga's serial port. So musicians will be able to control their instruments directly from AMOS Basic. Wow! As you would expect, full multitasking is supported. Opening the serial port SERIAL OPEN (Opens a channel for Serial I/O) -------------------------------------------- SERIAL OPEN Channel, Port_no [,Shared, Xdisabled, 7wires] Opens a communication channel to a serial device. Channel This is an identification number which will be used for all subsequent communication commands. Allowable values range from 0 to 3. Port_no Specifies the logical device number of the serial port. Normally, this value should be set to zero. However, if you've plugged a MULTI SERIAL card into your Amiga, you can access your additional ports using the numbers from one onwards. Shared (optional) This is a flag which informs AMOS that the device can be shared with other tasks which are currently running on your Amiga. It's used in multitasking. A value of FALSE (zero) will grab the channel for AMOS Basic, and will deny access to any other program. If it's is set to TRUE (-1), the serial port can be shared between several programs in memory. Beware: This system must be used with extreme care or the Amiga could easily crash! Xdisabled (optional) Toggles XON/XOFF checking during transmission of your data over the serial line. It's essential to set this flag when you are first opening the device, even if it will only be required later. The default value is FALSE (0) and disables the system. If you want to enable the checking, use a value of TRUE (-1). After the port has been opened, you'll then need to set the XON and XOFF characters using a separate call to the SERIAL X command. 7Wires (optional) A value of TRUE (-1) tells the device to use the 7 wires system as explained in the official Commodore documentation. The default is FALSE (0). When you call the Serial Open command for the first time, it will automatically load the SERIAL.DEVICE library from your system disc. So make sure it's available from the current drive. Default settings depends on the number in "Port_no": -Port_no=0 refers to the default serial port, it will be opened using the parameters set in the "Preference" workbench program. You should open this port if you use the workbench. -Port_no=1 refers to the built in serial port. Every Amiga has one. This is the port you should open. The default settings will be set for this port to use the French minitel: 1200 Baud, 7 bits, 1 stop bit, Even parity. This can be easily changed using the SERIAL SPEED, SERIAL BIT or SERIAL PARITY instructions if required. -Port_no>1 can only be used if you have a multi-serial card. Closing the serial port SERIAL CLOSE (Closes one or more serial channels) ------------------------------------------------- SERIAL CLOSE [Channel] If you don't include the channel number, SERIAL CLOSE will close all currently opened serial channels with absolutely no error checking. The optional channel number allows you to close a single channel and uses all the normal error checks. Note: Whenever a program is RUN from AMOS Basic, any opened channels will be automatically closed for you. Sending information through the serial port SERIAL SEND (Output a string via a serial channel) --------------------------------------------------- SERIAL SEND Channel, t$ Sends the string t$ straight to the specified serial channel. It does not wait for the data to be transmitted through the actual port. You'll therefore need to use the =SERIAL CHECK(Channel) function to detect when the transmission has been completed. SERIAL OUT (Outputs a memory block via a serial channel) --------------------------------------------------------- SERIAL OUT Channel, Address, Length This is identical to Serial Send except that it works with RAW data. Address is the address of your data in memory. Length is the number of bytes to be sent. Reading information from the serial port SERIAL GET (Gets a byte from a serial device) ---------------------------------------------- =SERIAL GET(Channel) Reads a single byte from the serial device. If nothing is available a value of -1 will be returned. SERIAL INPUT$ (Gets a string from the serial port) --------------------------------------------------- =SERIAL INPUT$(Channel) Reads an entire string of characters from the serial port. If there's no data, the command will return an empty string "". Otherwise the string will contain all the bytes which have been sent over the serial line up to the present time. Be careful when using this command with high speed transfers (such as MIDI). If you wait too long between each SERIAL INPUT$ command, you can overload the system completely, and generate annoying errors such as "string too long" or "serial device buffer over-run". Setting the serial parameters SERIAL SPEED (Sets the transfer baud rate for a serial channel) ---------------------------------------------------------------- SERIAL SPEED Channel, Baud rate Sets the current transfer rate of the appropriate channel. The same value will be used for both reading and writing operations. Note that you can't set split baud rates for a single channel. If the baud rate you have specified is not supported by the current device, it may be rejected by the system. SERIAL BITS (Sets the Nbit & Stopbit part of a protocol) --------------------------------------------------------- SERIAL BITS Channel, Nbits, Stopbits Assigns the number of bits which will be used for each character you transmit. Nbits is the number of bits Stopbits is the number of STOP bits SERIAL PARITY (Sets the parity checking, correct version) ---------------------------------------------------------- SERIAL PARITY Channel, Parity Sets the parity checking you are using for the current serial channel. Here's a list of the available options. Parity can have 5 different states: -1 : no parity 0 : EVEN parity 1 : ODD parity 2 : SPACE parity 3 : MARK parity See the Commodore documentation for a full explanation of this system. SERIAL X (Sets XON/XOFF) ------------------------- SERIAL X Channel, Xmode (Activates/deactivates the XON/XOFF handshaking system) A value of TRUE for Xmode disables handshaking. Any other value turns it on. Xmode should be loaded with the correct control characters. These must be specified in the following format: Xmode=XON*$10000000+XOFF*$10000 Check Commodore's documentation for more information. Other commands SERIAL BUFFER (Sets the size of the serial buffer) --------------------------------------------------- SERIAL BUFFER Channel, Length Allocates length bytes of buffer space for the required channel. Note that the default value is 512 bytes and the minimum allocation is 64 bytes. It's a good idea to increase the buffer size for high speed transfers. SERIAL FAST (Switches on FAST transfer mode) --------------------------------------------- SERIAL FAST Channel This sets a special fast flag in the current device and disables a lot of internal checking which would otherwise slow down the communication process. Use it for high speed transfers such as MIDI. Warning: When you call this command, the protocol will be changed to: PARITY EVEN,NO XON/XOFF and 8 bits. SERIAL SLOW (Switches serial transfer back into SLOW mode) ----------------------------------------------------------- SERIAL SLOW Channel Slows the serial device back to normal speed and reactivates all the error checks. SERIAL CHECK (Reports on current serial device activity) --------------------------------------------------------- =SERIAL CHECK(Channel) Asks the device for a read-out of its current status. You can use it to check whether all the information you've transferred with a previous SERIAL SEND command has been sent. CHECK=FALSE (0) -> if the last serial command is still being executed. CHECK=TRUE (-1) -> All done! SERIAL ERROR (Reports success or failure of last transfer) ----------------------------------------------------------- =SERIAL ERROR(Channel) Looks for the ERROR byte in the serial device. A value of zero indicates that everything is fine. Otherwise, the last transmission was faulty. Sending large strings Transmitting a large string may take quite a long time, especially at low baud rates. As AMOS is multitasking, your program will continue to run AFTER a SERIAL SEND instruction. It's essential to avoid provoking a garbage collection before the transfer has been completed, otherwise your data will be corrupted. So: Use the =SERIAL CHECK function before doing a lot of string work. Perform a garage collection using X=FREE to ensure that your program will not provoke one automatically. Use the SERIAL OUT channel,address,length instruction with 'address' containing the location of a previously reserved memory bank. More information More information about the Amiga's serial system can be found in the Commodore ROM KERNEL Reference Manual, Library and Devices. This will allow expert users to make maximum use of the serial device. Searching for the current devices. ---------------------------------------------------------------------------- AMOS can report back to you the current list of devices using the following commands. =DEV FIRST$ (Get first device from the current device list) ------------------------------------------------------------ dev$=DEV FIRST$("filter") Works the same as Dir First$ and Dir Next$, but reports back the device list. Note that you should remove the spaces with -" " to get the right name. =DEV NEXT$ (Get the next device satisfying the filter) ------------------------------------------------------- dev$=DEV NEXT$ Gets the next device from the device list. A null string indicates the end of the list has been reached. Example: Print Dev First$ Do A$=Dev Next$ A$=A$-" " If A$="" then End Print A$ Loop ABOUT CONFIGURATION FILES (to read only if you come from V1.2x). -------------------------------------------------------------------------- AMOS1.3 needs a new configuration file called "AMOS1_3_PAL.ENV" or "AMOS1_3_NTSC.ENV". You'll also find on your updated disc a new configuration program call CONFIG1_.AMOS. This new program has on new option: "Load AMOS1.2 configuration". As you can imagine, this option turns your 1.2 configuration file into a 1.3 configuration file, without modifying your settings. Be careful with the extensions: the Config1_3 program adds ".Lib" to all extensions name found in the "Extensions loaded" list, and the new extension name are not compatible any more with the old ones. This is perfect for all official extension: Compact, Music, Request, Serial. but AMOS will refuse to boot if any other extension is found in the list. So erase ALL unwanted extensions BEFORE saving your 1.3 configuration! Loading AMOS from within a folder. -------------------------------------------------------------------------- Although it is perfectly possible to copy the AMOS_System folder in the middle of another folder (explained later), you should avoid to do so, if you do not want later hassle with other programs that DO assume the position of the AMOS_System folder (like the 3d extension for example, and a number of other extensions). AMOS does a number of housekeeping chores before fully loading up and presenting itself to you. One of these is to locate all its default files like the sprite pointer, default font and so on. The procedure and logic it uses is as follows: 1 Check the current system to define if a PAL or NTSC screen is in use. 2 Depending on the system it will look for the AMOS1_3_PAL.Env or AMOS1_3_NTSC.Env. 3 Failing to find one of these files, it will look for the AMOS System folder in the root directory of the current drive. If this also fails, AMOS gives up trying to load and returns to the Workbench. 4 If AMOS picks up Default.Env at point 2, it will examine the environment file to find out where the other files are located. This is the key to relocating AMOS anywhere on a disc. Let's assume we want to set up AMOS within a folder called UTILS on a hard disc. First we must copy across the following files from the AMOS Program disc to the hard disc path Dh0:UTILS/ AMOS_System A folder containing all the default files AMOS1.3 The Main AMOS file The files AMOS1_3_PAL.Env and AMOS1_3_NTSC.Env must be moved from the AMOS system folder to the Utils folder. AMOS_System AMOS1.3 AMOS1_3_PAL.Env AMOS1_3_NTSC.Env Now we must change the Env files so that they tell AMOS where all the data files are. To do this you'll have to boot a normal copy of AMOS and run the Config.AMOS program. Simply ensure that the loaded extensions and default files have the correct path and filenames. In our example all the files are inside the directory AMOS_System. Just make sure that the extensions read as follows: 1-:AMOS_System/Music 2-:AMOS_System/Compact 3-:AMOS_System/Request 4-:AMOS_System/3D ;Only if you have AMOS 3D 5-:AMOS_System/Compiler ;Only if you have the AMOS Compiler 6-:AMOS_System/Serial The default filenames must be set as: 1-:AMOS_System/Def_Icon 2-:AMOS_System/Mouse.Abk 3-:AMOS_System/Default.Font 4-:AMOS_System/Default.Key An important point to note is that only the extra part of the pathname is required. AMOS adds AMOS_System onto the current path (in this case Dh0:UTILS) to find the full path: Dh0:UTILS/AMOS_System/ Hard disc users will find this information very helpful and it will avoid having the AMOS_System folder stuck in the root directory of the hard disc. Anyone developing a CDTV application in AMOS will also need to use this feature. The above information is also true for the RAMOS runtime system, the only difference being that RAMOS doesn't require the PAL or NTSC files. IMPORTANT: AMOS 1.3 needs the W.LIB to work. This file includes all graphic primitive such as screens sprites and bobs. To locate this file on the disc, AMOS takes the pathname of "Mouse.Abk" file, remove the "Mouse.Abk" and replace it by "W.Lib". So you MUST put this file near Mouse.Abk, otherwise AMOS1.3 WILL NOT LOAD! The future of AMOS. --------------------------------------------------------------------------- AMOS will constantly be updated so that it keeps up-to-date with new trends on the Amiga scene. For the latest AMOS update information contact Sandra Sharkey of the AMOS PD. Library: 25 Park Road, Wigan, WN6 7AA, England. Telephone 10am to 3pm on (0942) 495261.