FORCE BOOT MODE (FBM)  For the A1200/4000  By Mike McCallum Warning: this software requires Kickstart V39 (KS 3.0) or better. Ed: Here's a way to get more control over how your AGA machine handles old games, another fine utility from Mike who has created numerous useful things over the years.  <> 34 <%> 34 <%> 34 <%> 34 <%> 34 <%> 34 <%> 34 <%> 34 <%> 34 <%> 34 <> INTRODUCTION The new Amigas, the A1200 and the A4000, have new graphics modes and capabilities which, unfortunately, are incompatible with previous methods of accessing the hardware directly. The solution for new software is to use the operating system when accessing the hardware, rather than accessing the hardware directly. This ensures that the software has the best chance possible to be compatible with future Amigas. However, this does not address the large volumes of software that has already been written for the Amiga that accesses the hardware directly. In order that older games work on the new Amigas, and to provide a changeover period for developers, the new Amigas have an ECS compatibility mode, allowing older games to access the hardware directly without causing compatibility problems. When booting the Amiga to start an older game, the user has the choice, via the Display Options submenu of the Amiga Early Startup Control menu, to force the custom chips to use the older ECS chip mode. The user can also choose whether the Amiga will be in PAL or NTSC display mode, allowing the user to decide whether to play a game in PAL or NTSC mode. In order to minimise inconvenience to the user, the chips are automatically in ECS chip mode when the boot block is executed. This is done because games that start up from the boot block are highly likely to access the hardware directly, and cause problems in true AGA mode. If the boot block is a normal boot block, control will return to the machine's boot routine, and the chips will be placed in whatever display and chip mode the user chose. The advantage of this scheme is that most games that access the hardware directly (those that start from the boot block) are automatically run in ECS mode. However, because the user's seleced mode has not yet taken effect, the user has no choice about what display mode (PAL or NTSC) a game uses when that game starts from the boot block. FORCE BOOT MODE The solution is ForceBootMode, or FBM for short. FBM is a program that installs a resident module which forces the boot routines to set the user's selected chip and display modes before the boot block is executed, allowing games that start from the boot block to be played in either PAL or NTSC mode, at the user's discretion. FBM can be used from the CLI or from the Workbench, but the greatest versatility is gained by using FBM from the CLI. When run from the CLI, FBM will not "take control" of the CLI after installing the FBM module. Using FBM is simple. To use FBM: FBM [ONCE|KEEP|KILL|INFO] Only one of either ONCE, KEEP, KILL or TEST is permitted. The options are not case sensitive. This is what the options do: FBM ONCE Installs FBM. FBM will only remain active for one boot. FBM KEEP Installs FBM. FBM will remain active until deactivated with FBM KILL, or forcibly removed from memory (by an errant or rude program). FBM KILL Deactivates FBM. Note that FBM can't actually be (safely) removed from memory, and so it is simply deactivated. FBM only occupies 200 bytes of memory. FBM INFO Shows the current status of FBM. FBM's Workbench interface is simple: double click on the FBM icon. This will install FBM as if "FBM KEEP" had been typed into a CLI. If anything goes wrong when run from the Workbench, the screen will flash (or the bell will sound, according to how your preferences are set). Only two things can go wrong when FBM is run from the Workbench: you are using a Kickstart prior to V39 (KS 3.0), or there wasn't enough memory. NOTES Some games forcibly remove FBM from memory, either by taking complete control of the machine, or by clearing memory. Even if a game does remove FBM, it will not be until after FBM has performed its magic (although you will still need to re-install FBM to use it again). Type "FBM TEST" to see if FBM is still present. Note that FBM sets both the display mode and the chip mode before boot block execution. This means that many games may suddenly appear to not work. Simply choose ECS chip mode from the display options menu in the Amiga Early Startup Control menu. When FBM is removed by "FBM KILL", the memory used by the resident portion of FBM cannot safely be recovered (without possible compromise to the system), so FBM is simply deactivated. In any case, FBM only uses 200 bytes of memory. LICENCING AGREEMENT By distributing this package, you agree to adhere to this licencing agreement. You are licenced to distribute this package in any way you see fit with the following limitations: * All files associated with this package are distributed together. These are: + FBM + FBM.info + FBM.doc + FBM.doc.info * No part of this package may be modified, with the following exceptions: + Translating the documentation into another language. + Reformatting the documentation to suit your taste or text viewer. + Altering the default tool of the icon FBM.doc.info. * You may charge no more than the cost of obtaining a disk direct from Fred Fish for distribution. (The only exception to this limitation is MegaDisc Australia, for whom this software was originally written.) WARRANTY This package is supplied as is, without any warranties, either expressed or implied, as to its fitness for any purpose. The only thing this package is guaranteed to do it occupy space on a storage device. THE AUTHOR I (Mike McCallum) can be contacted by any of these means: Post: Mike McCallum 117 Morrison Road Midland WA 6056 Phone: (09)274-3390 FidoNet: Mike McCallum 3:690/508 Please feel free to forward any comments, bug reports, money, gifts or even post cards to me.  <> 34 <%> 34 <%> 34 <%> 34 <%> 34 <%> 34 <%> 34 <%> 34 <%> 34 <%> 34 <>