Apple II File Type Notes _____________________________________________________________________________ Developer Technical Support File Type: $B3 (179) Auxiliary Type: All Full Name: ProDOS 16 or GS/OS Application Short Name: GS/OS Application Revised by: Dave Lyons March 1991 Written by: Dave Lyons & Matt Deatherage September 1989 Files of this type and auxiliary type contain application programs for the Apple IIgs. Changes since September 1989: Added a note about the state of the Super Hi-Res screen. _____________________________________________________________________________ Files of type $B3 contain GS/OS application programs. These files contain program code in Object Module Format (OMF) that is loaded by the System Loader or ExpressLoad at an address and is then executed in a documented environment. The environment and constraints for application programs are documented in GS/OS Reference; all developers creating file of type $B3 should be familiar with this material. OMF is documented in GS/OS Reference and the APW Reference Manual. The auxiliary type for $B3 files is now defined to indicate properties of the program contained within the file. Other parts of the system may use this information to properly control the environment for the program: bits 31-16 reserved must be 0 bits 15-8 signature byte. $DB means bits 7-0 are valid bits 7-3 reserved must be 0 bit 2 Message Aware: 1 = uses Message Center message #1 0 = ignores Message Center message #1 bit 1 Desktop Application: 1 = uses desktop tools such as (at least) QuickDraw II, Event Manager, Window Manager, Control Manager, and Menu Manager 0 = doesn't use desktop tools bit 0 GS/OS Aware: 1 = uses long prefixes (for example, prefix 9 instead of prefix 1) 0 = uses short prefixes (less than 63 characters) Note: If an application has the Desktop Application bit set, it should be prepared to get control with either the text or the Super Hi-Res screen visible. For example, if some error prevents the application from using the desktop tools, it may be necessary to call GrafOff before the user can read error messages displayed on the text screen (although GrafOff is a QuickDraw II call, it's OK to call GrafOff even if QuickDraw II is not active).